JPH11308576A - Image processing method and system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve quality of a display image by reducing a fogged color or the like. SOLUTION: This system is provided with a memory 2, an interlaced signal storage circuit 1 that receives an interlaced signal and stores image data to the memory 2, a pixel comparator circuit 3 that compares pixel data in pluralities of directions of lines tying pixels above and under a pixel of the interpolation line based on the image data stored in the memory 2 and detects a direction in which the compared value is minimized as a tilt of the same color system, an interpolation circuit 4 that interpolates the line based on tilt information from the pixel comparator circuit 3 and a noninterlaced signal output circuit 5 that outputs a noninterlace signal to a display device based on interpolation data of the interpolation circuit 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for storing image data of an input interlaced signal in a memory, converting the interlaced signal into a non-interlaced signal based on the stored image data, and providing the same to a display device. The present invention relates to an image processing method and apparatus having an output function.

[0002]

2. Description of the Related Art FIG. 10 is a diagram for converting an interlaced signal into a non-interlaced signal. Conversion method is even
The data of the odd line is interpolated with respect to the image data of the field, and is converted into image data of one frame. Also o
Similarly, the image data of the dd field is interpolated from the data of the even line and converted into image data of one frame.

FIG. 10 shows an example of conversion of an even field. In FIG. 10, an interpolation line (indicated by a broken-line circle) is inserted between even lines (indicated by a solid-line circle). As shown in FIG. 10, all pixel data on the interpolation line are interpolated at a = 1/2 (b + c) by pixel data immediately above and below the pixel to be interpolated.

[0004]

When performing the above-described interpolation, all the pixel data in the line to be interpolated are
The pixel data is converted by two pixel data on the line immediately above and below the line, respectively. As shown in FIG. 10, for example, when the gradient A of the similar color is not perpendicular to the pixel data to be interpolated, such as an outline, the interpolated pixel data is on the gradient A of the similar color shown in FIG. 10. It should be interpolated at two points.

[0005] Nevertheless, when the above-described interpolation is performed, since the interpolation is not performed using the pixel data on the gradient A of the similar color, color blur occurs and the display quality deteriorates. Therefore, an object of the present invention is to provide an image processing method and apparatus capable of reducing color blur and the like and improving display quality.

[0006]

According to a first aspect of the present invention, in generating an interpolation line, a plurality of directions on a line positioned above and below the interpolation line are determined with respect to an interpolation pixel to be generated. Are compared with each other to detect inclinations of similar colors, and an interpolation pixel is generated using a pixel having an optimal inclination.

According to the image processing method of the present invention, the inclination of similar colors is detected from pixels in a plurality of directions on a line located above and below the interpolation line, and interpolation is performed using a pixel on the optimal inclination. Since pixels are generated, color blur etc. can be reduced,
The display quality can be improved. The image processing apparatus according to claim 2, wherein the memory, an interlace signal storage circuit that inputs an interlace signal and stores the image data in the memory, and a memory that is stored in the memory when generating a pixel on an interpolation line. A pixel comparison circuit that compares pixel data in a plurality of directions of a line connecting upper and lower pixels with respect to an image having an interpolation line based on the image data, and detects a direction in which the comparison value is minimum as a gradient of a similar color, An interpolation circuit that performs line interpolation based on the inclination information of the pixel comparison circuit, and a non-interlace signal output circuit that outputs a non-interlace signal to a display device based on the interpolation data of the interpolation circuit.

According to the second aspect of the present invention, in the generation of the interpolation line, a comparison circuit for detecting the inclination of the similar color is provided from the pixel data on the lines located above and below the interpolation line, 2 to be used on the slope
Since the interpolation data is generated from the pixel data of the points and output to the display device, when converting the image data of the interlaced signal into a non-interlaced signal, color blur and the like can be reduced, and the display quality can be improved. .

[0009] The image processing apparatus according to the third aspect is the second aspect.
In, the memory stores the image data of the field currently being interpolated and the image data of the temporally previous field,
The pixel comparison circuit generates pixel data on the interpolation line based on the image data of the field currently being interpolated and stored in the memory. Among the comparison values to be compared and the comparison values comparing the pixel data in a plurality of directions at the same place as the pixel currently being interpolated of the image data of the temporally previous field stored in the memory, the direction in which the minimum direction is the same color This is detected as an inclination.

