JP2008125112A - Visual processing apparatus, display apparatus, visual processing method, program and integrated circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a visual processing apparatus, a display apparatus, an imaging apparatus, a mobile information apparatus and an integrated circuit wherein even when an image having a steep edge region is input or even when a special image is input, any side effect can be suppressed and wherein a simple structure is used to change the intensity of the visual processing of images in real time. <P>SOLUTION: A spatial processing part (2) generates an unsharp signal US from an input signal IS. A target level establishing part (4) establishes a target level value L for establishing a range in which the intensity of the visual processing is adjusted. An effect adjusting part (5) combines, in accordance with an externally established effect adjustment signal MOD, the target level value L with the unsharp signal US to generate a combined signal MUS. A visual processing part (3) outputs an output signal OS in accordance with the input signal IS and combined signal MUS. In this way, the intensity of the visual processing can be changed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a visual processing device, a display device, a photographing device, a portable information device, and an integrated circuit, and in particular, a visual processing device, a display device, a photographing device, a portable information device, and an integrated circuit that change the strength of visual processing of an image. About.

As visual processing of an image signal of an original image, spatial processing and gradation processing are known.
Spatial processing is to perform processing of a pixel of interest using pixels around the pixel of interest that is the target of filter application. In addition, there is known a technique for performing contrast enhancement of an original image, dynamic range (hereinafter referred to as “DR”) compression, and the like using a spatially processed image signal (for example, Patent Document 1).
The gradation processing is processing for converting a pixel value using a look-up table (hereinafter referred to as “LUT”) for each target pixel regardless of pixels around the target pixel, and is called gamma correction. Sometimes. For example, when contrast enhancement is performed, pixel values are converted using an LUT that sets gradations of gradation levels with a high appearance frequency (large area) in the original image. As gradation processing using the LUT, gradation processing (histogram equalization method) that determines and uses one LUT for the entire original image, and determines and uses the LUT for each of the image areas obtained by dividing the original image into a plurality of parts. Gradation processing (local histogram equalization method) is known.

A conventional visual processing device includes a plurality of profile data having different conversion characteristics, and realizes the above different visual processing by switching the profile data (for example, Patent Document 2).
Hereinafter, a conventional visual processing device 900 will be described with reference to FIG. 47, the visual processing device 900 performs spatial processing on the luminance value for each pixel of the original image acquired as the input signal IS and outputs an unsharp signal US, and the input signal IS for the same pixel. And an unsharp signal US are used to perform visual processing of the original image and output an output signal OS. The unsharp signal US is a local area brightness signal obtained by processing the luminance signal with a low-pass filter, and is a blur signal. The visual processing unit 902 is configured by a two-dimensional LUT.

The visual processing unit 902 performs gamma correction having tone conversion characteristics shown in FIG. 48, selects a tone conversion curve corresponding to the unsharp signal US in the region of interest in the image, and increases or decreases the contrast. I was doing. For example, the dark region in the image is brightened by selecting the curve of the unsharp signal US0, and conversely, the bright region is selecting the unsharp signal USn curve to suppress the brightness and increase the contrast. These curve groups are called profiles.
The profile data registration apparatus 903 has different visual processing profile groups, and registers profile data optimum for the desired visual processing in the visual processing unit 902.
Further, the profile data registration device 903 has been updated to necessary profiling data according to the strength of visual processing.
For example, if you want to change the intensity of contrast enhancement in the dark area when the face is extremely dark or slightly dark even in a backlit image, update the profile data with optimal tone conversion characteristics and adjust the brightness. Was.
US Pat. No. 4,667,304 International Publication No. 2005/027043 Pamphlet

(Problems to be solved by the invention)
However, the above-described conventional configuration has a problem that the amount of data increases because it is necessary to prepare profile data according to the strength of the effect of visual processing. As the amount of data increases, the memory capacity for storing profile data increases (usually several hundred bytes to several tens of kilobytes).
In addition, there is a problem that it is necessary to update the profile data according to the strength of the effect of visual processing. Since much update time is required for updating the profile data, there is a problem that the effect of visual processing cannot be changed in real time for each local region in the image. In particular, when the visual processing unit is configured with a two-dimensional LUT, the amount of data increases, and more update time is required.

Further, as an image quality improvement process close to human vision, there is a visual process for converting the value of the target pixel based on the comparison between the value of the target pixel and the values of the pixels in the surrounding area. In such visual processing, brightness information is extracted from a wide range of areas around the position of the pixel of interest in order to further enhance the processing effect.
However, since the value of the pixel of interest is determined from the comparison between the value of the pixel of interest and the values of the surrounding pixels, if there is a steep edge region in the peripheral region, it is affected by the values of the surrounding pixels. Even in a flat region where the pixel value hardly fluctuates, the output of visual processing changes gently in the vicinity of the edge. When a large luminance change occurs in a flat region, a shadow-like contour is generated in the region adjacent to the edge, resulting in an unnatural image. In addition, an image with a small ratio of edge area, an image with a small number of gradations, an image with a small difference in luminance from adjacent pixels and a large number of similar values continuously generated, or a block image divided into multiple high-frequency components When visual processing is performed in the same manner as a natural image on an image that contains a small number of blocks (hereinafter referred to as “special image”), the luminance change in the flat area is easily noticeable. A shadow-like contour occurs in the area adjacent to the edge, resulting in an unnatural image.
The problem to be solved by the present invention is that even if an image having a steep edge region or a special image is input, side effects can be suppressed, and the visual processing of the image can be performed with a simple configuration. A visual processing device, a display device, a visual processing method, a program, and an integrated circuit capable of changing the strength in real time are realized.

(Means for solving the problem)
According to a first aspect of the present invention, there is provided a visual processing device that visually processes and outputs an input image signal, an effect adjustment unit that performs a process for setting an effect of visual processing in accordance with the effect adjustment signal, and a visual image signal. And a visual processing unit that performs processing.
Thereby, the effect of the visual processing can be set with a simple configuration by the effect adjustment signal. Therefore, the effect of visual processing can be adjusted in real time.

A second invention is the first invention, comprising: a target level setting unit that sets a predetermined target level; and a spatial processing unit that performs predetermined spatial processing on an image signal and outputs a processed signal. Further prepare. The effect adjustment unit outputs a composite signal obtained by combining a predetermined target level and a processing signal in accordance with an effect adjustment signal for setting the effect of visual processing. The visual processing unit performs tone conversion of the image signal based on the composite signal and the image signal.
With such a configuration, different composite signals are generated according to the effect adjustment signal and the strength of visual processing is changed, so that the predetermined gradation conversion function need not be changed in accordance with the degree of strength. If the predetermined gradation conversion function is implemented by a hardware circuit, it is not necessary to have a plurality of circuits corresponding to the strength of visual processing, so the circuit scale can be reduced. If the predetermined gradation characteristics are implemented with profile data stored in the two-dimensional LUT, it is not necessary to have a plurality of profile data according to the strength of the visual effect, so that the memory capacity can be reduced. Further, since it is not necessary to update the profile data according to the strength of the visual processing, the strength of the visual processing can be changed even if the visual processing unit is configured with a two-dimensional LUT. Also, by setting the target level in the target level setting unit, it is possible to set to what gradation characteristics the visual processing effect is changed in the visual processing realized by the visual processing device.

A third invention is the first invention, a target level setting unit that sets a predetermined target level, a spatial processing unit that performs predetermined spatial processing on an image signal and outputs a processed signal, and an image A correction unit that corrects the signal. The effect adjustment unit outputs a composite signal obtained by combining a predetermined target level and a processing signal in accordance with an effect adjustment signal for setting the effect of visual processing. The visual processing unit outputs a gain signal based on the composite signal and the image signal. The correction unit corrects the image signal based on the gain signal.
With such a configuration, the strength of visual processing can be changed by generating different composite signals depending on the effect adjustment signal, so that a predetermined gain function can be fixed. If the predetermined gain function is implemented by a hardware circuit, it is not necessary to have a plurality of circuits according to the strength of visual processing, so that the circuit scale can be reduced. If the predetermined gain function is implemented with the profile data stored in the two-dimensional LUT, it is not necessary to have a plurality of profile data according to the strength of visual processing, so that the memory capacity can be reduced. Further, since it is not necessary to update the profile data according to the strength of the visual processing, the strength of the visual processing can be changed in real time even if the visual processing unit is configured with a two-dimensional LUT.

4th invention is 1st invention, Comprising: The spatial processing part which performs predetermined | prescribed spatial processing with respect to an image signal, and outputs a processing signal is further provided. The effect adjustment unit outputs a synthesized signal obtained by synthesizing the image signal and the processing signal in accordance with the effect adjustment signal for setting the effect of visual processing. The visual processing unit performs tone conversion of the image signal based on the composite signal and the image signal.
With such a configuration, the effect adjustment unit generates a combined signal obtained by internally dividing the image signal and the processing signal by the effect adjustment signal. Thereby, the effect of visual processing can be changed from the characteristic of only gamma conversion for converting a predetermined brightness to the characteristic of local contrast conversion. Even when the effect of visual processing is changed, a predetermined gradation conversion function can be fixed.
5th invention is 1st invention, Comprising: The spatial processing part which performs predetermined | prescribed spatial processing with respect to an image signal, and outputs a processing signal, and the correction | amendment part which correct | amends an image signal are further provided. The effect adjustment unit outputs a synthesized signal obtained by synthesizing the image signal and the processing signal in accordance with the effect adjustment signal for setting the effect of visual processing. The visual processing unit outputs a gain signal based on the synthesized signal and the image signal. The correction unit corrects the image signal based on the gain signal.
With such a configuration, the effect adjustment unit generates a combined signal obtained by internally dividing the image signal and the processing signal by the effect adjustment signal. Thereby, the effect of visual processing can be changed from the characteristic of only gamma conversion for converting a predetermined brightness to the characteristic of local contrast conversion. Even when the effect of visual processing is changed, the predetermined gain function can be fixed.

A sixth invention is any one of the first to fifth inventions, wherein the visual processing unit has a two-dimensional lookup table.
With such a configuration, different visual effect profiles such as DR compression, local contrast, and gradation processing can be registered. Further, by storing data based on the gain characteristics in the two-dimensional LUT, the memory capacity can be reduced as compared with storing the gamma conversion value as data as it is.
7th invention is 1st invention, Comprising: The surrounding image information extraction part which extracts the surrounding image information of the input image signal, and the effect adjustment which outputs the effect adjustment signal for setting the effect of visual processing And a signal generator. The visual processing unit visually processes the image signal based on the image signal and the peripheral image information. The effect adjustment unit sets the effect of visual processing according to the effect adjustment signal.
According to this configuration, the effect of visual processing can be set (differentiated) according to the effect adjustment signal, and the side effect can be suppressed by adjusting the effect in the region where the side effect occurs.

The eighth invention is the seventh invention, wherein the effect adjustment signal generator detects an area adjacent to the edge area from the image signal and outputs an effect adjustment signal.
According to this, even when an image having a steep edge region is input, side effects in the vicinity of the edge region can be suppressed.
The ninth invention is the eighth invention, wherein the effect adjustment signal generator detects a flat region adjacent to the edge region from the image signal and outputs an effect adjustment signal.
According to this, the side effect of the flat area in the vicinity of the edge area where the side effect is easily noticeable can be suppressed.

A tenth aspect of the invention is the eighth or ninth aspect of the invention, in which the effect adjustment signal generator outputs an effect adjustment signal in accordance with the amount of change in the peripheral image information.
According to this, it is possible to further suppress side effects that occur with changes in the peripheral image information.
The eleventh invention is the eighth or ninth invention, wherein the effect adjustment signal generator detects a flatness level of a flat area in which a luminance difference from an adjacent area is a predetermined value or less from an image signal. And an edge detection unit that detects an edge amount of an edge region where a luminance difference between adjacent regions is a predetermined value or more from the image signal. The effect adjustment signal generator outputs an effect adjustment signal based on outputs from the flatness detection unit and the edge detection unit.
According to this, even when an image having a steep edge region is input, side effects of a flat region near the edge region can be suppressed.

The twelfth invention is the invention according to any one of the seventh to eleventh inventions, wherein the effect adjustment unit outputs a first synthesized signal obtained by synthesizing the image signal and the peripheral image information in accordance with the effect adjustment signal. To do. The visual processing unit visually processes the image signal based on the first synthesized signal and the image signal.
According to this, the visual processing unit can select different gradation conversion processing based on the first composite signal, and can visually process the image signal by the selected gradation conversion processing. The effect of visual processing can be varied.
A thirteenth invention is any one of the seventh to eleventh inventions, wherein the effect adjustment unit combines the image signal and the output visually processed by the visual processing unit in accordance with the effect adjustment signal. 2 composite signal is output.
According to this, it is possible to change the ratio between the image signal and the processing signal in accordance with the effect adjustment signal, and to make the visual processing effect different.

14th invention is 1st invention, Comprising: The surrounding image information extraction part which extracts the surrounding image information of the input image signal, and the degree which is a special image which has the bias of statistical information from an image signal And a special image detection unit that detects based on statistical information bias and outputs the detected degree as an effect adjustment signal. The visual processing unit outputs a processing signal obtained by visually processing the image signal based on the image signal and the peripheral image information. The effect adjustment unit controls the visual processing unit to set the effect of visual processing according to the effect adjustment signal.
According to this configuration, the visual processing effect can be maintained when a normal image that is not a special image is input, and side effects can be suppressed when a special image is input.

The fifteenth invention is the fourteenth invention, wherein the special image detecting unit is a statistical information bias based on a ratio of a region where the shading changes or a ratio of a region where the shading does not change in the image of the image signal. Is detected.
According to this, further, it is possible to detect a bias of statistical information from the ratio of the area where the shading changes in the image of the image signal or the ratio of the area where the shading does not change.
The sixteenth invention is the fifteenth invention, wherein the special image detection unit increases the degree of being a special image when the ratio of the area where the shading changes is small or when the ratio of the area where the shading does not change is large. To do.
Accordingly, the degree of special image can be detected, and an effect adjustment signal suitable for special image processing can be output.

The seventeenth invention is the sixteenth invention, wherein the special image detecting unit detects a ratio of a region where the density changes by detecting an edge component in the image.
According to this, it is possible to detect the ratio of the region where the density changes from the edge component in the image.
The eighteenth aspect of the invention is the sixteenth aspect of the invention, in which the special image detection unit detects a ratio of a region in which the density does not change by detecting the flatness in the image.
According to this, it is possible to detect the ratio of the region where the density does not change from the degree of flatness in the image.

In a nineteenth aspect based on the eighteenth aspect, the special image detection unit detects the degree of flatness based on the number of gradation levels or the continuous length of similar pixels.
According to this, the flatness can be detected from the number of gradation levels in the image or the continuous length of similar pixels.
The twentieth invention is the seventeenth invention, wherein the special image detecting unit detects an edge detection unit for detecting an edge amount for each pixel from the image signal, and detects an edge pixel having an edge amount equal to or larger than a predetermined value. An edge density calculation unit that calculates the ratio of the number of edge pixels to the total number of pixels of the image signal, and a first effect adjustment signal generation unit that outputs an effect adjustment signal according to the ratio.
According to this, a special image can be detected from the edge in the image, and an effect adjustment signal corresponding to the deviation of the ratio of edge pixels in the special image can be generated.

The twenty-first invention is the seventeenth invention, wherein the special image detection unit detects a high-frequency block including a high-frequency component from the image signal divided into a plurality of blocks, and a plurality of blocks A high-frequency block density detection unit that detects a ratio of the number of high-frequency blocks; and a second effect adjustment signal generation unit that outputs an effect adjustment signal according to the ratio.
According to this, a special image can be detected by detecting a high-frequency block in the image, and an effect adjustment signal corresponding to the bias of the ratio of the high-frequency block in the special image can be generated.
The 22nd invention is the 19th invention, wherein the special image detecting unit compares the frequency detecting unit for detecting the frequency for each gradation level from the image signal and the frequency for each gradation level with a predetermined threshold value. A frequency determination unit for detecting a gradation level having a frequency greater than a predetermined threshold, a gradation number detection unit for detecting the number of gradation levels determined to be high by the frequency determination unit, and a number of gradation levels And a third effect adjustment signal generator for outputting an effect adjustment signal in response.
According to this, a special image can be detected from the number of gradation levels in the image, and an effect adjustment signal corresponding to the deviation of the number of gradation levels in the special image can be generated.

A twenty-third invention is the nineteenth invention, wherein the special image detection unit includes a similar luminance detection unit, a continuous length detection unit, an average continuous length calculation unit, and a fourth effect adjustment signal generation unit. Have. The similar luminance detection unit detects a similar pixel in which the luminance difference between adjacent pixels is equal to or less than a predetermined value from the image signal. The continuous length detection unit detects a continuous length in which similar pixels are continuous. The average continuous length calculation unit calculates the average continuous length by averaging a plurality of continuous lengths detected by the continuous length detection unit. The fourth effect adjustment signal generator outputs an effect adjustment signal according to the average continuous length.
According to this, a special image can be detected from the average continuous length of similar pixels in the image, and an effect adjustment signal corresponding to the bias of the average continuous length in the special image can be generated.

A twenty-fourth aspect of the invention is any one of the fourteenth to twenty-third aspects, in which the effect adjustment unit changes the ratio between the image signal and the peripheral image information in accordance with the effect adjustment signal and performs the first synthesis. The signal is output, and the visual processing unit visually processes the image signal based on the first synthesized signal and the image signal.
According to this, the visual processing unit can select different gradation conversion processing based on the first composite signal, and the effect of visual processing can be made different.
A twenty-fifth aspect is the invention according to any one of the fourteenth to twenty-third aspects, wherein the effect adjustment unit combines the image signal and the processing signal by changing the ratio according to the effect adjustment signal. Is output.
According to this, it is possible to change the ratio between the image signal and the processing signal in accordance with the effect adjustment signal, and to make the visual processing effect different.

