JP2002014667A - Image compositing and processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image compositing and processing device not uselessly deteriorating the quality of a graphic image by controlling processing graphic image data by filtering also using a compositing coefficient. SOLUTION: The image compositing and processing device 1 having a filtering execution control part 33 for controlling filtering in a filtering part 3 for processing a graphic image by filtering and outputting it, and compositing graphic image data outputted from the filtering part 3 and externally inputted video image data by an image compositing part 8 according to the compositing coefficient stored in a setting register part 5 is provided with a coefficient comparison part 6 for comparing a set compositing coefficient with a threshold and outputting a comparison result, and the filtering execution control part 33 controls processing the graphic image data by filtering based on the output from the coefficient comparison part 6 in addition to the setting for executing the processing by filtering.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image synthesizing apparatus for synthesizing graphics image data and other image input data at an arbitrary ratio and outputting the synthesized image data to a display or the like. The present invention relates to an image synthesis processing apparatus including a filter processing unit for reducing line flicker of a generated graphics image.

[0002]

2. Description of the Related Art Conventionally, there is known an image synthesizing processor for synthesizing graphics image data and other image input data at an arbitrary ratio and outputting video to a display or the like in an interlaced manner. In order to reduce the line flicker of the graphics image generated when outputting video in the above-mentioned manner, the video data of two vertical lines (two adjacent lines having different fields) of the graphic image before synthesis is filtered between fields. 2. Description of the Related Art There is known an image synthesizing processing device including a filter processing unit that outputs a processed image.

FIG. 6 is a block diagram showing a configuration of a conventional image synthesis processing device. Image synthesis processing device 91 in FIG.
Includes a graphic image data generation unit 2 that generates video data of a graphic image configured using a specific data format, a filter processing unit 93 that performs a filtering process on the graphic image data, and outputs the result. The control unit 4 controls the contents set in the setting register unit 95 and controls the operation of each unit in the image synthesizing processing unit 91, and various settings relating to the operation of the filter processing unit 93 and the synthesis coefficient of graphic image data and input image data. A setting register unit 95 for storing settings, an image synthesizing unit 8 for synthesizing graphic image data output from the filter processing unit 93 and input image data in accordance with a synthesis coefficient set in the setting register unit 95, and an external image The image data input unit 9 to which data is input and the image data And an image data output section 10 for image data is output.

[0006] In a filter processing unit 93, a filter unit 31 that performs filtering between fields on video data of two vertical lines of a graphic image and outputs the result, and a filter process of the filter unit 31 are executed. It has a filter processing execution control unit 32 for switching whether or not the processing is performed.

In the setting register section 95, the filter processing execution control section 32 in the filter processing section 93 is turned ON / OFF.
Filter execution setting unit 5 for storing settings for switching OFF
4 and a combination coefficient setting unit 51 for storing setting of combination coefficients of graphic image data and input image data to be combined by the image combination unit 8.

Next, the operation of the conventional image synthesis processing device 91 will be described. The graphic image data generated by the graphic image data generation unit 2 is input to the filter unit 31 in the filter processing unit 93. Filter unit 31
Determines whether or not to execute the filtering process on the graphic image data input in accordance with the instruction of the filtering process execution control unit 32. If the instruction from the filter processing execution control unit 32 is an instruction to execute the filter processing, the filter processing is executed on the input graphic image data and output to the image synthesizing unit 8. If the instruction is an instruction not to execute the filter processing, the input graphic image data is output to the image synthesizing unit 8 without executing the filter processing.

The filter execution control unit 32 is switched according to the contents set in the filter execution setting unit 54 in the setting register unit 95, and the filter execution setting unit 5
4 can be rewritten by the control unit 4.

The image synthesizing section 8 converts the video image data input from the image data input section 9 and the graphic image data input from the filter section 31 in accordance with the contents set in the synthesis coefficient setting section 51 in the setting register section 95. The combined image data is output to the image data output unit 10.

Further, the setting contents of the synthesis coefficient setting section 51 are as follows.
It can be rewritten by the control unit 4 similarly to the filter execution setting unit 54.

By the way, the above-mentioned filter processing unit 93
Is switching between two fields of video data of a graphic image by performing a filter process between fields and outputting the processed data, for the following reason.