According to the third aspect of the present invention, the line to be interpolated is detected by detecting an appropriate gradient of the same color from the pixel information of the immediately preceding field at the same position as the pixel currently being interpolated. This can improve the detection accuracy of detecting an appropriate similar-color inclination at the time of pixel generation, and is particularly effective in line interpolation of image data having minute changes.
According to a fourth aspect of the present invention, in the image processing apparatus according to the second aspect, a comparison value obtained by comparing pixels adjacent in the line direction of the image data in the memory is compared with a threshold value. And a line comparison circuit for enhancing the outline of the image data by adding or subtracting the pixel data. The pixel comparison circuit inputs the image data of the line comparison circuit.

According to the image processing device of the present invention, the inclination information from the pixels of the lines located above and below the interpolation line and the result of the comparison of the adjacent pixels in the line direction can be used.
In order to enhance the contour and the interpolation pixel on the contour, in addition to the same effect as in the second aspect, the adjacent pixels in the line direction are compared, and the contour is enhanced by comparison with the set threshold value of the contour enhancement. Therefore, in general, even when an interlaced signal having a coarse image quality is converted into a non-interlaced signal and displayed, deterioration of the image quality is not noticeable.

According to a fifth aspect of the present invention, in the image processing apparatus according to the second, third or fourth aspect, the pixel data has luminance data and chrominance data, and the pixel comparison circuit compares the luminance data. It is. According to the image processing apparatus display of the fifth aspect, in addition to the same effects as those of the second, third or fourth aspect, the interpolation line is used for the luminance data and the color difference data of the interlace signal stored in the memory. In detecting the inclination of the similar color at the time of generation, the inclination detection processing is performed only from the luminance data, so that the circuit scale and the processing time can be reduced.

According to a sixth aspect of the present invention, there is provided an image processing apparatus comprising: a memory; an image data storage circuit for storing input image data in the memory; Based on the image data stored therein, pixel data in a plurality of directions of lines above and below the interpolation line are compared to detect a direction in which the comparison value is minimum as a gradient of a similar color, and in the case of reduction processing, the direction of the interpolation line A pixel comparison circuit that compares pixel data before interpolation and pixel data in a plurality of directions of lines above and below the interpolation line and detects a direction in which a comparison value is minimum as a gradient of a similar color;
In the case of enlargement processing, line interpolation is performed based on the inclination information of the pixel comparison circuit, and in the case of reduction processing, image data to be interpolated is generated from pixel data before interpolation and a plurality of pixel data on the inclination of a similar color to the interpolation. And an output circuit for outputting image data enlarged or reduced by the enlargement / reduction interpolation circuit.

According to the image processing apparatus of the sixth aspect, the same effects as those of the first aspect can be obtained.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment according to the present invention will be described with reference to FIGS.
FIG. 1 is a configuration example of a display controller which is an image processing device that converts an interlaced signal into a non-interlaced signal. In FIG. 1, an interlace signal storage circuit 1 receives an interlace signal as input, and stores luminance data and color difference data as pixel data in a memory 2.
A memory 2 for storing pixel data of the interlace signal storage circuit 1, a pixel comparison circuit 3 for comparing the stored pixel data inside the memory 2, and a pixel comparison circuit 3
And a non-interlaced signal output circuit 5 that outputs a non-interlaced signal based on the interpolated data.

In generating the pixel d on the interpolation line, the pixel comparison circuit 3 uses the pixel data stored in the memory 2 as shown in FIG. Pixel data of a certain line (indicated by a solid circle) is compared, and a comparison value (for example, a difference value) of two pixels in a plurality of directions L _{1 to} L ₇ connecting pixels of a line above and below the pixel d. Extracts the direction of the smallest inclination. Also, the number of directions in the comparison direction is not limited to seven, and can be arbitrarily increased or decreased.