A twenty-sixth aspect of the invention is any one of the fourteenth to twenty-third aspects, wherein the visual processing unit has a two-dimensional lookup table and is visually based on characteristic data set in the two-dimensional lookup table. Process. The effect adjustment unit sets the characteristic data synthesized by changing the ratio of the plurality of characteristic data having different visual processing effects according to the effect adjustment signal in the visual processing unit.
According to this, it is possible to perform visual processing using characteristic data synthesized by changing the ratio of a plurality of characteristic data having different visual processing effects according to the effect adjustment signal, and the visual processing effects can be varied.
A twenty-seventh aspect is the invention according to any one of the fourteenth to twenty-sixth aspects, wherein the special image detection unit inputs a reduced image in which the image signal is reduced, and the statistical information is biased from the reduced image. A special image is detected, and an effect adjustment signal is output based on the statistical information bias.
This further suppresses the influence of noise when detecting a special image. In addition, the amount of processing can be reduced.

The twenty-eighth aspect is the invention according to any one of the fourteenth to twenty-seventh aspects, wherein the special image detecting unit is more than one or more previous frame images when the image signal is a frame image, or when the image signal is a field image. Statistical bias is detected from one or more previous field images.
According to this, a special image can be detected from the immediately preceding frame, and an effect adjustment signal corresponding to the bias of information of the special image can be used from the beginning of the frame. In addition, a special image can be detected from the previous field, and an effect adjustment signal corresponding to the bias of the special image information can be used from the beginning of the field.

The twenty-ninth invention is the twenty-eighth invention, further comprising a continuous change processing unit for continuously changing the effect adjustment signal. The continuous change processing unit continuously changes the effect adjustment signal between frames when the effect adjustment signal is output in units of frames, and between fields when the effect adjustment signal is output in units of fields.
According to this, it is possible to further suppress an abrupt change in the effect adjustment signal between frames, and to suppress image flicker between frames. In addition, a sudden change in the effect adjustment signal between the fields can be suppressed, and the flickering of the image between the fields can be suppressed.
A thirtieth aspect of the invention is a data receiving unit that receives image data transmitted or broadcasted, a decoding unit that decodes the received image data into video data, and outputs an output signal by visually processing the decoded video data The display device includes any one of the first to 29th visual processing devices and a display unit that displays an output signal visually processed by the visual processing device.
With such a configuration, the intensity of visual processing can be changed in real time by adjusting the brightness of the image and displayed on the display device. In addition to the display device, a photographing device or a portable information terminal device including a visual processing device can also be realized.
The imaging device may be configured to include an imaging unit that captures an image and a visual processing device that performs visual processing using an image captured by the imaging unit as an input signal.
With such a configuration, it is possible to obtain the same effect as that of the visual processing device even in the photographing device.

In addition, the portable information device includes a data receiving unit that receives image data transmitted or broadcasted, a visual processing device that visually processes the received image data and outputs an output signal, and a display of the visually processed output signal It may be configured to include display means for performing the above.
With such a configuration, the portable information device can obtain the same effect as the visual processing device.
The portable information device also includes a photographing unit that captures an image, a visual processing device that performs visual processing using the image captured by the photographing unit as an input signal and outputs an output signal, and transmits the visually processed output signal. The data transmission part which comprises may be sufficient.
With such a configuration, the portable information device can obtain the same effect as the visual processing device.

A thirty-first invention is a visual processing method for visually processing and outputting an input image signal, an effect adjustment step for performing processing for setting the effect of visual processing according to the effect adjustment signal, and an image signal Visual processing steps for performing visual processing.
Thereby, it is possible to easily set the effect of the visual processing by the effect adjustment signal. Therefore, the effect of visual processing can be adjusted in real time.
A thirty-second invention is the thirty-first invention, comprising: a target level setting step for setting a predetermined target level; and a spatial processing step for performing predetermined spatial processing on the image signal and outputting a processed signal. Also have. In the effect adjustment step, a synthesized signal obtained by synthesizing a predetermined target level and the processing signal according to the effect adjustment signal is output. In the visual processing step, the image signal is subjected to gradation conversion based on the synthesized signal and the image signal.
As a result, a different composite signal is generated according to the effect adjustment signal to change the strength of the visual processing, so that the predetermined gradation conversion function need not be changed in accordance with the degree of strength. Further, by setting the target level in the target level setting step, it is possible to set to what gradation characteristics the visual processing effect realized by this visual processing method is changed.

A thirty-third invention is the thirty-first invention, wherein a peripheral image information extraction step for extracting peripheral image information of an input image signal and an effect adjustment for outputting an effect adjustment signal for setting an effect of visual processing A signal generation step. In the visual processing step, the image signal is visually processed based on the image signal and the peripheral image information. In the effect adjustment step, the effect of visual processing is set according to the effect adjustment signal.
According to this method, it is possible to vary the effect of visual processing according to the effect adjustment signal.

A thirty-fourth aspect is the thirty-third aspect, wherein in the effect adjustment signal generation step, a flat region adjacent to the edge region is detected from the image signal and an effect adjustment signal is output.
According to this, even when an image having a steep edge region is input, the side effect of the flat region near the edge region can be suppressed.
A thirty-fifth aspect of the present invention is the thirty-first aspect, wherein a peripheral image information extracting step for extracting peripheral image information of the input image signal, and detecting a special image having a statistical information bias from the image signal, And a special image detection step of outputting an effect adjustment signal based on the degree of statistical information bias. In the visual processing step, the image signal is visually processed based on the image signal and the peripheral image information. In the effect adjustment step, the effect of visual processing is set according to the effect adjustment signal.
According to this method, the visual processing effect can be maintained when a normal image without a special image is input, and side effects can be suppressed when a special image is input.

According to a thirty-sixth aspect of the invention, an effect adjustment step of outputting a control signal for setting an effect of visual processing to a computer in accordance with an effect adjustment signal in order to perform visual processing for visually processing and outputting an input image signal And a visual processing step for visually processing the image signal based on the control signal and the image signal.
Thereby, it is possible to easily set the effect of the visual processing by the effect adjustment signal. Therefore, the effect of visual processing can be adjusted in real time.
A thirty-seventh aspect of the invention is the thirty-sixth aspect of the invention, in which a target level setting step for setting a predetermined target level in the computer, a spatial processing step for performing a predetermined spatial processing on the image signal and outputting a processing signal And a program for further executing. In the effect adjustment step, a synthesized signal obtained by synthesizing a predetermined target level and the processing signal in accordance with an effect adjustment signal for setting the effect of visual processing is output. In the visual processing step, the image signal is subjected to gradation conversion based on the synthesized signal and the image signal.
As a result, a different composite signal is generated according to the effect adjustment signal to change the strength of the visual processing, so that the predetermined gradation conversion function need not be changed in accordance with the degree of strength. Further, by setting the target level in the target level setting step, it is possible to set to what gradation characteristics the visual processing effect realized by this visual processing method is changed.

A thirty-eighth aspect is the thirty-sixth aspect, wherein a peripheral image information extraction step for extracting peripheral image information of the input image signal and an effect adjustment signal for setting the effect of visual processing are output to the computer. A program for further executing the effect adjustment signal generation step. In the visual processing step, the image signal is visually processed based on the image signal and the peripheral image information. In the effect adjustment step, adjustment is performed so that the effect of the visual processing varies according to the effect adjustment signal.
According to this program, it is possible to vary the effect of visual processing according to the effect adjustment signal.

The thirty-ninth aspect is the thirty-eighth aspect, wherein the effect adjustment signal generation step detects a flat area adjacent to the edge area from the image signal and outputs an effect adjustment signal.
According to this, even when an image having a steep edge region is input, the side effect of the flat region near the edge region can be suppressed.
The 40th invention is the 38th invention, wherein a peripheral image information extracting step for extracting peripheral image information of an input image signal and a special image having a statistical information bias from the image signal are extracted to a computer. And a special image detection step of detecting and outputting an effect adjustment signal based on the degree of statistical information bias. In the visual processing step, the image signal is visually processed based on the image signal and the peripheral image information. In the effect adjustment step, the effect of visual processing is set according to the effect adjustment signal.
According to this program, the visual processing effect can be maintained when a normal image without a special image is input, and side effects can be suppressed when a special image is input.

The forty-first invention is an integrated circuit including the visual processing device according to any one of the first to 29th inventions.
With such a configuration, it is possible to obtain the same effect as that of the visual processing device even in an integrated circuit.
(The invention's effect)
According to the present invention, even when an image having a steep edge region or a special image is input, side effects can be suppressed, and the strength of visual processing of an image can be reduced in real time with a simple configuration. A visual processing device, a display device, a visual processing method, a program, and an integrated circuit can be realized.

Hereinafter, a visual processing device according to an embodiment of the present invention will be described with reference to the drawings.
(Embodiment 1)
First, the visual processing device according to the first embodiment will be described. The visual processing performed here is processing that has characteristics close to how the human eye can see, and is processing that determines an output signal by comparing the target pixel value of the input image signal with its surrounding pixel values. . Examples of the processing to be applied include backlight correction processing, knee processing, DR compression processing, and brightness adjustment (including gradation processing and contrast adjustment).
FIG. 1 is a block diagram of a visual processing device 1 according to the first embodiment.
The visual processing device 1 performs visual processing on the image signal IS and outputs an output signal OS obtained by visual processing.

The spatial processing unit 2 acquires, from the input signal IS, pixel values of a target pixel to be subjected to spatial processing and pixels in a peripheral region of the target pixel (hereinafter referred to as “peripheral pixel”). Spatial processing is performed on the input value of each pixel of the acquired original image, and an unsharp signal US is output. The unsharp signal US is a blur signal obtained by processing the input signal IS with a low-pass filter.
The brightness including the peripheral region of the target pixel can be detected by the unsharp signal US.
The target level setting unit 4 sets a target level of an effect required in visual processing. For example, a target for changing the gradation conversion characteristic to which a required visual processing effect such as a local contrast effect or DR compression is changed is set. A function for determining the set target level value is set according to the gradation conversion characteristic to be adjusted, and the input signal IS is converted based on a predetermined function.

Specifically, the target level value L is output according to the conversion characteristic of the straight line 1 shown in FIG. Here, the straight line 1 changes the target level according to the input signal IS. For example, target level L = input signal IS. In this case, the target level setting unit 4 may be omitted.
Similarly, in the DR compression process, the target level value L is output according to the conversion characteristic of the straight line 2 shown in FIG. The straight line 2 does not change the target level according to the input signal IS. That is, the target level L = predetermined value T1 (fixed). In this case, the target level setting unit 4 may be omitted.
Note that the target level value L may be output by an intermediate conversion characteristic between the straight line 1 and the straight line 2. For example, the target level L = (input signal IS + predetermined value T1) / 2. Further, the target level value L may be output by the curve 1 set between the straight line 1 and the straight line 2.

The effect adjustment unit 5 performs an internal division operation on the target level L and the unsharp signal US in accordance with the external signal (effect adjustment signal) MOD (“internal division calculation” is, for example, 1 from two physical quantities. And a combined signal MUS is output. For example, the effect adjustment unit 5 performs an internal division calculation of MUS = (US−L) × MOD + L. The value of the external signal (effect adjustment signal) MOD is set in the range of “0” to “1”, the effect is maximum when MOD is “0”, and the maximum effect is obtained when MOD is “1”. As a modification of the equation, MUS = US × MOD + L × (1−MOD) may be used.
The visual processing unit 3 outputs an output signal OS with respect to the input signal IS and the synthesized signal MUS based on the set two-dimensional gradation conversion characteristics. Various visual effects can be realized by the gradation conversion characteristics.

Next, the visual processing device 1 according to Embodiment 1 of the present invention will be described in more detail.
First, control in the case of enhancing or weakening local contrast as an effect of visual processing will be described. Control is performed by setting an effect adjustment signal from the outside.
The visual processing device 1 is set to have a two-dimensional gradation conversion characteristic as shown in FIG. Here, the horizontal axis represents the input signal IS input, and the vertical axis represents the converted output signal OS.
The two-dimensional gradation conversion characteristic means an input / output characteristic in gradation conversion for determining an output with respect to two inputs of the composite signal MUS and the input signal IS. For example, it has a predetermined gradation conversion characteristic according to the signal levels of the composite signals MUS0 to MUSn in FIG. Accordingly, if the pixel value of the input signal IS is an 8-bit value, the pixel value of the output signal OS with respect to the value of the input signal IS divided in 256 steps is determined by a predetermined two-dimensional gradation conversion characteristic. The gradation conversion characteristic is a gradation conversion curve having a predetermined gamma conversion characteristic, and the output monotonously decreases with respect to the subscript of the composite signal MUS. Note that even if there is a portion where the output is not partly monotonically decreasing, the subscript of the composite signal MUS may be substantially monotonically decreasing. Also, as shown in FIG. 4, in the two-dimensional gradation conversion characteristics, (output value when MUS = MUS0) ≧ (output when MUS = MUS1) with respect to the brightness values of the pixels of all input signals IS Value) ≧ ... ≧ (output value in the case of MUS = MUSn). This gradation conversion characteristic enhances the contrast of the local area.

Next, the spatial processing unit 2 obtains the unsharp signal US by, for example, a low-pass spatial filter operation that allows only the low-pass space to pass through the target pixel of the input signal IS. In the filter calculation, the pixel values of the target pixel and the surrounding pixels are calculated based on, for example, US = (Σ [Wij] × [Aij]) / (Σ [Wij]). Here, [Wij] is the weighting factor of the pixel located in the i-th row and j-th column in the target pixel and the peripheral pixels, and [Aij] is located in the i-th row and j-th column in the target pixel and the peripheral pixels. This is the pixel value of the pixel. Further, “Σ” means that the sum of the target pixel and the surrounding pixels is calculated.
More specifically, the description will be made by expressing the weight coefficient [Wij] as 1 and the pixel value [Aij] as A (i, j). The pixel value of the target pixel is “128” for A (1,1), “110” for A (0,0), “115” for A (0,1), “117” for A (0,2), A (1,0) is "123", A (1,2) is "120", A (2,0) is "120", A (2,1) is "127", A (2,2) Is “125”. At this time, in order to obtain the unsharp signal US from the region of 3 pixels × 3 pixels, an operation of US = (128 + 110 + 115 + 117 + 123 + 120 + 120 + 127 + 125) / 9 may be performed.

Note that a smaller weight coefficient may be given as the absolute value of the pixel value difference is larger, or a smaller weight coefficient may be given as the distance from the target pixel is larger.
In addition, the size of the peripheral pixel area is set according to the effect. In order to obtain a visual effect, the peripheral pixel area should be set to a certain size. Is preferred. For example, when the size of the target image is XGA (1024 × 768), it is preferable to set the peripheral pixel region to a region having a size of 80 pixels × 80 pixels or more.
Further, as the low-pass spatial filter, a FIR (Finite Impulse Response) type low-pass spatial filter or an IIR (Infinite Impulse Response) type low-pass spatial filter that is usually used for generating an unsharp signal may be used. .

In the local contrast process, the target level setting unit 4 sets the conversion characteristic of the straight line 1 shown in FIG. 2, and sets the target level L = the input signal IS. Therefore, when the effect adjustment signal MOD = 0, the visual processing is “no effect”, so that the composite signal MUS = the input signal IS.
(For example, the composite signal MUS is
MUS = US × MOD + IS × (1.0−MOD)
If MOD = 0 is substituted into this equation, the composite signal MUS = the input signal IS. )
When the target level L = the input signal IS, the target level setting unit 4 is not necessary. The input signal IS may be directly input to the effect adjustment unit 5.
In the visual processing unit 3, when the composite signal MUS = the input signal IS, the two input signals IS input to the visual processing unit 3 and the composite signal MUS have the same value. Gradation conversion by the gradation conversion characteristic of curve 2 shown is executed. The tone conversion characteristic of curve 2 has only brightness adjustment (gamma conversion) characteristics and has no effect of increasing local contrast.

The effect adjustment unit 5 adjusts the required visual processing effect by setting the effect adjustment signal MOD. For example, if MOD = 0.5, the combined signal MUS is MUS = (US−L) × MOD + L, and if L = IS, the combined signal MUS = 0.5 × US + 0.5 × IS.
At this time, the synthesized signal MUS is an intermediate output between the input signal IS and the unsharp signal US, as shown in FIG. As shown in FIG. 3B, the output signal OS (MUS) visually processed by the synthesized signal MUS is only converted into the output signal OS (IS) visually processed based on only the input signal IS and the unsharp signal US. The output is intermediate with the output signal OS (US) subjected to visual processing based on this. Therefore, the visual processing device 1 outputs the output signal OS (US) that has the MOD “1” and the “maximum effect” of the visual processing, and the output signal that has the MOD “0” and the visual processing “no effect”. Output OS (IS).

Thus, the visual processing effect of local contrast can be strengthened or weakened according to the value of the effect adjustment signal MOD.
The effect adjustment unit 5 also generates a composite signal MUS obtained by internally dividing the input signal IS and the unsharp signal US by the effect adjustment signal MOD. Thereby, the effect of visual processing can be changed from the characteristic of only gamma conversion for converting a predetermined brightness to the characteristic of local contrast conversion.
Next, DR compression processing will be described with reference to FIG. In an imaging apparatus such as a camera, the DR compression process is a process for keeping the input range of a CCD for inputting an image in a recording range for recording by the photographing apparatus. In general, in an imaging device, since brightness is adjusted based on a human face, brightness is set so that the brightness of the face is about 80% of the DR of the output. Therefore, for example, a bright sky region in the background of the face needs to be included in the remaining 20% of the output DR. For this reason, “knee processing” in which the output DR is compressed and converted is generally performed from the point where the input range becomes a certain level or more as shown by the curve 4 in FIG.

However, when a bright bright area signal such as the sky is compressed and stored in a range of 20% of the output DR, shadows such as clouds may fly due to insufficient gradation.
Therefore, as shown in FIG. 5, the visual processing device 1 has gradation curves MUS0 to MUSn for converting a bright area whose input range has a value larger than about “1.0”. Based on this, the degree of compression is controlled according to the composite signal MUS. Thereby, even when a bright region signal is input to the visual processing device 1, it is possible to suppress the occurrence of insufficient gradation in the output signal.
Further, the conversion characteristic of the straight line 2 shown in FIG. 2 is set in the target level setting unit 4 so that the target level L = predetermined value T1 (fixed).
In this case, when the effect adjustment signal MOD is “0”, if the composite signal MUS = US × MOD + L × (1.0−MOD), the composite signal MUS = T1, and the composite signal is generated when the effect adjustment signal MOD is “1”. Signal MUS = unsharp signal US. By setting the target level L, one predetermined curve is selected from the curves from MUS0 to MUSn shown in FIG.

When the composite signal MUS is = T1 (fixed value), the visual processing unit 3 performs DR compression fixed by the gradation conversion curve of the curve 3 shown in FIG. In addition, when the composite signal MUS = unsharp signal US, DR compression is performed according to the brightness of the local region, so that the effect of visual processing according to the brightness of the local region is enhanced in this DR compression.
Next, the effect adjustment unit 5 adjusts the required visual processing effect by setting the effect adjustment signal MOD. For example, if MOD = 0.5, the composite signal MUS = 0.5 × US + 0.5 × T1.
In this way, by setting the effect adjustment signal MOD to a predetermined value, DR compression processing with different effects is performed by the conversion curve determined by the internal division of the gradation conversion curve of the curve 3 and the gradation conversion curve MUSn. Can be realized.

The visual processing device 1 is configured to output, as an output signal OS, a value obtained by gradation-converting the input signal IS by the visual processing unit 3, but a gain corresponding to the gradation-converted value for the input signal IS. The value may be output.
FIG. 6 is a block diagram of a visual processing device 20 that is the first modification. In order to avoid duplication, description of the same processing as the visual processing device 1 (FIG. 1) is omitted.
In FIG. 6, the visual processing device 20 is set to have a two-dimensional gradation conversion characteristic, for example, as shown in FIG. Here, the horizontal axis represents the input signal IS input, and the vertical axis represents the converted output signal OS.
As the gradation conversion characteristics, different gradation conversion curves from MUS0 to MUSn are selected according to the composite signal MUS. Due to this characteristic, the dark area in the image is converted so that the contrast becomes higher and brighter by MUS0. On the other hand, the conversion of the bright area in the image is suppressed by MUSn. Thereby, effective dark part correction can be realized for a backlight image or the like in which the face of the person is dark and the background area is bright.

Here, the visual processing unit 21 corrects the input signal IS using the gain characteristic shown in FIG. 8 with the gradient of the gradation conversion curve of FIG. 7 as a gain. The horizontal axis represents the input signal IS input, and the vertical axis represents the output of the gain signal GAIN.
By multiplying the gain signal GAIN by the input signal IS, an output equivalent to the output signal OS shown in FIG. 7 is obtained.
The target level setting unit 4 sets the conversion characteristic of the straight line 1 shown in FIG. 2 and sets the target level L = the input signal IS when realizing the gradation conversion process using the gradation conversion curve of FIG. Therefore, when the effect adjustment signal MOD = 0, the composite signal MUS = the input signal IS.
The effect adjustment unit 5 synthesizes the target level L and the unsharp signal US according to the internal division calculation according to the effect adjustment signal MOD, and outputs a synthesized signal MUS. That is, the strength of the visual processing effect can be adjusted by the effect adjustment signal MOD.

In the visual processing unit 21, when the composite signal MUS = the input signal IS, the two input signals IS input to the visual processing unit 3 and the composite signal MUS have the same value. Only the predetermined gamma conversion of the curve 5 is performed, and the gradation conversion having the effect of dark portion correction is not performed.
Thereby, by setting the value of the effect adjustment signal MOD, it is possible to adjust the effect in gradation conversion from gradation conversion based on characteristics of only a predetermined gamma conversion to gradation conversion that realizes dark portion correction.
The visual processing unit 21 outputs a gain signal GAIN based on the input signal IS and the synthesized signal MUS in order to realize the set gain characteristic.
The multiplication unit 22 multiplies the gain signal GAIN and the input signal IS and outputs an output signal OS.

As a feature of the two-dimensional gain characteristic, the change of the curve with respect to the input signal IS is more gradual than the gradation conversion curve. Therefore, even if the input signal IS and the composite signal MUS are roughly thinned out, sufficient processing accuracy can be ensured, and the bit accuracy of the input signal IS input to the visual processing unit 21 can be reduced. As a result, the circuit scale can be reduced in hardware / logic design.
The visual processing unit 21 is constituted by a two-dimensional lookup table (hereinafter referred to as “two-dimensional LUT”) that gives the relationship between the input signal IS, the composite signal MUS, and the gain signal GAIN, and the input signal IS and the composite signal MUS. In contrast, the gain signal GAIN may be output with reference to the two-dimensional LUT. Thus, storing the gain value in the two-dimensional LUT can reduce the number of bits of the two input signals and can significantly reduce the memory capacity.

Further, the visual processing unit 21 is configured by a two-dimensional LUT, so that a complicated gain characteristic can be created in advance. When the visual processing unit 21 is configured by a two-dimensional LUT, it can be realized by a read-only memory (hereinafter referred to as “ROM”) or the like. Further, in order to be able to update the gain characteristics, the two-dimensional LUT may be constituted by a rewritable memory, for example, a random access memory (hereinafter referred to as “RAM”). The two-dimensional LUT stores gain data having a preset two-dimensional gain characteristic. By changing this two-dimensional gain characteristic, various visual effects such as local contrast processing and DR compression processing can be obtained.
Further, in the visual processing devices 1 and 20, the strength of the effect can be flexibly adjusted by setting the value of the effect adjustment signal MOD with respect to the strength of the visual processing.

The effect adjustment signal MOD is a signal that can be changed in advance or in real time by setting. For example, the screen menu of the display device may be selected with a remote controller, and the corresponding value may be set as the effect adjustment signal MOD.
Further, a feature amount in an image, for example, a predetermined image pattern, image density, and color may be automatically extracted, and an optimum value may be automatically set as the effect adjustment signal MOD.
In addition, the remote control selects, for example, “movie image quality”, “news image quality”, etc. displayed on the screen selection menu of the display device, and automatically applies the value within the adjustment range preset for each selection menu. It may be semi-automatic, for example, set as the adjustment signal MOD.
Further, the visual processing devices 1 and 20 have a broadcast content detection unit (not shown), and the EPG display data separated as program information, the genre information of the currently received data, and the program description information are displayed as the broadcast content detection unit. And the effect adjustment signal MOD may be changed based on the content of the detected information. Data genre information and image information may be detected from MPEG stream information.

As described above, according to the visual processing device of this embodiment, the strength of visual processing can be increased or decreased by the effect adjustment signal MOD, so that gradation conversion characteristics and gain characteristic data corresponding to the strength are recreated. There is no need.
Thus, it is not necessary to prepare a dedicated circuit for realizing visual processing with various strengths and a profile data LUT for realizing visual processing with various strengths. Therefore, in the case of realizing the visual processing device, the memory capacity for the hardware circuit and the table can be reduced. Further, in the configuration using the LUT in the visual processing device, since it is not necessary to replace the contents of the LUT, the change time can be eliminated and the visual effect can be adjusted in real time.
Further, the visual processing device of this embodiment can be configured to change the effect adjustment signal MOD in real time, so that the strength of the effect of visual processing can be changed in real time. Specifically, the strength of visual processing can be changed in units of frames and pixels, and the strength of visual processing can be changed for a local region in an image.

In addition, the effect adjustment unit 5 generates a composite signal MUS that internally divides the input signal IS or the level signal or a preset value thereof and the unsharp signal US by the effect adjustment signal MOD. Thereby, in the visual processing device, the effect of visual processing can be changed from the characteristic of only gamma conversion for converting a predetermined brightness to the characteristic of local contrast conversion.
(Embodiment 2)
Next, a second embodiment of the present invention will be described in detail with reference to the drawings.
In general, a natural image has a large number of gradations, and by performing visual processing on the natural image, a sharp image with improved local contrast can be obtained. On the other hand, if there are steep edges in the image, side effects tend to be noticeable when visual processing is performed. If the visual processing is weakened to suppress this side effect, the processing is weakened even for a natural image, resulting in an image with no sharpness.

Therefore, by weakening the visual processing only for the vicinity of the edge, it is possible to suppress side effects in the vicinity of the edge while maintaining the processing effect for the entire natural image.
The visual processing device according to the second embodiment of the present invention outputs an effect adjustment signal for varying the effect of visual processing, and varies the effect of visual processing according to the effect adjustment signal (intensity and correction amount). ) Make adjustments.
Further, in the image to be subjected to visual processing, an area adjacent to the edge or a flat area adjacent to the edge is detected, and an effect adjustment signal is generated from the amount of edge and the degree of flatness, and the visual adjustment is performed according to the effect adjustment signal. The adjustment is made so that the effect of the treatment is different.
Thereby, even when an image having a steep edge region is input to the visual processing device, side effects in the vicinity of the edge can be suppressed while obtaining the effect of visual processing.

Here, visual processing is processing that has a characteristic close to how the human eye can see, depending on the comparison between the value of the target pixel of the input image signal and the value (brightness) of its surrounding pixels. This process determines the value of the output signal. The visual processing is applied to backlight correction, knee processing, D-range compression processing, color processing, brightness adjustment (including gradation processing and contrast adjustment), and the like.
In the embodiment of the present invention, the luminance component Y or lightness component L of the YCbCr color space, YUV color space, Lab color space, Luv color space, YIQ color space, and YPbPr color space is defined as a luminance signal. Hereinafter, the luminance signal will be described as an image signal.
A visual processing device according to Embodiment 2 of the present invention will be described with reference to FIGS. FIG. 9 is a block diagram showing the configuration of the visual processing device 101 according to Embodiment 2 of the present invention.

In FIG. 9, the visual processing device 101 according to the second embodiment of the present invention responds to the spatial processing unit 10 that outputs the peripheral image information (unsharp signal) US from the input image signal and the flatness of the edge vicinity region. A control signal generation unit 40 that outputs an effect adjustment signal MOD, an effect adjustment unit 1020 that outputs a combined signal MUS synthesized by changing the ratio of the image signal IS and the peripheral image information US according to the effect adjustment signal MOD, A visual processing unit 30 that visually processes the image signal IS based on the composite signal MUS and the image signal IS is provided.
Hereinafter, each functional unit of the visual processing device 101 will be described.
The spatial processing unit 10 extracts the value of the target pixel and the value of the pixel in the peripheral area of the target pixel (hereinafter referred to as “peripheral pixel”) from the image signal IS, and uses the extracted pixel value for the image signal IS. Filter processing for.

For example, the spatial processing unit 10 generates an unsharp signal US obtained by processing the image signal IS with a low-pass filter. The unsharp signal US is generated by the following calculation.
US = (Σ [Wij] × [Aij]) ÷ (Σ [Wij])
Here, [Wij] is the weighting factor of the pixel located in the i-th row and j-th column in the target pixel and the peripheral pixels, and [Aij] is located in the i-th row and j-th column in the target pixel and the peripheral pixels. The pixel value. Further, “Σ” means that the sum of the target pixel and the surrounding pixels is calculated.
Note that a smaller weight coefficient may be given as the absolute value of the pixel value difference is larger, or a smaller weight coefficient may be given as the distance from the target pixel is larger. The area size of the peripheral pixels is a size set in advance according to the effect, and the visual effect can be enhanced by making the size larger than a predetermined size. For example, if the size of the target image is 1024 pixels in length and 768 pixels in width, the unsharp signal US is generated from an area that is 80 pixels or more in length and width, respectively, and compared with a local area of about 3 pixels in length and width. This can enhance the visual effect.

Further, as the low-pass spatial filter, a FIR (Finite Impulse Response) type low-pass spatial filter or an IIR (Infinite Impulse Response) type low-pass spatial filter that is usually used for generating an unsharp signal may be used. .
Next, the effect adjustment unit 1020 combines the image signal IS and the unsharp signal US by interpolation processing according to the effect adjustment signal MOD output from the control signal generation unit 40, and outputs a combined signal MUS. The composite signal MUS is divided internally as shown in (Equation 1) below, for example, according to the effect adjustment signal MOD. The control signal generator 40 will be described later.
MUS = US × MOD + IS × (1.0−MOD) (Formula 1)
Here, the value of the effect adjustment signal MOD varies in the range from “0.0” to “1.0”, the value of the effect adjustment signal MOD is “0.0”, no processing is performed, and the value of the effect adjustment signal MOD. Is “1.0”, the strength of the processing is maximized. Note that (Equation 1) can be modified as in (Equation 2), and similarly, a combined signal MUS can be generated.

MUS = (US-IS) × MOD + IS (Formula 2)
Next, the visual processing unit 30 performs gradation conversion on the image signal IS according to the composite signal MUS from the effect adjustment unit 1020.
For example, the visual processing unit 30 performs gradation conversion based on the two-dimensional gradation conversion characteristics shown in FIG. Here, the two-dimensional gradation conversion refers to gradation conversion in which an output value is determined with respect to two inputs of the composite signal MUS and the image signal IS. The visual processing unit 30 outputs a processing signal OS to the image signal IS and the composite signal MUS based on the two-dimensional gradation conversion characteristics. Various visual effects can be produced by the gradation conversion characteristics.
The two-dimensional gradation conversion characteristics will be described with reference to FIG. FIG. 10 is an explanatory diagram for explaining the two-dimensional gradation conversion characteristics. Here, the horizontal axis represents the input image signal IS, and the vertical axis represents the output of the converted processing signal OS.

  As shown in FIG. 10, the two-dimensional gradation conversion has a predetermined gradation conversion characteristic according to the signal levels of the composite signals MUS0 to MUSn. Therefore, when the pixel value of the image signal IS is an 8-bit value, the pixel value of the output signal OS with respect to the value of the image signal IS divided into 256 stages is determined by a predetermined two-dimensional gradation conversion characteristic. The gradation conversion characteristic is a gradation conversion curve having a predetermined gamma conversion characteristic, and the output monotonously decreases with respect to the subscript of the composite signal MUS. Note that even if there is a portion where the output is not partly monotonically decreasing, the subscript of the composite signal MUS may be substantially monotonically decreasing. Further, as shown in FIG. 10, in the two-dimensional gradation conversion characteristics, (output value in the case of MUS = MUS0) ≧ (in the case of MUS = MUS1) with respect to the lightness values of the pixels of all the image signals IS. The relationship of output value) ≧... ≧ (output value when MUS = MUSn) is satisfied.

According to the two-dimensional gradation conversion characteristics shown in FIG. 10, the visual processing unit 30 selects MUS0 when the input image signal IS has a value “a” and the brightness value of the surrounding area is small. The value of the processing output OS is “P”. Conversely, when the brightness value of the surrounding area is large, the value of the processing output OS becomes “Q” by selecting MUSn. As described above, even if the input image signal IS has the value “a”, the processing output OS can be largely changed from the value “P” to the value “Q” by the change in the brightness value of the surrounding area. Thereby, the contrast of a dark part can be emphasized according to the synthetic | combination signal MUS.
On the other hand, if the composite signal MUS = the image signal IS in order to eliminate the effect of the visual processing, the gradation conversion characteristic of the curve 2 shown in FIG. 10 can be provided. With the tone conversion characteristics of curve 2, the brightness of the entire image can be adjusted (gamma conversion), but there is no visual effect such as increasing the contrast only in the local dark area.

By changing this two-dimensional gradation conversion characteristic, various visual processing effects can be obtained, and knee processing, DR compression processing, color processing, or brightness adjustment (gradation processing, contrast adjustment can be performed). Including).
Next, the processing output OS when the visual processing unit 30 varies the effect of visual processing based on the composite signal MUS will be described with reference to FIG. FIG. 11 is an explanatory diagram for explaining the output of the processing signal OS.
In FIG. 11A, the horizontal axis represents the pixel position to be processed, and the vertical axis represents the output of the composite signal MUS.
For example, when the value of the effect adjustment signal MOD is “0.5”, the composite signal MUS is an intermediate output between the image signal IS and the unsharp signal US.

At this time, as shown in FIG. 11B, the processing signal OS visually processed based only on the image signal IS is set to OS (IS, IS), and the visual processing based on the image signal IS and the unsharp signal US is performed. If the processing signal OS is OS (IS, US), OS (IS, MUS) which is a processing signal OS visually processed according to the image signal IS and the composite signal MUS is OS (IS, IS) and OS (IS , US).
Therefore, when the value of the effect adjustment signal MOD is “1.0”, the composite signal MUS = US, and the processing signal OS (IS, US) that has the “effect is maximum” of the visual processing is output. On the other hand, when the value of the effect adjustment signal MOD is “0.0”, the composite signal MUS = IS, and the processing signal OS (IS, IS) that is “no effect” of the visual processing is output.
As described above, the visual processing unit 30 can increase or decrease the effect of the visual processing of the dark portion contrast according to the composite signal MUS. As a result, there are various effects ranging from the effect of processing that only converts the brightness of the entire image to the effect of processing that changes (changes) the contrast in the local area according to the ambient brightness. A visual effect can be realized in the visual processing device 101.

In the visual processing device 101, knee processing, DR compression processing, color processing, and the like can be realized by changing the two-dimensional gradation conversion characteristics.
The visual processing unit 30 may have a two-dimensional LUT. In this case, the visual processing unit 30 performs gradation conversion by setting characteristic data (hereinafter referred to as “profile”) shown in FIG. 10 in the two-dimensional LUT of the visual processing unit 30.
The visual processing unit 30 may perform visual processing using an arithmetic circuit. In particular, when a profile having characteristics that can be approximated by a simple straight line is set in the two-dimensional LUT of the visual processing unit 30, the table of the two-dimensional LUT can be eliminated, and the circuit scale of the visual processing device 101 is reduced. be able to.
Next, the control signal generator 40 will be described with reference to FIGS. FIG. 12 is a block diagram showing the configuration of the control signal generator 40, and FIG. 13 is an explanatory diagram for explaining the output of the effect adjustment signal MOD.