The interpolation circuit 4 generates pixel data to be interpolated from the pixel data of the two points having the smallest comparison value. Method for generating pixel data to be interpolated is the same as the prior art example, if the pixel data p of up and down in that direction with the inclination direction L ₅ of similar colors, when q, with d = (1/2) (p + q) Ask. All pixels on the interpolation line are generated as described above.

In this display controller, the image data of the even field of the interlaced signal is obtained by interpolating the odd line by the method described above, and the image data of one frame is obtained by interpolating the even line as the image data of one frame. The image data is interpolated, converted into RGB data by the non-interlace signal output circuit 5 as one frame of image data, and output to the display device.

An image processing method using this display controller will be described. In generating an interpolation line, an interpolation pixel to generate an interpolation line is defined by a plurality of directions in lines above and below the interpolation line. The purpose of the present invention is to detect the inclination of similar colors by comparing pixels, and to generate an interpolated pixel using a pixel having an optimal inclination. According to this embodiment, when converting image data of an interlaced signal into a non-interlaced signal, the inclination of similar colors is detected,
By generating the interpolation data, color blur and the like can be reduced, and display quality can be improved.

A second embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a configuration example of a display controller that converts an interlaced signal into a non-interlaced signal. In FIG. 3, an interlace signal storage circuit 1 for inputting an interlace signal, a memory 6 for storing image data of a field currently being interpolated and an image data of the immediately preceding field, and an internal storage of the memory 6 A pixel comparison circuit 7 for comparing the pixel data obtained by the interpolation and an interpolation circuit 4 for interpolating the data based on the result of the pixel comparison circuit 2
And a non-interlace signal output circuit 5 for outputting a non-interlace signal based on the interpolation data.

The pixel comparison circuit 7 has the function of detecting the inclination of similar colors described in FIG. 2 of the first embodiment and the function described using FIG. In FIG. 4, (a) is the previous image data, that is, the image data of the field 1/60 seconds before in time, (b) is the image data of the field currently being interpolated, Shows the pixels on the interpolation line. As for the pixel e in the line that is currently being interpolated, a pixel f exists as input pixel data at the same position as the pixel e in the field 1/60 second earlier in time. With respect to the pixel to be currently interpolated, the pixel data of the previous field at the same position as the pixel to be interpolated in the direction of the gradients L _{1 to} L ₇ of similar colors shown in FIG. Compare the pixel data of the line above and below the line,
Extract the minimum slope of the comparison value. In other words, the pixel data of the immediately preceding field is compared in the same way as the current pixel data, and the minimum slope is selected from both the current and previous comparison values. For example, as a result of comparing two pixels in a plurality of directions L _{1 to} L ₇ connecting pixels on upper and lower lines passing through the pixel e, the comparison value between L ₃ and L ₇ becomes minimum, and e = ( (１ ／) (g + h) or (１ ／) (i
+ J). If a plurality of similar color gradients are detected by comparing the minimum values, the pixel e is temporally shifted by 1 /
By using the pixel f at the same location 60 seconds before, f is compared with (1/2) (g + h) or (1/2) (i + j), and the minimum value is determined as the slope of the similar color. That is, when the comparison between f and (1/2) (g + h) is the minimum, e = (1 /
2) Interpolated by (g + h). Further, the number of directions to be compared can be arbitrarily increased or decreased.

The interpolation circuit 4 determines the gradient of the similar color that minimizes the sum of the two comparison results, and generates pixel data to be interpolated from the pixel data at two points on the gradient. In this display controller, the image data of the even field of the interlaced signal is interpolated on the odd line by the above-described method, and as image data of one frame, the image data of the odd field is interpolated on the even line. The image data of one frame is converted into RGB by the non-interlace signal output circuit 5 and output to the display device. In addition, components having the same reference numerals as those in the first embodiment have common functions.

According to this embodiment, in the line interpolation of image data having minute changes, only the first embodiment has an accuracy of detecting an appropriate gradient of similar colors at the time of generating a pixel of a line to be interpolated. Since the drop occurs, the detection accuracy can be improved by detecting an appropriate similar color gradient from the pixel information of the immediately preceding field at the same position as the pixel currently being interpolated.