As shown in FIG. 12, the control signal generator 40 includes an edge detector 41 that detects an edge amount that is a luminance difference for each adjacent region from the image signal IS, and an edge neighborhood that detects the degree of proximity of the edge region from the edge amount. A flatness detection unit 43 that detects the flatness of a flat region where the luminance difference between the detection unit 42 and the adjacent region is a predetermined value or less, and an effect adjustment that outputs an effect adjustment signal MOD according to the degree of edge proximity and the flatness And a signal generation unit 44.
The edge detection unit 41 detects the edge amount from the image signal IS for each region in a predetermined range. The edge detection unit 41 detects the edge amount EG using an edge detection filter (not shown) such as a primary differential filter such as a Sobel filter or a Prewitt filter, or a secondary differential filter such as a Laplacian filter. For example, when the image signal IS shown in FIG. 13A is input, the edge detection unit 41 outputs an edge amount as shown in FIG. Here, the vertical axis of FIG. 13A is the value of the image signal IS, and the horizontal axis is the pixel position of the pixel being processed. Further, the vertical axis in FIG. 13B is the edge amount EG, and the horizontal axis is the pixel position of the pixel being processed.

The edge vicinity detection unit 42 detects the vicinity area of the edge. For example, the edge vicinity detection unit 42 processes the edge amount detected for each predetermined area with a low-pass filter, and outputs a degree of proximity that becomes a large output when approaching the edge vicinity. For example, as illustrated in FIG. 13C, the edge vicinity detection unit 42 outputs an edge vicinity degree that becomes a larger output as it is closer to the edge. Here, the vertical axis in FIG. 13C is the edge proximity, and the horizontal axis is the pixel position of the pixel being processed.
The flatness detection unit 43 detects the flatness degree of the flat area where the luminance difference with the adjacent area is a predetermined value or less. For example, as shown in FIG. 13D, the flatness detection unit 43 detects a luminance difference from the adjacent region from the output of the edge amount in FIG. 13B, and outputs a larger flatness as the luminance difference is smaller. To do. Here, the vertical axis in FIG. 13D is the flatness FT indicating the flatness, and the horizontal axis is the pixel position of the pixel being processed.

As shown in FIG. 13E, the effect adjustment signal generation unit 44 multiplies the degree of proximity in FIG. 13C and the degree of flatness in FIG. An effect adjustment signal MOD that weakens the visual effect is output. Here, the vertical axis of FIG. 13D is the output of the effect adjustment signal MOD, and the horizontal axis is the pixel position of the pixel being processed. In the visual processing device 101, the visual effect becomes stronger as the value of the effect adjustment signal MOD is larger.
As a result, as shown in FIG. 13E, the effect adjustment signal generation unit 44 performs an output that weakens the visual effect in the edge vicinity region, and the visual effect is applied to a region far from the edge vicinity region. The output which strengthens is generated. Further, the effect adjustment signal generation unit 44 performs an output that weakens the visual effect as the flatness degree increases in the region near the edge according to the flatness degree, and an output that strengthens the visual effect as the flatness degree decreases. .

Thereby, the visual processing device 101 can reduce side effects only in the vicinity of the edge, and can realize visual processing having an excellent visual processing effect on a natural image.
Next, the operation of the visual processing device 101 will be described with reference to FIG. FIG. 14 is a flowchart for explaining the operation of the visual processing device 101.
As shown in FIG. 16, an image is input to the visual processing device 101 (S101), and the edge detection unit 41 detects an edge amount that is a luminance difference for each adjacent region from the image signal IS (S102).
Next, the visual processing device 101 uses the edge vicinity detection unit 42 to process the edge amount with a low-pass filter, and detects the degree of proximity from the edge amount (S103). Further, the visual processing device 101 detects the luminance difference from the edge amount by the flatness detection unit 43, and detects the flatness near the edge (S104).

Next, in the visual processing device 101, the effect adjustment signal generator 44 multiplies the proximity output from the edge proximity detector 42 by the flatness output from the flatness detector 43, and outputs the effect adjustment signal MOD. Generate (S105).
Next, the visual processing device 101 uses the effect adjustment unit 1020 to generate a synthesized signal MUS that is synthesized by changing the ratio between the image signal IS and the unsharp signal US in accordance with the effect adjustment signal MOD (S106).
Next, in the visual processing device 101, the visual processing unit 30 selects one of the curves of the two-dimensional gradation conversion characteristics shown in FIG. 10 corresponding to the composite signal MUS, and converts the image signal IS (S107). . Thereby, the visual processing device 101 executes visual processing adjusted so as to vary the effect of visual processing in accordance with the composite signal MUS.

Next, the visual processing device 101 determines whether there is a pixel to be processed next (S108). Next, when there is no pixel that needs processing, the visual processing is completed. On the other hand, if there is a pixel that needs to be processed next, the process returns to step S101, and the next image (pixel) is input. Thereafter, the steps from S101 to S108 are repeated until there are no more pixels that need to be processed.
As described above, according to the visual processing device 101 according to the second embodiment of the present invention, it is possible to reduce the side effects only in the vicinity of the edge and realize visual processing having an excellent visual processing effect on the natural image. be able to.
The visual processing device 101 obtains the edge proximity from the edge amount and the flatness from the input image signal IS, and generates the effect adjustment signal MOD based on the edge proximity and the flatness. The effect adjustment signal MOD may be generated from the amount of change in the unsharp signal US.

Hereinafter, a method for detecting a flat region near the edge according to a modification of the control signal generator 40 will be described.
An embodiment in which the effect adjustment signal MOD is generated from the amount of change in the unsharp signal US will be described with reference to FIGS. 15 and 16. FIG. 15 is a block diagram showing the configuration of the control signal generator 70.
As shown in FIG. 15, the control signal generation unit 70 includes a change amount detection unit 71 that detects a change amount of the unsharp signal US, and an effect adjustment signal generation that outputs an effect adjustment signal MOD according to the detected change amount. Part 72.
The change amount detector 71 detects the change amount of the unsharp signal US. For example, the amount of change is detected using an edge detection filter (not shown) such as a primary differential filter such as a Sobel filter or a Prewitt filter, or a secondary differential filter such as a Laplacian filter.

  The effect adjustment signal generation unit 72 adjusts the output according to the change amount detected by the change amount detection unit 71. That is, the effect adjustment signal generator 72 outputs the effect adjustment signal MOD so that the signal level (value) of the effect adjustment signal MOD decreases as the change amount increases. For example, as shown in FIG. 16, the signal level of the effect adjustment signal MOD is changed when the detected change amount is equal to or greater than a predetermined value Tha, and the signal of the effect adjustment signal MOD is within a range up to the predetermined value Thb. Decrease level. Above the predetermined value Thb, the signal level of the effect adjustment signal MOD is not changed. Thereby, the signal level of the effect adjustment signal MOD can be changed when a steep edge region is input without reacting to the edge component normally included in the natural image. Here, the horizontal axis represents the amount of change, and the vertical axis represents the output (signal level) of the effect adjustment signal MOD. Note that the range of the signal level of the output effect adjustment signal MOD is changed from “0.0” to “1.0”, but from “0.2” to “1.0” depending on the intensity of visual processing. You may make it adjust. Further, the visual processing device 101 is configured so that the effect of the visual processing in the visual processing device 101 becomes stronger as the signal level of the effect adjustment signal MOD is higher.

As described above, according to the control signal generator 70, the flat region near the edge can be detected from the amount of change in the unsharp signal US, and the effect adjustment signal MOD can be generated.
Note that a flat region near the edge is detected from a reduced image such as a thumbnail image in which the image signal is reduced, and an effect adjustment signal MOD is output based on the degree of flatness near the edge or the amount of change in the unsharp signal US. You may do it.
Further, a reduction processing unit (not shown) for reducing the image signal is provided between the image signal and the control signal generation unit 40, and the flatness degree near the edge or unsharpness from the reduced image generated by the reduction processing unit. The effect adjustment signal MOD may be output based on the change amount of the signal US.
By using the reduced image, it is possible to detect a flat region near the edge while suppressing the influence of noise. In other words, the reduced image generated by the reduction method that thins out after averaging the image signal has a reduced noise component, so that the reduced image is used to detect a flat region near the edge while suppressing the influence of noise. be able to. If a reduced image is used, the number of pixels to be detected can be reduced and the amount of calculation can be reduced.

In addition, a low-pass filter or the like may be installed in front of the control signal generation unit 40 and the control signal generation unit 70 to limit the band of the image signal and detect a flat region near the edge. Thereby, the noise component can be reduced, and a flat region near the edge can be detected while suppressing the influence of noise.
(Embodiment 3)
In the second embodiment of the present invention, the composite signal MUS synthesized by changing the ratio of the image signal IS and the peripheral image information (unsharp signal) US according to the effect adjustment signal MOD is output, and the visual processing unit 30 has an effect. Although the processing output OS obtained by visually processing the image signal IS according to the composite signal MUS from the adjustment unit 1020 is output, in the third embodiment of the present invention, the processing output OS visually processed by the effect adjustment unit 1021. An embodiment in which a combined output OUT obtained by combining the image signal IS and the image signal IS in accordance with the effect adjustment signal will be described with reference to FIG.

FIG. 17 is a block diagram showing a configuration of the visual processing device 102 according to Embodiment 3 of the present invention.
Hereinafter, parts similar to those of the second embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
In FIG. 17, the visual processing unit 30 outputs a processing output OS based on the image signal IS and the output US of the spatial processing unit 10.
The effect adjustment unit 1021 performs an internal calculation on the image signal IS and the processing output OS according to the effect adjustment signal MOD, thereby changing (changing) the effect of visual processing. For example, the output OUT from the effect adjustment unit 1021 is calculated by internal division calculation as shown in the following (Equation 3).
OUT = OS × MOD + IS × (1.0−MOD) (Formula 3)
(Equation 3) can also be realized by modifying it as (Equation 4).

OUT = (OS−IS) × MOD + IS (Formula 4)
As described above, according to the third embodiment of the present invention, the synthesized signal OUT synthesized by changing the ratio of the processed signal OS and the image signal IS in accordance with the effect adjustment signal MOD can be output. The effect can be changed (changed).
The control signal generator 40 may be replaced with the control signal generator 70 in the second embodiment of the present invention. Also in this manner, the edge vicinity region can be detected in the same manner, and the effect adjustment signal MOD corresponding to the amount of change in the peripheral information in the vicinity of the edge can be generated.
(Embodiment 4)
In the second embodiment of the present invention, a composite signal MUS synthesized by changing the ratio of the image signal IS and the peripheral image information US according to the effect adjustment signal MOD is output, and the visual processing unit 30 receives the signal from the effect adjustment unit 1020. Although the processing output OS obtained by visually processing the image signal according to the composite signal MUS is output, in the fourth embodiment of the present invention, the effect adjustment unit 1022 determines the effect of the visual processing according to the effect adjustment signal MOD. An embodiment in which the synthesized output OUT synthesized by changing the ratio of the outputs of the different visual processing units 31 and 32 will be described with reference to FIG.

FIG. 18 is a block diagram showing a configuration of the visual processing device 103 according to Embodiment 4 of the present invention. Hereinafter, parts similar to those of the second embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
The effect adjustment unit 1022 outputs the output OSA of the visual processing unit 31 in which the first profile 60 having different visual processing intensity is set in the LUT according to the effect adjustment signal MOD output from the control signal generation unit 40, and the second OSA. The output 61 of the visual processing unit 32 in which the profile 61 is set to the LUT is synthesized by internal calculation, and a synthesized output OUT is output. Note that a composite output may be generated by external division calculation. At this time, the composite output OUT is as shown in (Formula 5).
OUT = OSA × MOD + OSB × (1.0−MOD) (Formula 5)
Note that (Equation 5) can also be realized by modifying it as (Equation 6).

OUT = (OSA−OSB) × MOD + OSB (Formula 6)
As described above, according to the visual processing device 103 according to the fourth embodiment of the present invention, the output of the visual processing unit 31 and the output of the visual processing unit 32 having different visual processing effects according to the effect adjustment signal MOD. Visual processing with different degrees of visual effect can be performed by obtaining a composite output synthesized by changing the ratio.
The control signal generator 40 may be replaced with the control signal generator 70 in the second embodiment of the present invention. Also in this manner, the edge vicinity region can be detected in the same manner, and the effect adjustment signal MOD corresponding to the amount of change in the peripheral information in the vicinity of the edge can be generated.
(Embodiment 5)
In the visual processing devices according to the second embodiment to the fourth embodiment of the present invention, tone conversion values based on the two-dimensional tone conversion characteristics are output, but the fifth embodiment of the present invention. Now, a case where gradation conversion is performed using a gain signal will be described with reference to FIGS.

FIG. 19 is a block diagram showing a configuration of the gain-type visual processing system 104 according to the fifth embodiment of the present invention, and FIG. 20 is an explanatory diagram for explaining a two-dimensional gain characteristic. Hereinafter, parts similar to those of the second embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
In FIG. 19, the gain-type visual processing system 104 includes a gain-type visual processing device 1905 that outputs a gain signal GAIN obtained by visually processing the image signal IS, and a multiplier 1911 that multiplies the gain signal GAIN and the image signal IS. ing.
The gain-type visual processing device 1905 includes a visual processing device 101 that outputs a processed signal OS obtained by visually processing the image signal IS, and a divider 1912 that divides the processed signal OS by the image signal IS. Here, the visual processing device 101 outputs a gradation conversion value obtained by visually processing the output of the image signal IS, and the gain-type visual processing device 5 is divided by dividing the gradation conversion value by the image signal IS. realizable.

The multiplier 1911 multiplies the gain signal GAIN output from the gain-type visual processing device 1905 and the image signal IS, and outputs a gradation conversion value obtained by visually processing the output of the image signal IS.
Note that the visual processing unit 30 may directly use the profile having the two-dimensional gain characteristic shown in FIG. Here, the vertical axis of FIG. 20 is the gain output GN, and the horizontal axis is the image signal IS. The two-dimensional gain characteristic shown in FIG. 20 is equivalent to the one obtained by dividing the output of the two-dimensional gradation characteristic profile shown in FIG. 10 by the image signal IS. A profile having this two-dimensional gain characteristic may be set in the LUT of the visual processing unit 30 of the visual processing device 101. As described above, if the profile of the two-dimensional gain characteristic is set in advance in the LUT of the visual processing unit 30, the gain signal GN and the gain signal GAIN are equivalent. Can be realized.

In the gain-type visual processing device 1905, since the change in the processing signal is small with respect to the change in the input image signal IS, the number of bits of the input signal can be reduced and the circuit scale can be reduced. Further, when the visual processing unit 30 is provided with a two-dimensional LUT, the memory capacity can be reduced.
As described above, according to the gain-type visual processing system 104 of Embodiment 5 of the present invention, by controlling the gain signal GAIN, it is possible to easily suppress gradation saturation and realize excellent visual processing. can do.
The visual processing device 101 according to the second embodiment of the present invention may be replaced with the visual processing device 102 according to the third embodiment of the present invention. In this way, the gain-type visual processing device 1905 can be similarly realized.
The visual processing device 101 according to the second embodiment of the present invention may be replaced with the visual processing device 103 according to the fourth embodiment of the present invention. In this way, the gain-type visual processing device 1905 can be similarly realized.

As described above, according to Embodiment 2 to Embodiment 5 of the present invention, even when an image having a steep edge region is input, visual processing with reduced side effects is realized. be able to.
Note that the visual processing device described in the above embodiment may be built in or connected to a device that handles moving images, and the effect adjustment signal MOD may be generated from an image for each frame or field. When the image signal is a frame image, the control signal generation unit 40 detects edge information and flatness from one (1 frame) or more previous frame image, or when the image signal is a field image, from one (1 field) or more previous field image. Information can be extracted. Thereby, the visual processing device can use the effect adjustment signal MOD corresponding to the edge information and the flatness information from the head of the frame. Further, the visual processing device can extract edge information and flatness information from the previous (one field previous) field image, and uses an effect adjustment signal MOD corresponding to the edge information and flatness information from the head of the field image. Can do. Further, the control signal generator 40 extracts the edge information and the flatness information from one or more previous (one frame) previous frame images or one (one field) or more previous field images, thereby reducing the circuit delay. It is easy to match, and the circuit scale can be reduced.

(Embodiment 6)
Generally, a natural image has a large number of gradations, and by performing visual processing on the natural image, it is possible to obtain a sharp image in which the local contrast ratio is emphasized. On the other hand, the special image has a statistical information bias such that the ratio of the area where the shading changes in the image of the image signal is extremely small, or the ratio of the area where the shading does not change in the image of the image signal is extremely large. Have. In such a special image, there are many flat regions in the image. For this reason, when visual processing is performed on a special image having sharp edges, side effects are easily noticeable. If the visual processing is weakened to suppress this side effect, the processing is weakened even for a natural image, resulting in an unsharp image.
Therefore, by suppressing the side effects only on the special image, it is possible to realize an excellent visual processing effect on the natural image.

The visual processing device according to the sixth embodiment of the present invention detects a special image having a statistical information bias from the image signal, generates an effect adjustment signal based on the degree of the statistical information bias, and generates the effect adjustment signal. The visual processing effect is adjusted to be changed (changed) according to the effect adjustment signal.
Here, visual processing is processing that has a characteristic close to how the human eye can see, depending on the comparison between the value of the target pixel of the input image signal and the value (brightness) of its surrounding pixels. This process determines the value of the output signal. The visual processing is applied to backlight correction, knee processing, D-range compression processing, color processing, brightness adjustment (including gradation processing and contrast adjustment), and the like.
In the embodiment of the present invention, the luminance component Y or lightness component L of the YCbCr color space, YUV color space, Lab color space, Luv color space, YIQ color space, and YPbPr color space is defined as a luminance signal. Hereinafter, the luminance signal will be described as an image signal.

A visual processing device according to Embodiment 6 of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram showing a configuration of a visual processing device 1001 according to Embodiment 6 of the present invention.
In FIG. 21, the visual processing device 1001 according to the sixth embodiment of the present invention includes a spatial processing unit 10 that extracts peripheral image information (unsharp signal) US from an input image signal IS and a statistical signal from the image signal IS. A special image detecting unit 2140 that detects a special image having information bias and outputs a special image effect adjustment signal DS for differentiating the effect of visual processing based on the degree of statistical information bias; A continuous change processing unit 50 that outputs an effect adjustment signal MOD in which the effect adjustment signal DS is continuously changed between frames, and the ratio between the image signal IS and the peripheral image information US is changed according to the effect adjustment signal MOD. An effect adjustment unit 1020 that outputs a synthesized signal MUS, and a processing output that visually processes the image signal IS in accordance with the synthesized signal MUS from the effect adjustment unit 1020. And a visual processing portion 30 for outputting the OS.

With this configuration, the special image detection unit 2140 can output the special image effect adjustment signal DS corresponding to the degree of information bias of the special image. Further, the effect adjustment unit 1020 can generate a composite signal MUS for differentiating the effect of visual processing in the visual processing unit 30 based on the effect adjustment signal MOD obtained by continuously changing the special image effect adjustment signal DS. Further, the visual processing unit 30 can perform gradation conversion on the image signal IS in accordance with the composite signal MUS output from the effect adjustment unit 1020.
As a result, even when a special image is input, the visual processing device 1001 can detect the special image, and the visual processing unit 30 can change the effect of the visual processing on the special image and suppress side effects. .
Hereinafter, each functional unit of the visual processing device 1001 will be described.

The spatial processing unit 10 extracts the value of the target pixel and the value of the pixel in the peripheral area of the target pixel (hereinafter referred to as “peripheral pixel”) from the image signal IS, and uses the extracted pixel value to output the image signal. Filter the IS.
For example, the unsharp signal US is generated from the image signal IS by processing the image signal IS with a low-pass filter. The unsharp signal US is generated by the following calculation.
US = (Σ [Wij] × [Aij]) / (Σ [Wij])
Here, [Wij] is the weighting factor of the pixel located in the i-th row and j-th column in the target pixel and the peripheral pixels, and [Aij] is located in the i-th row and j-th column in the target pixel and the peripheral pixels. The pixel value. Further, “Σ” means that the sum of the target pixel and the surrounding pixels is calculated.

Note that a smaller weight coefficient may be given as the absolute value of the pixel value difference is larger, or a smaller weight coefficient may be given as the distance from the target pixel is larger. The area size of the peripheral pixels is a size set in advance according to the effect, and the visual effect can be enhanced by making the size larger than a predetermined size. For example, if the size of the target image is 1024 pixels in length and 768 pixels in width, the unsharp signal US is generated from an area that is 80 pixels or more in length and width, respectively, and compared with a local area of about 3 pixels in length and width. This can enhance the visual effect.
Further, as the low-pass filter, an FIR (Finite Impulse Response) type spatial filter, an IIR (Infinite Impulse Response) type spatial filter, or the like may be used.

Next, the effect adjustment unit 1020 combines the image signal IS and the unsharp signal US by interpolation processing according to the effect adjustment signal MOD output from the continuous change processing unit 50, and outputs a combined signal MUS. The composite signal MUS is internally divided as shown in the following (Equation 7), for example, according to the effect adjustment signal MOD. The continuous change processing unit 50 will be described later.
MUS = US × MOD + IS × (1.0−MOD) (Formula 7)
Here, the value of the effect adjustment signal MOD changes in the range from “0.0” to “1.0”, the value of the effect adjustment signal MOD is “0.0”, and there is no visual processing effect. The effect of visual processing is maximized when the MOD value is “1.0”. Note that (Equation 7) can be modified as in (Equation 8), and similarly, a composite signal MUS can be generated.
MUS = (US-IS) × MOD + IS (Formula 8)
Next, the visual processing unit 30 performs gradation conversion on the image signal IS according to the composite signal MUS from the effect adjustment unit 1020.

The visual processing unit 30 performs gradation conversion based on, for example, the two-dimensional gradation conversion characteristic shown in FIG. Here, the two-dimensional gradation conversion refers to gradation conversion in which an output value is determined with respect to two inputs of the composite signal MUS and the image signal IS. The visual processing unit 30 outputs a processing signal OS to the image signal IS and the composite signal MUS based on the two-dimensional gradation conversion characteristics. Various visual effects can be produced by the gradation conversion characteristics.
The two-dimensional gradation conversion characteristics will be described with reference to FIG. FIG. 22 is an explanatory diagram for explaining the two-dimensional gradation conversion characteristics. Here, the horizontal axis represents the input image signal IS, and the vertical axis represents the output of the converted processing signal OS.
As shown in FIG. 22, the two-dimensional gradation conversion has a predetermined gradation conversion characteristic according to the signal levels of the composite signals MUS0 to MUSn. Therefore, when the pixel value of the image signal IS is an 8-bit value, the pixel value of the output signal OS with respect to the value of the image signal IS divided into 256 stages is determined by a predetermined two-dimensional gradation conversion characteristic. The gradation conversion characteristic is a gradation conversion curve having a predetermined gamma conversion characteristic, and the output monotonously decreases with respect to the subscript of the composite signal MUS. Note that even if there is a portion where the output is not partly monotonically decreasing, the subscript of the composite signal MUS may be substantially monotonically decreasing. Further, as shown in FIG. 22, in the two-dimensional gradation conversion characteristics, (output value when MUS = MUS0) ≧ (output value when MUS = MUS1) with respect to the brightness value of all image signals IS ) ≧... ≧ (output value when MUS = MUSn) is satisfied.

According to the two-dimensional gradation conversion characteristic shown in FIG. 22, the visual processing unit 30 selects MUS0 when the brightness value of the surrounding area is small with respect to the value “a” of the input image signal IS. The value of the processing output OS is “P”. Conversely, when the brightness value of the surrounding area is large, the value of the processing output OS becomes “Q” by selecting MUSn. As described above, even if the input image signal IS has the value “a”, the processing output OS can be largely changed from the value “P” to the value “Q” by the change in the brightness value of the surrounding area. Thereby, the contrast of a dark part can be emphasized according to the synthetic | combination signal MUS.
On the other hand, in order to eliminate the effect of visual processing, if the composite signal MUS = image signal IS, the tone conversion characteristic of curve 2 shown in FIG. 22 can be provided. The gradation conversion characteristic of curve 2 can adjust the brightness of the entire image (gamma conversion), but has no visual effect such as increasing local contrast.

By changing this two-dimensional gradation conversion characteristic, various visual processing effects can be obtained, and knee processing, DR compression processing, color processing, or brightness adjustment (gradation processing, contrast adjustment can be performed). Including).
Next, the processing output OS when the visual processing unit 30 varies the effect of visual processing based on the composite signal MUS will be described with reference to FIG. FIG. 23 is an explanatory diagram for explaining the output of the processing signal OS.
In FIG. 23A, the horizontal axis represents the pixel position to be processed, and the vertical axis represents the output of the composite signal MUS.
For example, when the value of the effect adjustment signal MOD is “0.5”, the composite signal MUS is an intermediate output between the image signal IS and the unsharp signal US.

At this time, as shown in FIG. 23B, the processing signal OS visually processed based only on the image signal IS is set to OS (IS, IS), and the visual processing based on the image signal IS and the unsharp signal US is performed. If the processing signal OS is OS (IS, US), OS (IS, MUS) which is a processing signal OS visually processed according to the image signal IS and the composite signal MUS is OS (IS, IS) and OS (IS , US).
Therefore, when the value of the effect adjustment signal MOD is “1.0”, the composite signal MUS = US, and the processing signal OS (IS, US) that has the “effect is maximum” of the visual processing is output. On the other hand, when the value of the effect adjustment signal MOD is “0.0”, the composite signal MUS = IS, and the processing signal OS (IS, IS) that is “no effect” of the visual processing is output.
As described above, the visual processing unit 30 can increase or decrease the local contrast enhancement effect according to the composite signal MUS. As a result, there are various effects ranging from the effect of processing that only converts the brightness of the entire image to the effect of processing that changes (changes) the contrast in the local area according to the ambient brightness. A visual effect can be realized in the visual processing device 1001.

In the visual processing device 1001, knee processing, DR compression processing, color processing, and the like can be realized by changing the two-dimensional gradation conversion characteristics.
The visual processing unit 30 may have a two-dimensional LUT. In this case, the visual processing unit 30 performs gradation conversion by setting characteristic data (hereinafter referred to as “profile”) shown in FIG. 22 in the two-dimensional LUT.
The visual processing unit 30 may perform visual processing using an arithmetic circuit. In particular, when a profile having characteristics that can be approximated by a simple straight line is set in the two-dimensional LUT of the visual processing unit 30, the table of the two-dimensional LUT can be eliminated, and the circuit scale of the visual processing device 1001 is reduced. be able to.
Next, the special image detection unit 2140 will be described with reference to FIGS. 24, 25, 26, and 27. Here, a case will be described in which the information bias of the special image is detected from the ratio of the region where the shading changes in the image. Also, the change in shading is detected from the edge component.

24 is a block diagram showing the configuration of the special image detection unit 2140, FIG. 25 is an explanatory diagram for explaining the special image, FIG. 26 is an explanatory diagram for explaining the edge pixel, and FIG. 27 is a special image effect adjustment. It is explanatory drawing for demonstrating the output of signal DS.
As shown in FIG. 24, the special image detection unit 2140 includes an edge detection unit 2141 that detects an edge amount for each pixel from the image signal IS, and an edge amount determination unit that determines an edge pixel whose edge amount is a predetermined value or more. 2142, an edge density calculation unit 2143 that calculates the ratio of the number of edge pixels to the total number of pixels of the image signal IS, and an effect of outputting the special image effect adjustment signal DS according to the ratio calculated by the edge density calculation unit 2143 And an adjustment signal generator 2144.
Thereby, in the visual processing device 1001, a special image in which the number of gradation levels is extremely small and the edge component is limited to the contour region of the drawn image can be detected, and the deviation of the information can be detected.

Further, the special image detection unit 2140 detects a statistical information bias from the frame image one frame or more before when the image signal is a frame image, and the field image one field or more before when the image signal is a field image. To detect statistical information bias. Thereby, the visual processing device 1001 can use the special image effect adjustment signal DS corresponding to the bias of the special image information from the head of the frame or field.
For example, a case where the special image detection unit 2140 processes the special image 200 shown in FIG. 25 will be described. As shown in FIG. 25, the special image 200 includes a background area 201, a pattern group 202, a pattern group 203, and a pattern group 204, and the density values are constant or small in all areas. Each group is different in shape but has almost the same gray value.

The edge detection unit 2141 detects the edge amount for each pixel from the image signal IS. The edge detection unit 2141 detects an edge amount by using an edge detection filter (not shown) such as a primary differential filter such as a Sobel filter or a Prewitt filter, or a secondary differential filter such as a Laplacian filter.
The edge amount determination unit 2142 compares a preset threshold value and the edge amount for each pixel, and determines that the pixel is an edge pixel when the edge amount is equal to or greater than a predetermined threshold value.
For example, by processing the special image 200 by the edge amount determination unit 2142, an output 300 as shown in FIG. 26 is obtained.
In FIG. 26, the edge pixels are the edge pixel 301, the edge pixel 302, and the edge pixel 303, and are generated in the contour area of the graphic pattern of the special image 200.

Next, returning to FIG. 24, the edge density calculation unit 2143 calculates an edge density, which is a ratio of the number of edge pixels to the total number of pixels of the image signal IS, as follows.
Edge density = number of edge pixels / total number of pixels Here, if the image signal IS is a frame image, the edge density is a ratio of the number of edge pixels to all pixels in the frame. If the image signal IS is a field image, the ratio is the number of edge pixels with respect to all pixels in the field.
The effect adjustment signal generator 2144 adjusts the output according to the edge density. That is, the effect adjustment signal generation unit 2144 outputs the signal level (value) of the special image effect adjustment signal DS as the edge density increases. For example, as shown in FIG. 27, the signal level of the special image effect adjustment signal DS is increased in the range where the edge density is greater than or equal to a predetermined value Tha to a predetermined value Thb. By providing the threshold value in this way, it is possible to generate the special image effect adjustment signal DS in which the visual effect is completely eliminated when the threshold value is less than the threshold value “Tha” including the special image. On the other hand, when the threshold value is “Yhb” or more including a normal image that is not a special image, the special image effect adjustment signal DS for processing without reducing the visual effect can be generated. Here, the horizontal axis represents the edge density, and the vertical axis represents the output of the special image effect adjustment signal DS. The signal level range of the special image effect adjustment signal DS to be output is set from “0.0” to “1.0”, but “0.2” to “1.0” depending on the intensity of visual processing. Or the like. Further, the visual processing device 1001 is configured so that the effect of visual processing becomes stronger as the signal level of the special image effect adjustment signal DS is larger.

  The continuous change processing unit 50 is continuous between frames when the special image effect adjustment signal DS is output in units of frames, or between fields when the special image effect adjustment signal DS is output in units of fields. It operates to change the effect adjustment signal MOD. For example, the continuous change processing unit 50 includes a storage unit (not shown) such as a register that temporarily stores the special image effect adjustment signal DS, and the special image effect output from the special image detection unit 2140 in a new frame. The adjustment signal DS and the special image effect adjustment signal DS temporarily stored are internally divided to generate an effect adjustment signal MOD, and the generated effect adjustment signal MOD is stored in the storage unit. The storage unit stores the special image effect adjustment signal DS detected first as an initial value. The continuous change processing unit 50 outputs the effect adjustment signal MOD generated by this internal division calculation. Thus, the effect adjustment signal MOD is prevented from changing abruptly between frames. The continuous change processing unit 50 can be realized by an IIR filter or the like.

Next, the operation of the visual processing device 1001 will be described with reference to FIG. FIG. 28A is a flowchart for explaining the operation of the visual processing device 1001. FIG. 28B is a diagram illustrating an example of the configuration of the continuous change processing unit 50.
As shown in FIGS. 28A and 28B, when the image signal IS is a frame image, a plurality of frame images are visually detected in order to detect statistical information bias from the frame image one frame or more before. Input to the processing apparatus 1001. Alternatively, when the image signal IS is a field image, a plurality of field images are input to the visual processing device 1001 in order to detect statistical information bias from the field image one field or more before (S201). After a plurality of frame images or a plurality of field images are input to the visual processing device 1001, the special image detection unit 2140 detects a special image from the image signal IS which is a frame image or a field image to be detected, and detects it. The special image effect adjustment signal DS corresponding to the statistical bias of the special image is output (S202).

Next, the visual processing device 1001 performs an interpolation process so that the effect adjustment signal MOD continuously changes between frames. The visual processing device 1001 reads the effect adjustment signal MOD1 one frame before temporarily stored in the storage unit 5001 such as a register for temporary storage by the continuous change processing unit 50 (S203), and the special image effect detected in step S202. The adjustment signal DS and the effect adjustment signal MOD1 read out in step S203 are interpolated by internal division calculation or the like, and the effect adjustment signal MOD generated by the interpolation processing is output from the continuous change processing unit 50 (S204). Thereby, it is possible to suppress an abrupt change that occurs between processed frame images, and to suppress flickering of an image caused by a difference in visual effect.
Next, the visual processing device 1001 temporarily stores the effect adjustment signal MOD generated by interpolating the special image effect adjustment signal DS and the effect adjustment signal MOD1 in the storage unit 5001 (S205). When this interpolation processing is based on internal division calculation, the internal ratio is given in advance.

Next, in the visual processing device 1001, the effect adjustment unit 1020 generates a composite signal MUS by combining the image signal IS and the unsharp signal US from the spatial processing unit 10 according to the effect adjustment signal MOD (S206).
The visual processing device 1001 uses the visual processing unit 30 to select one of the two-dimensional gradation conversion characteristic curves shown in FIG. 22 according to the composite signal MUS, and converts the image signal IS (S207).
Next, the visual processing device 1001 determines whether there is a frame image to be processed next (S208). If there is no frame image that needs to be processed next, the visual processing is completed. On the other hand, if there is a frame image that needs to be processed next, the process returns to step S201 to input the next frame image. Thereafter, the steps from S201 to S208 are repeatedly executed until there is no frame that needs to be processed.

Although the case where the interpolation process is performed so that the effect adjustment signal MOD continuously changes between frames has been described above, the object of the interpolation process is not limited to between frames but may be between fields.
As described above, according to the visual processing device 1001 of the sixth embodiment of the present invention, even when a special image is input, an edge in the image is detected, and visual detection is performed based on the detected edge amount. Since the processing effect is adjusted, the side effect can be suppressed in the special image while the visual effect is enhanced in the natural image.
Note that the method of detecting the statistical bias is not limited to the method of the special image detection unit 2140 described above. The special image has a statistical information bias such that the ratio of the area where the shading changes in the image of the image signal IS is extremely small, or the ratio of the area where the shading does not change in the image of the image signal IS is extremely large. It has.

Hereinafter, other modified examples of the method for detecting the statistical bias will be described.
First, the special image detection unit 700 according to the first modification will be described. The special image detection unit 700 according to the first modification detects a statistical information bias from the ratio of regions in which the shading does not change in the image of the image signal IS. The region where the density does not change can be detected based on the flatness of the image. As a method of detecting the flatness, a method of detecting a deviation in the number of gradations from the image signal IS is employed. In an image in which the number of gradation levels (number of gradations) that can be taken by each pixel constituting the image is extremely small (an image in which the distribution of the number of gradation levels taken by each pixel is extremely narrow), the region where the density is constant is wide. Therefore, the degree of flatness in the image increases. The degree of the special image can be obtained from this information bias.
A first modification in the case of detecting a deviation in the number of gradations from the image signal IS will be described with reference to FIGS. 29 is a block diagram illustrating a configuration of the special image detection unit 700 according to the first modification, FIG. 30 is an explanatory diagram for explaining the frequency distribution detected by the frequency detection unit 701 according to the first modification, and FIG. It is explanatory drawing for demonstrating the special image effect adjustment signal DS output from the special image detection part 700 of FIG.