A third embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a configuration example of a display controller that converts an interlaced signal into a non-interlaced signal. As compared with the circuit configuration of the first embodiment of the first embodiment, a line comparison circuit 8 is inserted between the memory 2 and the pixel comparison circuit 3 as shown in FIG. This is the same as the embodiment.

FIG. 6 shows the configuration and function of this line comparison circuit 8.
This will be described with reference to FIG. In FIG. 6, the adjacent pixel comparison circuit 9
Compares a value (for example, a difference value) obtained by comparing pixels adjacent in the line direction with an externally set threshold value for contour enhancement, and outputs the result. When the comparison value of the pixel data is larger than the threshold value, the selection circuit 10 selects an offset value input from the outside, and the adder / subtractor 11 adds or subtracts the image data by the offset value. At this time, the offset value is added or subtracted by an arbitrary value depending on the positional relationship and the magnitude relationship between the two compared pixels. On the other hand, if it is smaller than the threshold value, that is, if it is determined that it is not the outline of the image,
0 outputs a "0" input, that is, line data as it is.

The image data whose outline has been emphasized by the line comparison circuit 8 is subjected to the processing of the pixel comparison circuit 3 and subsequent steps described with reference to FIG. According to this embodiment, in general, when an interlaced signal having a coarse image quality is converted into a non-interlaced signal and displayed, the deterioration of the image quality is conspicuous. By comparing with an emphasis threshold, outline emphasis can be performed. In addition, there are effects similar to those of the first embodiment.

A fourth embodiment according to the present invention will be described with reference to FIG. FIG. 7 is a configuration example of a display controller that converts an interlaced signal into a non-interlaced signal. With respect to the circuit configuration of the first embodiment,
As shown in FIG. 7, instead of the pixel comparison circuit 3 shown in FIG.
The pixel data is replaced by a pixel comparison circuit 12 that determines the inclination of similar colors from the luminance data Y in the pixel data.

The method of detecting the inclination is the same as that of the pixel comparison circuit 3 described in the first embodiment, but the inclination of the similar color is determined only from the luminance data Y of the luminance data Y and the color difference data C. Due to the circuit configuration, the circuit can be reduced in scale and the processing speed can be increased. In addition, there are effects similar to those of the first embodiment. This embodiment can be applied to the second embodiment and the third embodiment.

A fifth embodiment of the present invention will be described with reference to FIG. This embodiment is an application example of the first embodiment corresponding to claim 1, and is a configuration example of a display controller that enlarges and reduces image data stored in the memory 14 as shown in FIG. . FIG.
, An image data storage circuit 13 for storing input image data in a memory 14, a memory 14 for storing image data, a pixel comparison circuit 15 for comparing stored pixel data inside the memory 14, The display controller includes an enlargement / reduction interpolation circuit 16 that interpolates the enlargement or reduction of image data in the line direction based on the result of the circuit 15 and an output circuit 17 that outputs enlarged or reduced image data.

On the basis of the image data stored in the memory 14, the pixel comparison circuit 15
The inclination of similar colors is determined by the method shown in FIG. 2 of the first embodiment. During the reduction process in the line direction, as shown in FIG. 9, when the I line is deleted from the five lines G, H, I, J, and K, all the pixel data of the H line are G, I,
The pixel data of the line is interpolated, and all the pixel data of the J line are interpolated by the pixel data of the I and K lines. In the interpolation of the H line, as shown by the pixel h to be interpolated in FIG. 10, three pixel data on the gradient of similar colors in the directions L _{1 to} L ₇ are compared, and the comparison value of the three pixels is the minimum. Detect the inclination of similar colors. The number of directions to be compared can be arbitrarily increased or decreased.

Similarly, the optimum inclination of similar colors is detected for all pixel data of the J line. The data after the interpolation of the H line is h '= 1/3 (g + h + i). h '
Is the pixel data after interpolation, g is the pixel data on the G line on the slope of the detected similar color, i is the pixel data on the I line on the slope of the detected similar color, and h is the pixel data before the interpolation. Represents pixel data on the H line.