As shown in FIG. 29, the special image detecting unit 700 compares the frequency for each gradation level with a predetermined threshold, and the frequency detecting unit 701 for detecting the frequency for each gradation level from the image signal. In the frequency determination unit 702 that determines a gradation level having a higher frequency, the gradation number detection unit 703 that detects the number of gradation levels determined to be higher by the frequency determination unit 702, and the gradation number detection unit 703 And an effect adjustment signal generator 704 that outputs an effect adjustment signal according to the detected number of gradation levels.
The frequency detection unit 701 detects the frequency for each gradation level from the image signal by the histogram method. For example, if the image signal is 256 gradations, the appearance frequency of each gradation level from “0” to “255” is detected.
The frequency determination unit 702 compares the frequency for each gradation level with a predetermined threshold value, and detects a gradation level with a frequency greater than the predetermined threshold value.

As illustrated in FIG. 30, the frequency determination unit 702 determines that the frequency 401 is greater than a predetermined threshold Th at the gradation level La. Similarly, the frequency determination unit 702 determines that the frequency 402, the frequency 403, and the frequency 400 are larger than the predetermined threshold Th at the gradation level Lb, the gradation level Lc, and the gradation level Ld. Here, the horizontal axis in FIG. 30 is the gradation level, and the vertical axis is the frequency.
The gradation number detection unit 703 counts the number of gradation levels determined by the frequency determination unit 702 as having a high frequency.
The effect adjustment signal generator 704 increases the signal level (value) of the special image effect adjustment signal DS as the number of gradations increases in accordance with the counted number of gradation levels, thereby adjusting the special image effect adjustment. The signal DS is output. For example, as shown in FIG. 31, the signal level (value) of the special image effect adjustment signal DS is increased in a range where the counted number of gradation levels is greater than or equal to a predetermined value Thc to a predetermined value Thd.

By providing the threshold value in this way, the effect adjustment signal generation unit 704 can generate the special image effect adjustment signal DS that completely eliminates the visual effect when the threshold value is “Thc” or less including the special image. On the other hand, the effect adjustment signal generation unit 704 can generate a special image effect adjustment signal DS for processing without degrading the visual effect when the threshold value “Thd” is greater than or equal to a normal image that is not a special image. In FIG. 31, the horizontal axis represents the number of gradation levels, and the vertical axis represents the output of the special image effect adjustment signal DS. Note that the range of the value of the special image effect adjustment signal DS to be output is set from “0.0” to “1.0”, but “0.2” to “1.0” depending on the intensity of visual processing. You may make it adjust to. Further, the visual processing device 1001 is configured so that the effect of the visual processing becomes stronger as the value of the special image effect adjustment signal DS is larger.
As described above, according to the special image detection unit 700 of the first modification, the degree of the special image can be detected from the image signal according to the bias of the image information, and the special image detection unit 2140 is replaced with the special image detection unit 700. Is possible.

Next, the special image detection unit 80 according to the second modification will be described. The special image detection unit 80 according to the modification 2 detects the statistical information bias from the ratio of the region in which the shading does not change in the image of the image signal IS. The region where the density does not change can be detected based on the flatness of the image. As a method of detecting the flatness, an average obtained by detecting a continuous length in which similar pixels having a luminance difference with an adjacent pixel equal to or smaller than a predetermined value from the image signal IS is detected and averaging a plurality of detected continuous lengths. A method for detecting the continuous length is adopted. Thereby, the degree of the special image can be detected. In a special image, since the region where the density is constant is wide, the degree of flatness in the image is high, and many pixels having similar luminance are continuous. That is, the degree of the special image can be detected from the statistical information bias.
The case of the modification 2 which detects the continuous length when the similar brightness | luminance signal continues from an image signal is demonstrated using FIG.32, FIG.33 and FIG.34.

FIG. 32 is a block diagram showing the configuration of the special image detection unit 80 of the second modification, FIG. 33 is an explanatory diagram for explaining the continuous length of the second modification, and FIG. 34 is a special image effect adjustment signal DS of the second modification. It is explanatory drawing for demonstrating.
As shown in FIG. 32, the special image detection unit 80 according to the second modification includes a similar luminance detection unit 81 that detects a similar pixel in which the luminance difference between adjacent pixels is equal to or less than a predetermined value from the image signal IS, and A continuous length detecting unit 82 for detecting continuous continuous lengths, an average continuous length calculating unit 83 for calculating an average continuous length by averaging a plurality of continuous lengths detected by the continuous length detecting unit 82, and an average continuous And an effect adjustment signal generator 84 for outputting a special image effect adjustment signal DS according to the length.
The similar luminance detection unit 81 detects a similar pixel in which the luminance difference with an adjacent pixel is a predetermined value or less from the image signal. The predetermined value is a value that is experimentally determined in advance, and is determined by the required image quality specification of the device.

The continuous length detection unit 82 detects a continuous length in which similar pixels are continuous. For example, as shown in FIG. 33, similar pixels are continuously arranged in the vertical direction such as the vertical direction 503, the vertical direction 504, and the vertical direction 505, and in the horizontal direction such as the horizontal direction 500, the horizontal direction 501, and the horizontal direction 502. The number of existing pixels is detected as a continuous length.
The average continuous length calculator 83 calculates an average continuous length by averaging a plurality of continuous lengths detected by the continuous length detector 82.
The effect adjustment signal generator 84 outputs the signal level (value) of the special image effect adjustment signal DS to be smaller as the average continuous length is longer in accordance with the average continuous length. For example, as shown in FIG. 34, the signal level (value) of the special image effect adjustment signal DS is decreased in a range where the detected average continuous length is greater than or equal to a predetermined value “The” to a predetermined value “Thf”. . Here, the horizontal axis represents the average continuous length, and the vertical axis represents the output of the special image effect adjustment signal DS.

By providing the threshold value in this way, the effect adjustment signal generation unit 84 performs a special image effect adjustment signal for processing without reducing the visual effect when the threshold value “The” is equal to or less than the threshold value “The” including a normal image that is not a special image. DS can be generated. On the other hand, the effect adjustment signal generation unit 84 can generate the special image effect adjustment signal DS in which the visual effect is completely eliminated when the threshold is “Thf” or more including the special image.
Note that the range of the value of the special image effect adjustment signal DS to be output is set from “0.0” to “1.0”, but “0.2” to “1.0” depending on the intensity of visual processing. You may make it adjust to. Further, the visual processing device 1001 is configured so that the effect of the visual processing becomes stronger as the value of the special image effect adjustment signal DS is larger.
As described above, according to the special image detection unit 80 of the second modification, the degree of the special image having the bias of the image information can be detected from the image signal, and the special image detection unit 2140 can be replaced with the special image detection unit 80. It becomes possible.

Next, a special image detection unit 90 according to Modification 3 will be described. In the third modification, the statistical information bias is detected from the ratio of the region where the shading changes in the image of the image signal IS. The region where the density changes can be detected by the edge component in the image. Here, a special image is obtained by detecting a high-frequency block including a high-frequency component from a plurality of divided blocks as an edge component in the image, and detecting a ratio of the number of high-frequency blocks to the total number of divided blocks. Detect the degree.
The case of the modification 3 which detects the ratio of the number of high frequency blocks is demonstrated using FIG.35, FIG.36 and FIG.37. FIG. 35 is a block diagram showing the configuration of the special image detection unit 90 of the third modification, FIG. 36 is an explanatory diagram for explaining a block image of the third modification, and FIG. 37 is a special image effect adjustment signal DS of the third modification. It is explanatory drawing for demonstrating.

As shown in FIG. 35, the special image detection unit 90 of the third modification includes a high frequency block detection unit 91 that detects a high frequency block including a high frequency component from an image signal IS divided into a plurality of blocks, and a high frequency for the total number of blocks. A high-frequency block density detection unit 92 that detects a ratio of the number of blocks and an effect adjustment signal generation unit 93 that outputs an effect adjustment signal according to the ratio of the number of blocks detected by the high-frequency block density detection unit 92 are provided.
When the input image signal is an encoded compressed image such as MPEG or JPEG, the high frequency block detection unit 91 can detect a high frequency component for each encoded block. For example, a high frequency component can be extracted by detecting an AC coefficient for each coding block.
The high frequency block detection unit 91 determines that the block when a high frequency component equal to or greater than a predetermined value is detected is a high frequency block.

As shown in FIG. 36, for example, a case where the special image 200 is divided into a plurality of blocks and a high frequency component is detected for each block will be described.
Since the block 600 includes an edge of the image pattern, the high frequency block detection unit 91 detects a high frequency component and determines that it is “a high frequency block”. On the other hand, the high-frequency block detection unit 91 cannot detect a high-frequency component and determines that each of the blocks 601 and 602 is “not a high-frequency block” because the blocks 601 and 602 have substantially constant gray values. Thereafter, the same determination is performed for all the divided blocks.
The high-frequency block density detection unit 92 detects the ratio of the number of high-frequency blocks to the total number of blocks divided into a plurality (hereinafter referred to as “block density”).
The effect adjustment signal generation unit 93 outputs the special image effect adjustment signal DS by increasing the value of the special image effect adjustment signal DS as the block density increases in accordance with the block density. For example, as shown in FIG. 37, the value of the special image effect adjustment signal DS is increased in a range where the detected block density is greater than or equal to a predetermined value Thg to a predetermined value Thh. By providing the threshold value in this way, the effect adjustment signal generation unit 93 can generate the special image effect adjustment signal DS that completely eliminates the visual effect when it is equal to or less than the threshold value “Thg” including the special image. On the other hand, the effect adjustment signal generator 93 can generate a special image effect adjustment signal DS for processing without degrading the visual effect when the threshold value “Thh” is greater than or equal to a normal image that is not a special image. Here, the horizontal axis represents the block density, and the vertical axis represents the output of the special image effect adjustment signal DS. Note that the range of the value of the special image effect adjustment signal DS to be output is set from “0.0” to “1.0”, but “0.2” to “1.0” depending on the intensity of visual processing. You may make it adjust to. Further, the visual processing device 1001 is configured so that the effect of the visual processing becomes stronger as the value of the special image effect adjustment signal DS is larger.

As described above, according to the special image detection unit 90 of the third modification, the degree of the special image having the bias of the image information can be detected from the image signal IS, and the special image detection unit 2140 is replaced with the special image detection unit 90. Is possible.
Note that a special image having a statistical information bias is detected from a reduced image such as a thumbnail image in which the image signal is reduced, and an effect adjustment signal is output based on the statistical information bias. Good.
Further, a reduction processing unit (not shown) for reducing the image signal is provided between the image signal and the special image detection unit 2140, 700, 80, or 90, and statistical information is obtained from the reduced image generated by the reduction processing unit. It is also possible to detect a special image having a bias of and output an effect adjustment signal based on the statistical information bias.

By using the reduced image, it is possible to detect a flat region near the edge while suppressing the influence of noise. That is, since the noise component is reduced in the reduced image generated by the reduction method that thins out after averaging the image signals, it is possible to detect a statistical information bias while suppressing the influence of noise. If a reduced image is used, the number of pixels to be detected can be reduced and the amount of calculation can be reduced.
(Embodiment 7)
The visual processing device 1001 according to Embodiment 6 of the present invention outputs a composite signal MUS that is synthesized by changing the ratio of the image signal IS and the peripheral image information (unsharp signal) US according to the effect adjustment signal MOD, The visual processing unit 30 outputs the processing output OS obtained by visually processing the image signal in accordance with the composite signal MUS from the effect adjustment unit 1020. However, in the visual processing device 1002 according to Embodiment 7 of the present invention, the effect adjustment is performed. The unit 2021 outputs a synthesized output OUT obtained by synthesizing the visually processed processing output OS and the image signal IS according to the effect adjustment signal. A visual processing device 1002 according to Embodiment 7 of the present invention will be described with reference to FIG.

FIG. 38 is a block diagram showing the configuration of the visual processing device 1002 according to Embodiment 7 of the present invention. Hereinafter, parts similar to those in the sixth embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
In FIG. 38, the visual processing unit 30 outputs a processing output OS based on the image signal IS and the output US of the spatial processing unit 10.
The effect adjustment unit 2021 performs the internal calculation on the image signal IS and the processing output OS according to the effect adjustment signal MOD, thereby making the visual processing effect different. For example, the output OUT from the effect adjustment unit 2021 is calculated by internal division calculation as shown in the following (Equation 9).
OUT = OS × MOD + IS × (1.0−MOD) (Formula 9)
(Equation 9) can also be realized by modifying it as (Equation 10).

OUT = (OS−IS) × MOD + IS (Formula 10)
As described above, according to the visual processing device 1002 of the seventh embodiment of the present invention, the synthesized signal OUT that is synthesized by changing the ratio of the processed signal OS and the image signal IS according to the effect adjustment signal MOD is output. And the effect of visual processing can be made different.
Note that the special image detection unit 2140 may be replaced with the special image detection unit 700 according to the sixth embodiment of the present invention. In this way as well, a special image can be detected in the same manner, and an effect adjustment signal MOD corresponding to the bias of the image information can be generated.
The special image detection unit 2140 may be replaced with the special image detection unit 80 according to the sixth embodiment of the present invention. In this way as well, a special image can be detected in the same manner, and an effect adjustment signal MOD corresponding to the bias of the image information can be generated.

Further, the special image detection unit 2140 may be replaced with the special image detection unit 90 according to the sixth embodiment of the present invention. In this way as well, a special image can be detected in the same manner, and an effect adjustment signal MOD corresponding to the bias of the image information can be generated.
(Embodiment 8)
The visual processing device 1001 according to Embodiment 6 of the present invention outputs a composite signal MUS that is synthesized by changing the ratio of the image signal IS and the peripheral image information (unsharp signal) US according to the effect adjustment signal MOD, The visual processing unit 30 outputs the processing output OS obtained by visually processing the image signal in accordance with the composite signal MUS from the effect adjustment unit 1020. However, in the visual processing device 1003 according to Embodiment 8 of the present invention, the effect adjustment is performed. The unit 2022 creates a profile (hereinafter referred to as a “composite profile”) that is synthesized by changing the ratio of outputs from a plurality of profiles having different visual processing effects according to the effect adjustment signal MOD. An embodiment in which the LUT is set will be described with reference to FIG.

FIG. 39 is a block diagram showing the configuration of the visual processing device 1003 according to Embodiment 8 of the present invention. Hereinafter, parts similar to those in the sixth embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
The effect adjustment unit 2022 synthesizes the third profile 6000 and the fourth profile 6001 having different visual processing intensities through internal calculation according to the effect adjustment signal MOD, creates a synthesis profile, and creates the synthesized profile in the LUT of the visual processing unit 30. Set. Note that a composite profile may be generated by external division calculation.
The visual processing unit 30 can perform visual processing with different levels of visual processing and different visual effects according to the composite profile set in the LUT.
As described above, according to the visual processing device 1003 of the eighth embodiment of the present invention, a plurality of profiles having different visual processing intensities and effects are synthesized in accordance with the effect adjustment signal MOD, and the synthesized profile is obtained by the visual processing unit 30. The effect of visual processing can be made different by setting to the LUT.

Note that the special image detection unit 2140 may be replaced with the special image detection unit 700 according to the sixth embodiment of the present invention. In this way as well, a special image can be detected in the same manner, and an effect adjustment signal MOD corresponding to the information bias can be generated.
Further, the special image detection unit 2140 may be replaced with the special image detection unit 80 according to the sixth embodiment of the present invention. In this way as well, a special image can be detected in the same manner, and an effect adjustment signal MOD corresponding to the information bias can be generated.
Further, the special image detection unit 2140 may be replaced with the special image detection unit 90 in the sixth embodiment of the present invention. In this way as well, a special image can be detected in the same manner, and an effect adjustment signal MOD corresponding to the information bias can be generated.
(Embodiment 9)
In the visual processing devices according to the sixth embodiment to the eighth embodiment of the present invention, the gradation conversion value based on the two-dimensional gradation conversion characteristics is output. Now, a gain-type visual processing system 1004 that performs gradation conversion using a gain output will be described with reference to FIGS. 40 and 41. FIG.

FIG. 40 is a block diagram showing a configuration of a gain-type visual processing system 1004 according to Embodiment 9 of the present invention, and FIG. 41 is an explanatory diagram for explaining a two-dimensional gain characteristic. Hereinafter, parts similar to those in the sixth embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
40, the gain-type visual processing system 1004 includes a gain-type visual processing device 4005 that outputs a gain signal GAIN obtained by visually processing the image signal IS, and a multiplier 4011 that multiplies the gain signal GAIN and the image signal IS. ing.
The gain-type visual processing device 4005 includes a visual processing device 1001 that outputs a processed signal OS obtained by visually processing the image signal IS, and a divider 4012 that divides the processed signal OS by the image signal IS. Here, the visual processing device 1001 outputs a gradation conversion value obtained by visually processing the output of the image signal IS, and the gain-type visual processing device 4005 is obtained by dividing the gradation conversion value by the image signal IS. realizable.

The multiplier 4011 multiplies the gain signal GAIN output from the gain-type visual processing device 4005 and the image signal IS, and outputs a gradation conversion value obtained by visually processing the image signal IS.
Note that the visual processing unit 30 may directly use a profile having a two-dimensional gain characteristic shown in FIG. Here, the vertical axis of FIG. 41 is the gain output GN, and the horizontal axis is the image signal IS. The two-dimensional gain characteristic shown in FIG. 41 is equivalent to that obtained by dividing the output of the two-dimensional gradation characteristic profile shown in FIG. 22 by the image signal IS. A profile having this two-dimensional gain characteristic may be set in the LUT of the visual processing unit 30 of the visual processing device 1001. As described above, if the profile of the two-dimensional gain characteristic is set in advance in the LUT of the visual processing unit 30, the gain output GN and the gain signal GAIN are equivalent. Therefore, even if the divider 12 is deleted, the gain-type visual processing device 4005 is used. Can be realized.

As described above, in the gain-type visual processing system 1004 according to Embodiment 9 of the present invention, the gain-type visual processing device 4005 has a small change in the processed signal visually processed with respect to the change in the input image signal IS. The number of bits of the input signal can be reduced, and the circuit scale can be reduced. Further, when the visual processing unit 30 is provided with a two-dimensional LUT, the memory capacity can be reduced.
The visual processing device 1001 according to the sixth embodiment of the present invention may be replaced with the visual processing device 1002 according to the seventh embodiment of the present invention. This also makes it possible to realize the gain-type visual processing device 4005.
The visual processing device 1001 according to the sixth embodiment of the present invention may be replaced with the visual processing device 1003 according to the eighth embodiment of the present invention. This also makes it possible to realize the gain-type visual processing device 4005.

As described above, according to Embodiment 6 to Embodiment 9 of the present invention, when a normal image that is not a special image is input, the visual processing effect can be maintained, and the special image is input. In some cases, side effects can be suppressed.
(Embodiment 10)
Various functions such as a spatial processing function, an effect adjustment function, and a visual processing function in the visual processing device or the visual processing system described in the embodiment of the present invention may be implemented by hardware using an integrated circuit or the like. It may be implemented by software that operates using a central processing unit (hereinafter referred to as “CPU”), a digital signal processing unit, or the like. Further, the above various functions may be realized by a mixed process of software and hardware.
First, when the various functions described above are implemented by hardware, each function in the embodiment of the present invention may be individually integrated circuits, or may be integrated as a single chip so as to include some or all of them. Also good. The integrated circuit here is not limited to an LSI, and may be referred to as an IC, a system LSI, a super LSI, or an ultra LSI depending on the degree of integration.

The integrated circuit may be realized by a dedicated circuit or a general-purpose processor. For example, an FPGA (Field Programmable Gate Array) that can be programmed after manufacturing a semiconductor chip, or a reconfigurable processor that can reconfigure the connection and setting of cells inside the integrated circuit may be used.
Further, if integrated circuit technology comes out as a result of advances in semiconductor technology or other derived technology, it is naturally also possible to carry out function block integration using this technology. For example, biocomputers may be applied due to advances in biotechnology.
Next, a case where the above various functions are implemented by software will be described with reference to FIG.
FIG. 46 is a block diagram showing a configuration of a computer according to the embodiment of the present invention.

In FIG. 46, a computer 4612 includes a CPU 4600 that executes instructions of various programs, a read-only memory 4601 (hereinafter referred to as “ROM 4601”) in which programs are stored, and a random access memory 4602 that stores data in temporary storage. (Hereinafter referred to as “RAM 4602”), an input unit 4603 for inputting an image, an output unit 4604 for outputting an image, and a storage unit 4605 for storing programs and various data.
Furthermore, a communication unit 4606 for performing communication with the outside and a drive 4607 for appropriately connecting an information storage medium may be provided.
Each functional unit transmits and receives control signals and data via the bus 4610.
The CPU 4600 executes various functions according to programs stored in the ROM 4601.

The ROM 4601 stores programs, profiles, and the like.
The RAM 4602 temporarily stores data necessary for processing of various functions by the CPU 100.
An image is input to the input unit 4603. For example, a video signal is acquired by receiving a radio wave and decoding the received signal. Further, a digital image may be acquired directly via a wire.
The output unit 4604 outputs an image. For example, the data is output to a display device such as a liquid crystal display device or a plasma display.
The storage unit 4605 is composed of a magnetic memory or the like, and stores various programs and data.

The communication unit 4606 may be connected to the network 111 and acquire the program via the network 111 or install the acquired program in the storage unit 4605 as necessary. As a result, the computer 6 can download the program through the communication unit 4606.
The drive 4607 appropriately connects an information storage medium, and acquires storage information stored in the information storage medium. The information storage medium is, for example, a disk 4608 such as a magnetic disk, a magneto-optical disk, or an optical disk, or a memory card 4609 such as a semiconductor memory.
Note that a program, a profile, and the like for executing various functions may be stored in the disk 4608 or a memory card 4609 such as a semiconductor memory, and the information may be given to the computer 4612.

Further, the program may be incorporated in advance with dedicated hardware in the computer, or may be provided by being incorporated in the ROM 4601 and the storage unit 4605 in advance.
The program can be applied to devices that handle images, such as information processing apparatuses, televisions, digital cameras, mobile phones, and PDAs. The program is incorporated in or connected to a device that handles images, and executes visual processing similar to the visual processing realized by the visual processing device or the visual processing system described in the above embodiment.
When the visual processing device is applied to a display device or the like, the display mode may be switched when a special image is detected.
Further, when the visual processing unit or the like of the visual processing device described in the above embodiment is configured with a two-dimensional LUT, the data for the two-dimensional LUT that is referred to is stored in a storage device such as a hard disk or a ROM and is necessary. Referenced according to. Furthermore, the data of the two-dimensional LUT is provided from a two-dimensional gain data (profile) providing device for the two-dimensional LUT that is directly connected to the visual processing device or indirectly connected via the network. It may be a thing.

When the first visual processing method is realized, for example, an effect adjustment step for performing processing for setting the effect of visual processing on the computer 4612 according to the effect adjustment signal, and visual processing on the input image signal are performed. A visual processing step for performing a predetermined level, a target level setting step for setting a predetermined target level, and a spatial processing step for performing a predetermined spatial processing on the image signal and outputting a processed signal. Then, in the effect adjustment step, the computer 4612 outputs a synthesized signal obtained by synthesizing a predetermined target level and the processing signal according to the effect adjustment signal, and in the visual processing step, based on the synthesized signal and the image signal synthesized. To convert the gradation of the image signal.
When the second visual processing method is realized, for example, an effect adjustment step for performing processing for setting the effect of visual processing on the computer 4612 according to the effect adjustment signal, and visual processing on the input image signal are performed. Performing a visual processing step, a peripheral image information extracting step for extracting peripheral image information of the input image signal, and an effect adjustment signal generating step for outputting an effect adjustment signal for setting the effect of the visual processing. Let Then, in the visual processing step, the computer 4612 is caused to visually process the image signal based on the image signal and the peripheral image information, and in the effect adjustment step, the effect of the visual processing is set according to the effect adjustment signal.

Further, when realizing the third visual processing method, for example, the computer 4612 realizes the second visual processing method, and in the effect adjustment signal generation step, a flat region adjacent to the edge region is detected from the image signal. Detect and output an effect adjustment signal.
When the fourth visual processing method is realized, for example, the computer 4612 performs an effect adjustment step for performing processing for setting the effect of visual processing according to the effect adjustment signal, and the input image signal is subjected to visual processing. A visual processing step for performing a peripheral image information extraction step for extracting peripheral image information of the input image signal, detecting a special image having a statistical information bias from the image signal, and detecting a statistical information bias And a special image detecting step for outputting an effect adjustment signal based on the degree. Then, in the visual processing step, the computer 4612 is caused to visually process the image signal based on the image signal and the peripheral image information, and in the effect adjustment step, the effect of the visual processing is set according to the effect adjustment signal.

(Embodiment 11)
Next, as an eleventh embodiment, an application example of the visual processing device described in the above embodiment and a system using the same will be described with reference to FIGS.
FIG. 42 is a block diagram showing an overall configuration of a content supply system ex100 that implements a content distribution service. The communication service providing area is divided into desired sizes, and base stations ex107 to ex110, which are fixed wireless stations, are installed in each cell.
This content supply system ex100 includes, for example, a computer ex111, a PDA (Personal Digital Assistant) ex112, a camera ex113, a mobile phone ex114, a camera via the Internet ex101, the Internet service provider ex102, the telephone network ex104, and the base stations ex107 to ex110. Each device such as the attached mobile phone ex115 is connected.

However, the content supply system ex100 is not limited to the combination shown in FIG. 42, and any combination may be connected. Also, each device may be directly connected to the telephone network ex104 without going through the base stations ex107 to ex110 which are fixed wireless stations.
The camera ex113 is a device capable of shooting a moving image such as a digital video camera. In addition, the mobile phone may be a PDC (Personal Digital Communications) system, a CDMA (Code Division Multiple Access) system, a W-CDMA (Wideband-Code Division Multiple Access) system, or a GSM (Global Mobile System). Alternatively, PHS (Personal Handyphone System) may be used.

  Further, the streaming server ex103 is connected from the camera ex113 through the base station ex109 and the telephone network ex104, and live distribution based on the encoded data transmitted by the user using the camera ex113 becomes possible. The encoded processing of the captured data may be performed by the camera ex113 or may be performed by a server or the like that performs data transmission processing. The moving image data shot by the camera ex116 may be transmitted to the streaming server ex103 via the computer ex111. The camera ex116 is a device such as a digital camera that can shoot still images and moving images. In this case, the moving image data may be encoded by the camera ex116 or the computer ex111. The encoding process is performed in the LSI ex117 included in the computer ex111 and the camera ex116. Note that image encoding / decoding software may be incorporated into any storage medium (CD-ROM, flexible disk, hard disk, or the like) that is a recording medium readable by the computer ex111 or the like. Furthermore, you may transmit moving image data with the mobile phone ex115 with a camera. The moving image data at this time is data encoded by the LSI included in the mobile phone ex115.

  In the content supply system ex100, the content (for example, video shot of music live) captured by the user with the camera ex113, the camera ex116, and the like is encoded and transmitted to the streaming server ex103, while the streaming server ex103. Distributes the content data to the requested client. Examples of the client include a computer ex111, a PDA ex112, a camera ex113, and a mobile phone ex114 that can decode the encoded data. In this way, the content supply system ex100 can receive and play back the encoded data at the client, and can also receive a private broadcast by receiving, decoding, and playing back at the client in real time. It is a system that becomes possible.

When displaying content, the visual processing device described in the embodiment may be used. For example, the computer ex111, the PDA ex112, the camera ex113, the mobile phone ex114, and the like may be provided with the visual processing device described in the above-described embodiment, and realize a visual processing method and a visual processing program.
The streaming server ex103 may provide the two-dimensional gain data (profile) to the visual processing device via the Internet ex101. Furthermore, there may be a plurality of streaming servers ex103 that provide different two-dimensional gain data. Furthermore, the streaming server ex103 may create two-dimensional gain data. As described above, when the visual processing device can acquire the two-dimensional gain data via the Internet ex101, the visual processing device does not need to store the two-dimensional gain data used for the visual processing in advance, and stores the visual processing device. It is also possible to reduce the capacity. Further, since two-dimensional gain data can be acquired from a plurality of servers connected via the Internet ex101, different visual processing can be realized.

A mobile phone will be described as an example.
FIG. 43 is a diagram illustrating a mobile phone ex115 including the visual processing device 1 according to the embodiment. The mobile phone ex115 includes an antenna ex201 for transmitting and receiving radio waves to and from the base station ex110, a video from a CCD camera, a camera unit ex203 capable of taking a still image, a video shot by the camera unit ex203, and an antenna ex201. A display unit ex202 such as a liquid crystal display for displaying data obtained by decoding received video and the like, a main body unit composed of a group of operation keys ex204, an audio output unit ex208 such as a speaker for audio output, and audio input To store encoded data or decoded data such as a voice input unit ex205 such as a microphone, captured video or still image data, received mail data, video data or still image data, etc. Recording media ex207, mobile phone ex115 recording media ex And a slot portion ex206 that enables mounting 07. The recording medium ex207 stores a flash memory element, which is a kind of EEPROM (Electrically Erasable and Programmable Read Only Memory), which is a nonvolatile memory that can be electrically rewritten and erased, in a plastic case such as an SD card.

Further, the cellular phone ex115 will be described with reference to FIG. The mobile phone ex115 controls the main control unit ex311 which controls the respective units of the main body unit including the display unit ex202 and the operation key ex204. The power supply circuit unit ex310, the operation input control unit ex304, and the image encoding Unit ex312, camera interface unit ex303, LCD (Liquid Crystal Display) control unit ex302, image decoding unit ex309, demultiplexing unit ex308, recording / playback unit ex307, modulation / demodulation circuit unit ex306, and audio processing unit ex305 via a synchronization bus ex313 Are connected to each other.
When the end of call and the power key are turned on by a user operation, the power supply circuit ex310 activates the camera-equipped digital mobile phone ex115 by supplying power from the battery pack to each unit. .

The mobile phone ex115 converts the voice signal collected by the voice input unit ex205 in the voice call mode into digital voice data by the voice processing unit ex305 based on the control of the main control unit ex311 including a CPU, ROM, RAM, and the like. The modulation / demodulation circuit unit ex306 performs spread spectrum processing, the transmission / reception circuit unit ex301 performs digital analog conversion processing and frequency conversion processing, and then transmits the result via the antenna ex201. In addition, the cellular phone ex115 amplifies the received signal received by the antenna ex201 in the voice call mode, performs frequency conversion processing and analog-digital conversion processing, performs spectrum despreading processing by the modulation / demodulation circuit unit ex306, and analog audio by the voice processing unit ex305. After conversion into a signal, this is output via the audio output unit ex208.
Further, when an e-mail is transmitted in the data communication mode, text data of the e-mail input by operating the operation key ex204 of the main body is sent to the main control unit ex311 via the operation input control unit ex304. The main control unit ex311 performs spread spectrum processing on the text data in the modulation / demodulation circuit unit ex306, performs digital analog conversion processing and frequency conversion processing in the transmission / reception circuit unit ex301, and then transmits the text data to the base station ex110 via the antenna ex201.

When transmitting image data in the data communication mode, the image data captured by the camera unit ex203 is supplied to the image encoding unit ex312 via the camera interface unit ex303. When image data is not transmitted, the image data captured by the camera unit ex203 can be directly displayed on the display unit ex202 via the camera interface unit ex303 and the LCD control unit ex302.
The image encoding unit ex312 converts the image data supplied from the camera unit ex203 into encoded image data by compression encoding, and sends the encoded image data to the demultiplexing unit ex308. At the same time, the cellular phone ex115 sends the sound collected by the audio input unit ex205 during imaging by the camera unit ex203 to the demultiplexing unit ex308 as digital audio data via the audio processing unit ex305.

The demultiplexing unit ex308 multiplexes the encoded image data supplied from the image encoding unit ex312 and the audio data supplied from the audio processing unit ex305 by a predetermined method, and the resulting multiplexed data is a modulation / demodulation circuit unit Spread spectrum processing is performed in ex306, digital analog conversion processing and frequency conversion processing are performed in the transmission / reception circuit unit ex301, and then transmitted through the antenna ex201.
When data of a moving image file linked to a home page or the like is received in the data communication mode, the received signal received from the base station ex110 via the antenna ex201 is subjected to spectrum despreading processing by the modulation / demodulation circuit unit ex306, and the resulting multiplexing is obtained. Data is sent to the demultiplexing unit ex308.
In addition, in order to decode the multiplexed data received via the antenna ex201, the demultiplexing unit ex308 separates the multiplexed data to generate an encoded bitstream of image data and an encoded bitstream of audio data. The encoded image data is supplied to the image decoding unit ex309 via the synchronization bus ex313, and the audio data is supplied to the audio processing unit ex305.

Next, the image decoding unit ex309 generates reproduction moving image data by decoding the encoded bit stream of the image data, and supplies this to the display unit ex202 via the LCD control unit ex302, thereby For example, moving image data included in a moving image file linked to a home page is displayed. At the same time, the audio processing unit ex305 converts the audio data into an analog audio signal and then supplies the analog audio signal to the audio output unit ex208. Thus, for example, the audio data included in the moving image file linked to the home page is reproduced. The
In the above configuration, the image decoding unit ex309 may include the visual processing device of the above embodiment.
In addition, the present invention is not limited to the above system, and recently, digital broadcasting by satellite and terrestrial has become a hot topic. As shown in FIG. 45, the visual processing device described in the above embodiment is also incorporated in the digital broadcasting system. Can do. Specifically, in the broadcasting station ex409, a coded bit stream of video information is transmitted to a communication or broadcasting satellite ex410 via radio waves. Receiving this, the broadcasting satellite ex410 transmits a radio wave for broadcasting, and receives the radio wave with a home antenna ex406 having a satellite broadcasting receiving facility, such as a television (receiver) ex401 or a set top box (STB) ex407. The device decodes the encoded bit stream and reproduces it. Here, a device such as the television (receiver) ex401 or STBex407 may include the visual processing device described in the above embodiment. Moreover, you may use the visual processing method of the said embodiment. Furthermore, a visual processing program may be provided. In addition, the visual processing device, the visual processing method, and the visual processing program described in the above embodiment are also applied to the playback device ex403 that reads and decodes the encoded bitstream recorded on the storage medium ex402 such as a CD or DVD as a recording medium. It is possible to implement. In this case, the reproduced video signal is displayed on the monitor ex404. In addition, the visual processing device, the visual processing method, and the visual processing program described in the above embodiment are installed in the STBex 407 connected to the cable ex405 for cable television or the antenna ex406 for satellite / terrestrial broadcasting. A configuration of reproducing with ex408 is also conceivable. At this time, the visual processing device described in the above embodiment may be incorporated in the television instead of the STB. It is also possible to receive a signal from the satellite ex410 or the base station ex107 by the car ex412 having the antenna ex411 and reproduce a moving image on a display device such as the car navigation ex413 that the car ex412 has.

Furthermore, an image signal can be encoded and recorded on a recording medium. Specific examples include a recorder ex420 such as a DVD recorder that records image signals on a DVD disk ex421 and a disk recorder that records data on a hard disk. Further, it can be recorded on the SD card ex422. If the recorder ex420 includes the visual processing device of the above embodiment, the image signal recorded on the DVD disc ex421 or the SD card ex422 can be interpolated and reproduced and displayed on the monitor ex408.
For example, the configuration of the car navigation ex413 may be a configuration excluding the camera unit ex203, the camera interface unit ex303, and the image encoding unit ex312 in the configuration illustrated in FIG. Machine) Ex401 can also be considered.