In the case of enlargement, the enlargement / reduction interpolation circuit 16 generates the pixel data of the interpolation line from the pixel data of two points of the same color gradient. In the case of reduction, pixel data to be interpolated is generated based on a total of three pixel data of pixel data before interpolation and pixel data of two points on the slope of a similar color, and a line to be deleted is deleted. The enlarged or reduced image data is output from the output circuit 17 to the display device.

The pixel comparison circuit 3 according to the first embodiment or the like determines the slope of the similar color from only the two lines above and below when generating the interpolation line. Needless to say, by increasing the number, the accuracy of detecting the inclination of similar colors is improved. The input signal in the first embodiment and the like is a Y / C signal, but it goes without saying that the input signal is compatible with all data formats as long as it is an interlace signal input.

The interlaced signal output circuit 5 of the first embodiment or the like is an RGB output, but it goes without saying that the output is in a data format suitable for the display device. Also,
The interpolation circuit 4 according to the first embodiment or the like sets the ratio of adding two pixels on the slope of the similar color to 0.5: 1 in the generation of the interpolation data. Needless to say, it is possible to change the ratio to be performed.

The pixel comparison circuit 7 of the second embodiment
In the above, the inclination of the similar color was determined only from the pixel data of one frame before which is temporally 1/60 second earlier, but by increasing the number of temporally previous fields used for the inclination determination, the similar color It is needless to say that the inclination detection accuracy is improved. In the line comparison circuit 8 according to the third embodiment, the outline of the image data is determined only from the comparison values of the pixel data adjacent in the line direction. Needless to say, the detection accuracy of the outline of the image data is improved.

The pixel comparison circuit 1 according to the fourth embodiment
2, among the Y / C data of the interlace signal,
Although the inclination of the similar color is determined only from the luminance data, it goes without saying that only the luminance data is used after converting the image data input in another data format into Y / C data. Further, the pixel comparison circuit 15 of the fifth embodiment determines the slope of the similar color from only the two lines above and below the line to be interpolated in the reduction in the line direction. It goes without saying that increasing the number improves the inclination detection accuracy of similar colors.

[0037]

According to the image processing method of the first aspect,
Detects gradients of similar colors from pixels in multiple directions on a line located above and below the interpolation line, and generates interpolation pixels using pixels on the optimal gradient, reducing color blur and the like, and improving display quality. Can be improved.

According to the second aspect of the present invention, in generating the interpolation line, a comparison circuit for detecting the inclination of the similar color is provided from the pixel data on the lines located above and below the interpolation line, 2 to be used on the slope
Since the interpolation data is generated from the pixel data of the points and output to the display device, when converting the image data of the interlaced signal into a non-interlaced signal, color blur and the like can be reduced, and the display quality can be improved. .

According to the third aspect of the present invention, the line to be interpolated is detected by detecting an appropriate gradient of a similar color from the pixel information of the immediately preceding field at the same position as the pixel currently being interpolated. This can improve the detection accuracy of detecting an appropriate similar-color inclination at the time of pixel generation, and is particularly effective in line interpolation of image data having minute changes.
According to the image processing device of the fourth aspect, the contour enhancement and the interpolation pixel on the contour are determined based on the inclination information from the pixels of the lines positioned above and below the interpolation line and the result of the comparison of the adjacent pixels in the line direction. In addition to the effect similar to that of the second aspect, in addition to the effect similar to that of the second aspect, since the adjacent pixels in the line direction are compared with each other and the outline is enhanced by comparing with a set threshold value of the outline enhancement, generally, the interlacing with coarse image quality is performed. Even when a signal is converted into a non-interlaced signal and displayed, deterioration in image quality is not noticeable.

According to the image processing apparatus display of the fifth aspect, in addition to the same effects as those of the second, third or fourth aspect, the luminance data and the chrominance data of the interlaced signal stored in the memory can be obtained. In detecting the inclination of similar colors at the time of generating the interpolation line, the inclination detection processing is performed only from the luminance data, so that the circuit scale and the processing time can be reduced.

According to the image processing apparatus of the sixth aspect, the same effects as those of the first aspect can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a display controller that is an image processing method and apparatus according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating a method of detecting the inclination of similar colors in the pixel comparison circuit.

FIG. 3 is a configuration diagram of a display controller according to a second embodiment of the present invention.

FIG. 4 is an explanatory diagram of the pixel comparison circuit.

FIG. 5 is a configuration diagram of a display controller according to a third embodiment of the present invention.

FIG. 6 is a configuration diagram of the line comparison circuit.

FIG. 7 is a configuration diagram of a display controller according to a fourth embodiment of the present invention.

FIG. 8 is a configuration diagram of a display controller according to a fifth embodiment of the present invention.

FIG. 9 is an explanatory diagram of a reduction method by deleting the line.

FIG. 10 is an explanatory diagram illustrating a method of generating interpolation data according to a conventional method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Interlace signal storage circuit 2 Image data storage memory 3 Pixel comparison circuit 4 Interpolation circuit 5 Non-interlace output circuit 6 Image data storage memory 7 Pixel comparison circuit 8 Line comparison circuit 9 Adjacent pixel comparison circuit 10 Selection circuit 11 Addition / subtraction unit 12 pixel comparison circuit 13 image data storage circuit 14 image data storage memory 15 pixel comparison circuit 16 scaling interpolation circuit 17 output circuit

Claims (6)

[Claims] When generating an interpolation line, a pixel in a plurality of directions on a line located above and below the interpolation line is compared with an interpolation pixel to be generated of the interpolation line to determine a gradient of a similar color. An image processing method comprising: detecting and generating an interpolated pixel by using a pixel on an optimum inclination. 2. A memory, an interlace signal storage circuit for inputting an interlace signal and storing the image data in the memory, and the image data stored in the memory when generating a pixel on an interpolation line. A pixel comparison circuit that compares pixel data in a plurality of directions of a line connecting upper and lower pixels with respect to a certain pixel of the interpolation line based on the interpolation line and detects a direction in which the comparison value is minimum as a gradient of a similar color,
An image processing apparatus comprising: an interpolation circuit that performs line interpolation based on inclination information of the pixel comparison circuit; and a non-interlace signal output circuit that outputs a non-interlace signal to a display device based on interpolation data of the interpolation circuit. 3. A memory for storing image data of a field currently being interpolated and image data of a temporally previous field, and a pixel comparing circuit which is stored in the memory when generating a pixel on an interpolation line. A comparison value for comparing pixel data in a plurality of directions of a line connecting upper and lower pixels to a certain pixel of the interpolation line based on the image data of the field currently being interpolated, and a temporally preceding value stored in the memory. 3. The image processing apparatus according to claim 2, wherein the direction in which the pixel data in the plurality of directions at the same position as the pixel currently being interpolated in the field image data is compared has a minimum direction as a slope of a similar color. . 4. A method for comparing a comparison value obtained by comparing pixels adjacent in a line direction of image data in a memory with a threshold value and adding or subtracting an offset value to the image data when the comparison value is large. 3. The image processing apparatus according to claim 2, further comprising a line comparison circuit for enhancing the contour of the image data, wherein the pixel comparison circuit inputs image data of the line comparison circuit. 5. The image processing apparatus according to claim 2, wherein the pixel data has luminance data and color difference data, and wherein the pixel comparison circuit compares the luminance data. 6. A memory, an image data storage circuit for storing input image data in the memory, and a pixel stored in the memory for generating a pixel on an interpolation line in a case of an enlargement process in a line direction. Based on image data, pixel data in a plurality of directions of lines above and below the interpolation line are compared to detect a direction in which the comparison value is minimum as a slope of a similar color, and in the case of reduction processing, a pixel before interpolation of the interpolation line A pixel comparison circuit that compares data and pixel data in a plurality of directions of lines above and below the interpolation line to detect a direction in which a comparison value is minimum as a slope of a similar color, and a pixel comparison circuit in the case of the enlargement processing. Performs line interpolation based on tilt information and in the case of reduction processing Generates and deletes image data to be interpolated from pixel data before interpolation and multiple pixel data on the same color gradient An image processing apparatus comprising: a scaling interpolation circuit for deleting a target line; and an output circuit for outputting image data enlarged or reduced by the scaling interpolation circuit.