In addition to the transmission / reception type device having both the encoder and the decoder, the mobile phone ex114 and the like are mounted in three mounting formats: a transmitter only with an encoder and a receiver only with a decoder. Can be considered.
The specific configuration of the present invention is not limited to the above-described embodiment, and various changes and modifications can be made without departing from the scope of the invention.
[Appendix]
The present invention can also be expressed as follows.
(Appendix 1)
In a visual processing device that visually processes and outputs an input image signal,
An effect adjustment unit that performs processing for setting the effect of visual processing according to the effect adjustment signal;
A visual processing unit for performing visual processing on the image signal;
A visual processing device comprising:
(Appendix 2)
A target level setting unit for setting a predetermined target level;
A spatial processing unit that performs predetermined spatial processing on the image signal and outputs a processing signal;
Further comprising
The effect adjustment unit outputs a composite signal obtained by combining the predetermined target level and the processing signal in accordance with the effect adjustment signal for setting the effect of visual processing.
The visual processing unit performs gradation conversion on the image signal based on the synthesized signal and the image signal.
The visual processing device according to attachment 1.
(Appendix 3)
A target level setting unit for setting a predetermined target level;
A spatial processing unit that performs predetermined spatial processing on the image signal and outputs a processing signal;
A correction unit for correcting the image signal;
Further comprising
The effect adjustment unit outputs a composite signal obtained by combining the predetermined target level and the processing signal in accordance with the effect adjustment signal for setting the effect of visual processing.
The visual processing unit outputs a gain signal based on the composite signal and the image signal,
The correction unit corrects the image signal based on the gain signal.
The visual processing device according to attachment 1.
(Appendix 4)
A spatial processing unit that performs predetermined spatial processing on the image signal and outputs a processing signal;
The effect adjustment unit outputs a composite signal obtained by combining the image signal and the processing signal in accordance with the effect adjustment signal for setting the effect of visual processing.
The visual processing unit performs gradation conversion on the image signal based on the synthesized signal and the image signal.
The visual processing device according to attachment 1.
(Appendix 5)
A spatial processing unit that performs predetermined spatial processing on the image signal and outputs a processing signal;
A correction unit for correcting the image signal;
Further comprising
The effect adjustment unit outputs a composite signal obtained by combining the image signal and the processing signal in accordance with the effect adjustment signal for setting the effect of visual processing.
The visual processing unit outputs a gain signal based on the synthesized signal and the image signal synthesized,
The correction unit corrects the image signal based on the gain signal.
The visual processing device according to attachment 1.
(Appendix 6)
The visual processing unit includes a two-dimensional lookup table;
The visual processing device according to any one of appendix 1 to appendix 5.
(Appendix 7)
A peripheral image information extraction unit that extracts peripheral image information of the input image signal;
An effect adjustment signal generator for outputting the effect adjustment signal for setting the effect of the visual processing;
Further comprising
The visual processing unit visually processes the image signal based on the image signal and the peripheral image information,
The effect adjustment unit sets the effect of the visual processing according to the effect adjustment signal.
The visual processing device according to attachment 1.
(Appendix 8)
The effect adjustment signal generator detects an area adjacent to an edge area from the image signal and outputs the effect adjustment signal;
The visual processing device according to appendix 7.
(Appendix 9)
The effect adjustment signal generation unit detects a flat region adjacent to an edge region from the image signal and outputs the effect adjustment signal.
The visual processing device according to attachment 8.
(Appendix 10)
The effect adjustment signal generation unit outputs the effect adjustment signal according to a change amount of the peripheral image information.
The visual processing device according to appendix 8 or appendix 9.
(Appendix 11)
The effect adjustment signal generator is
A flatness detecting unit for detecting a flatness degree of a flat area where a luminance difference with an adjacent area is a predetermined value or less from the image signal;
An edge detection unit that detects an edge amount of an edge region in which a luminance difference with an adjacent region is a predetermined value or more from the image signal;
Have
The effect adjustment signal generation unit outputs the effect adjustment signal based on outputs from the flatness detection unit and the edge detection unit,
The visual processing device according to appendix 8 or appendix 9.
(Appendix 12)
The effect adjustment unit outputs a first synthesized signal obtained by synthesizing the image signal and the peripheral image information according to the effect adjustment signal,
The visual processing unit visually processes the image signal based on the first synthesized signal and the image signal;
The visual processing device according to any one of appendix 7 to appendix 11.
(Appendix 13)
The effect adjustment unit outputs a second synthesized signal obtained by synthesizing the image signal and the output visually processed by the visual processing unit according to the effect adjustment signal.
The visual processing device according to any one of appendix 7 to appendix 11.
(Appendix 14)
A peripheral image information extraction unit that extracts peripheral image information of the input image signal;
A special image detecting unit that detects a degree of a special image having a statistical information bias from the image signal based on the statistical information bias, and outputs the detected degree as the effect adjustment signal;
Further comprising
The visual processing unit outputs a processed signal obtained by visually processing the image signal based on the image signal and the peripheral image information;
The effect adjustment unit controls the visual processing unit to set the effect of the visual processing according to the effect adjustment signal.
The visual processing device according to attachment 1.
(Appendix 15)
The special image detecting unit detects the bias of the statistical information based on a ratio of a region where the shading changes or a ratio of a region where the shading does not change in the image of the image signal;
The visual processing device according to attachment 14.
(Appendix 16)
The special image detection unit increases the degree of the special image when the ratio of the area where the shading changes is small or when the ratio of the area where the shading does not change is large.
The visual processing device according to attachment 15.
(Appendix 17)
The special image detection unit detects a ratio of a region where the shading changes by detecting an edge component in the image;
The visual processing device according to attachment 16.
(Appendix 18)
The special image detection unit detects a ratio of a region where the shading does not change by detecting a degree of flatness in the image;
The visual processing device according to attachment 16.
(Appendix 19)
The special image detection unit detects the flatness based on the number of gradation levels or the continuous length of similar pixels.
The visual processing device according to appendix 18.
(Appendix 20)
The special image detection unit
An edge detection unit for detecting an edge amount for each pixel from the image signal;
An edge density calculator that detects edge pixels having an edge amount equal to or greater than a predetermined value, and calculates a ratio of the number of edge pixels to the total number of pixels of the image signal;
A first effect adjustment signal generator that outputs the effect adjustment signal according to the ratio;
Having
The visual processing device according to appendix 17.
(Appendix 21)
The special image detection unit
A high-frequency block detector that detects a high-frequency block including a high-frequency component from the image signal divided into a plurality of blocks;
A high-frequency block density detector that detects a ratio of the number of high-frequency blocks to the plurality of blocks;
A second effect adjustment signal generator for outputting the effect adjustment signal according to the ratio;
Having
The visual processing device according to appendix 17.
(Appendix 22)
The special image detection unit
A frequency detector for detecting the frequency of each gradation level from the image signal;
A frequency determination unit that compares the frequency for each gradation level with a predetermined threshold and detects a gradation level with the frequency greater than the predetermined threshold;
A gradation number detection unit for detecting the number of gradation levels determined by the frequency determination unit as having a high frequency;
A third effect adjustment signal generator for outputting the effect adjustment signal according to the number of gradation levels;
Having
The visual processing device according to appendix 19.
(Appendix 23)
The special image detection unit
A similar luminance detection unit for detecting a similar pixel in which a luminance difference with an adjacent pixel is equal to or less than a predetermined value from the image signal;
A continuous length detection unit for detecting a continuous length in which the similar pixels are continuous;
An average continuous length calculation unit that calculates an average continuous length by averaging the plurality of continuous lengths detected by the continuous length detection unit;
A fourth effect adjustment signal generator for outputting the effect adjustment signal according to the average continuous length;
Having
The visual processing device according to appendix 19.
(Appendix 24)
The effect adjustment unit outputs a first synthesized signal synthesized by changing a ratio of the image signal and the peripheral image information according to the effect adjustment signal,
The visual processing unit performs the visual processing on the image signal based on the first synthesized signal and the image signal;
Item 24. The visual processing device according to any one of items 14 to 23.
(Appendix 25)
The effect adjustment unit outputs a second synthesized signal synthesized by changing a ratio between the image signal and the processing signal according to the effect adjustment signal.
Item 24. The visual processing device according to any one of items 14 to 23.
(Appendix 26)
The visual processing unit has a two-dimensional lookup table, performs the visual processing based on characteristic data set in the two-dimensional lookup table,
The effect adjustment unit sets characteristic data synthesized by changing a ratio of a plurality of the characteristic data having different effects of the visual processing according to the effect adjustment signal in the visual processing unit.
Item 24. The visual processing device according to any one of items 14 to 23.
(Appendix 27)
The special image detection unit inputs a reduced image in which the image signal is reduced, detects the special image having the statistical information bias from the reduced image, and based on the statistical information bias. To output the effect adjustment signal,
Item 27. The visual processing device according to any one of items 14 to 26.
(Appendix 28)
The special image detection unit detects bias of the statistical information from one or more previous frame images when the image signal is a frame image, or from one or more previous field images when the image signal is a field image;
Item 28. The visual processing device according to any one of items 14 to 27.
(Appendix 29)
A continuous change processing unit for continuously changing the effect adjustment signal;
The continuous change processing unit continuously outputs the effect adjustment signal between the frames when the effect adjustment signal is output in units of frames, and between the fields when the effect adjustment signal is output in units of fields. To change,
The visual processing device according to attachment 28.
(Appendix 30)
A data receiving unit for receiving image data transmitted or broadcast;
A decoding unit for decoding the received image data into video data;
30. The visual processing device according to any one of appendix 1 to appendix 29, wherein the decoded video data is visually processed to output an output signal;
A display unit for displaying the output signal visually processed by the visual processing device;
A display device comprising:
(Appendix 31)
In a visual processing method for visually processing and outputting an input image signal,
An effect adjustment step for performing processing for setting the effect of visual processing according to the effect adjustment signal;
Visual processing step for performing visual processing on the image signal;
A visual processing method comprising:
(Appendix 32)
A target level setting step for setting a predetermined target level;
A spatial processing step of performing predetermined spatial processing on the image signal and outputting a processed signal;
The effect adjustment step outputs a synthesized signal obtained by synthesizing the predetermined target level and the processing signal in accordance with an effect adjustment signal.
The visual processing step performs gradation conversion on the image signal based on the synthesized signal and the image signal synthesized.
The visual processing method according to attachment 31.
(Appendix 33)
A peripheral image information extraction step for extracting peripheral image information of the input image signal;
An effect adjustment signal generating step for outputting the effect adjustment signal for setting the effect of the visual processing;
Further comprising
The visual processing step visually processing the image signal based on the image signal and the peripheral image information;
The effect adjustment step sets the effect of the visual processing according to the effect adjustment signal.
The visual processing method according to attachment 31.
(Appendix 34)
The effect adjustment signal generation step detects a flat region adjacent to an edge region from the image signal and outputs the effect adjustment signal.
The visual processing method according to attachment 33.
(Appendix 35)
A peripheral image information extraction step for extracting peripheral image information of the input image signal;
A special image detecting step of detecting a special image having a statistical information bias from the image signal and outputting the effect adjustment signal based on a degree of the statistical information bias;
Further comprising
The visual processing step visually processing the image signal based on the image signal and the peripheral image information;
The effect adjustment step sets the effect of the visual processing according to the effect adjustment signal.
The visual processing method according to attachment 31.
(Appendix 36)
In order to perform visual processing to output and output the input image signal,
An effect adjustment step for outputting a control signal for setting the effect of visual processing according to the effect adjustment signal;
A visual processing step of visually processing the image signal based on the control signal and the image signal;
A program that executes
(Appendix 37)
On the computer,
A target level setting step for setting a predetermined target level;
A spatial processing step of performing predetermined spatial processing on the image signal and outputting a processed signal;
Is a program for further executing
The effect adjustment step outputs a synthesized signal obtained by synthesizing the predetermined target level and the processing signal according to the effect adjustment signal for setting the effect of visual processing.
The visual processing step performs gradation conversion on the image signal based on the synthesized signal and the image signal synthesized.
The program according to attachment 36.
(Appendix 38)
On the computer,
A peripheral image information extraction step for extracting peripheral image information of the input image signal;
An effect adjustment signal generating step for outputting the effect adjustment signal for setting the effect of the visual processing;
Is a program for further executing
The visual processing step visually processing the image signal based on the image signal and the peripheral image information;
The effect adjustment step adjusts to make the effect of the visual processing different according to the effect adjustment signal.
The program according to attachment 36.
(Appendix 39)
The effect adjustment signal generation step detects a flat region adjacent to an edge region from the image signal and outputs the effect adjustment signal.
The program according to attachment 38.
(Appendix 40)
On the computer,
A peripheral image information extraction step for extracting peripheral image information of the input image signal;
A special image detecting step for detecting a special image having a statistical information bias from the image signal, and outputting an effect adjustment signal based on a degree of the statistical information bias;
Is a program for further executing
The visual processing step visually processing the image signal based on the image signal and the peripheral image information;
The effect adjustment step sets the effect of the visual processing according to the effect adjustment signal.
The program according to attachment 38.
(Appendix 41)
30. An integrated circuit including the visual processing device according to any one of appendix 1 to appendix 29.

  According to the visual processing device, the display device, the visual processing method, the program, and the integrated circuit according to the present invention, side effects can be suppressed even when an image having a steep edge region or a special image is input. In addition, since the intensity of visual processing of images can be changed in real time with a simple configuration, color television receivers, portable devices, information processing devices, digital still cameras, display devices such as game machines, projectors It can be used for an output device such as a printer.

The block diagram of the visual processing apparatus in Embodiment 1 of this invention. Characteristic diagram of target level setting unit in the same embodiment Explanatory drawing of unsharp signal US and output signal OS in the same embodiment Explanatory drawing about the local contrast characteristic in the same embodiment Explanatory drawing of DR compression characteristic in the same embodiment Block diagram of Modification 1 of the visual processing device according to the embodiment Illustration of gradation characteristics in the same embodiment Explanatory diagram of gain characteristics in the same embodiment The block diagram which shows the structure of the visual processing apparatus of Embodiment 1 of this invention. Explanatory drawing for explaining the two-dimensional gradation characteristics Explanatory drawing for demonstrating the output of the processing signal OS Block diagram showing the configuration of the control signal generator Explanatory drawing for demonstrating the output of the same effect adjustment signal Flow chart for explaining the operation of the visual processing device The block diagram which shows the structure of the control signal generation part of the modification Explanatory drawing for demonstrating the effect adjustment signal of the modification The block diagram which shows the structure of the visual processing apparatus in Embodiment 2 of this invention. The block diagram which shows the structure of the visual processing apparatus in Embodiment 3 of this invention. The block diagram which shows the structure of the visual processing system in Embodiment 4 of this invention. Explanatory diagram for explaining the two-dimensional gain characteristics The block diagram which shows the structure of the visual processing apparatus of Embodiment 6 of this invention. Explanatory drawing for explaining the two-dimensional gradation characteristics Explanatory diagram for explaining the output of the processed signal Block diagram showing the configuration of the special image detection unit Explanatory drawing for explaining the special image Explanatory drawing for explaining the edge pixel Explanatory drawing for demonstrating the output of the same effect adjustment signal Flowchart for explaining the operation of the visual processing device and configuration diagram of the continuous change processing unit The block diagram which shows the structure of the special image detection part of the modification 1 Explanatory drawing for demonstrating the frequency distribution detected by the frequency detection part of the modification 1 Explanatory drawing for demonstrating the effect adjustment signal of the modification 1 The block diagram which shows the structure of the special image detection part of the modification 2 Explanatory drawing for demonstrating the continuous length of the modification 2 Explanatory drawing for demonstrating the effect adjustment signal of the modification 2 The block diagram which shows the structure of the special image detection part of the modification 3 Explanatory drawing for demonstrating the block image of the modification 3 Explanatory drawing for demonstrating the effect adjustment signal of the modification 3 The block diagram which shows the structure of the visual processing apparatus in Embodiment 7 of this invention. The block diagram which shows the structure of the visual processing apparatus in Embodiment 8 of this invention. The block diagram which shows the structure of the visual processing system in Embodiment 9 of this invention. Explanatory diagram for explaining the two-dimensional gain characteristics Overall configuration diagram of a content supply system in Embodiment 2 of the present invention Front view of a mobile phone equipped with the visual processing device according to the embodiment A block diagram for explaining the overall configuration of the mobile phone according to the embodiment Explanatory drawing about the whole structure of the system for digital broadcasting in the same embodiment A block diagram for explaining an example of a computer system in the embodiment Block diagram of a conventional visual processing device Characteristics of gradation conversion in the same device

Explanation of symbols

1, 20, 101, 102, 103, 104, 1001, 1002, 1003, 1004 Visual processing device 2, 10 Spatial processing unit 3, 21, 30, 31, 32 Visual processing unit 4 Target level setting unit 5, 1020, 1021 1022, 2021, 2022 Effect adjusting unit 22 Multiplying unit 40 Control signal generating unit 41 Edge detecting unit 42 Edge proximity detecting unit 43 Flatness detecting unit 44, 2144, 704, 84, 93 Effect adjusting signal generating unit 2140, 700, 80, 90 Special image detection unit 50 Continuous change processing unit 2141 Edge detection unit 2142 Edge amount determination unit 2143 Edge density calculation unit 2144 Effect adjustment signal generation unit 701 Frequency detection unit 702 Frequency determination unit 703 Tone number detection unit 81 Similar luminance detection unit 82 Continuous length detector 83 Average continuous length calculator 91 High frequency block detection 92 frequency block density detection portion 1905,4005 gain type visual processing device

Claims (6)

In a visual processing device that visually processes and outputs an input image signal,
A spatial processing unit that performs predetermined spatial processing on the image signal and outputs a processing signal;
In accordance with an effect adjustment signal for setting the effect of visual processing, an effect adjustment unit that outputs a combined signal obtained by combining the image signal and the processing signal;
A visual processing unit that performs visual processing based on the composite signal and the image signal;
Including a visual processing device.   The visual processing device according to claim 1, wherein the visual processing unit outputs a gain signal based on the synthesized signal and the image signal. Furthermore, a correction unit for correcting the image signal is provided,
The visual processing device according to claim 2, wherein the correction unit corrects the image signal based on the gain signal.   The visual processing device according to claim 1, wherein the visual processing unit is a two-dimensional lookup table and has a two-dimensional gain characteristic. A processor used in an image output device that outputs an image,
The image output device can set an effect adjustment signal for setting the effect of visual processing,
The processor is
A predetermined spatial processing is performed on the image signal, a processed signal is output,
In response to the effect adjustment signal, a combined signal obtained by combining the image signal and the processing signal is output,
Visual processing is performed based on the composite signal and the image signal.
Processor.   An image output device comprising the visual processing device according to claim 1.

Images