[0011] By executing the filtering process on the graphic image, line flicker of the graphics image can be reduced. However, in exchange for this, the image quality of the graphic image is degraded due to the filtering process. Therefore, when the graphic image displayed on the display is confirmed, for example, when the occurrence of line flicker that occurs when the graphic image is output as a video in the interlaced mode is small, and the image quality deterioration due to the filter processing is remarkable, In some cases, a graphic image not subjected to the filtering process is easier to see.

For this reason, in the conventional image synthesizing apparatus 91, the occurrence state of the line flicker is confirmed in advance from the graphic image displayed on the display, and the filter execution setting section 54 in the setting register section 95 using the control section 4. By adjusting the setting, the filter processing execution control unit 32 in the filter processing unit 93 is switched to switch between execution (ON) and non-execution (OFF) of the filter processing on the graphic image data.

As described above, the conventional image synthesizing processing device 91 for performing the operation of synthesizing the image with another video input image input from the outside and displaying the image on the display is provided by the control unit 4 for processing the image data of graphics. , Image memory unit 4
1, and a memory control processing unit 42 for controlling the image memory unit 41, reads out the graphics image data stored in the image memory unit 41 at a predetermined video timing, and Neighboring graphics image data with different corresponding fields
By simultaneously reading data from the image memory and performing filtering between fields, line flicker of a graphics image generated when the video output method is the interlace method has been reduced.

In the conventional image synthesis processing device 91,
The image ratio of the video image synthesized using the coefficient value is set in advance in the synthesis coefficient setting unit 51 in the setting register unit 51 as the synthesis coefficient α, which is the ratio of the synthesis of the graphics image and the video input image from the outside. Was output.

[0015]

As described above, in the conventional image synthesizing processing apparatus, line flicker is generated from a graphics image previously displayed on a display in order to obtain an image synthesized output which is easy for a user to see. After confirming the situation, the graphic processing unit 9 filters the graphic image data.
It is necessary to switch whether or not to execute the filtering process in 3 by setting the filter execution setting unit 54 in the setting register unit 95 by the control unit 4.

Further, for example, in order to omit the above setting, the filter execution setting section 54 in the setting register section 95 is set so that the filter processing section 93 always executes the filtering process on the graphic image data. However, in that case, the graphic image data is always deteriorated.

By the way, the image synthesizing apparatus synthesizes graphic image data and input image data, and when the ratio of graphic image data in the image data is small, line flicker of the graphic image becomes less noticeable. Has characteristics. Therefore, when the filter execution setting unit 54 is set by checking the occurrence state of the line flicker from the graphics image previously displayed on the display as described above, the graphic image data in which the line flicker is inconspicuous is set. However, there is a problem that not only the setting is useless, but also the image quality of the graphic image data is unnecessarily deteriorated by the setting.

The present invention has been made in order to solve the above-mentioned conventional problems, and is not limited to ON / OFF of a filtering process according to the type of a graphic image, but is adapted to a synthesis ratio of graphic image data. It is an object of the present invention to provide an image synthesis processing device which does not degrade the quality of a graphics image by executing a filtering process on graphic image data.

[0019]

In order to achieve the above object, an image synthesizing processing apparatus according to the present invention as defined in claim 1 comprises:
A graphic image data generating unit for generating video data of a graphic image;
A filter processing unit that performs filtering between fields on the video data for the lines and outputs the processed data, and synthesizes graphic image data output from the filter processing unit and video image data input from the outside according to a set synthesis coefficient. An image synthesizing unit, a setting register unit for storing a setting for executing the filter processing and a setting of a synthesis coefficient for the graphic image data and the image data, and a control unit for controlling the setting and control of each unit. An image synthesizing processing apparatus having a filter processing execution control unit configured to control a filtering process based on at least a setting for executing the filtering process in the filtering unit, wherein the set synthesis coefficient and a predetermined threshold value are set. A coefficient comparison unit that compares the value with a value and outputs a comparison result, wherein the filter processing execution control unit includes: In addition to setting for executing serial filtering, based on the output of the coefficient comparison unit, which comprises carrying out the control for executing the filter processing for the graphic image data.

According to a second aspect of the present invention, in the image synthesizing processing apparatus according to the first aspect, the setting register unit includes a threshold value setting unit that sets the threshold value according to an instruction from the control unit. It is characterized by.

According to a third aspect of the present invention, in the image synthesizing apparatus according to the second aspect, the setting register unit sets an upper limit value of the threshold value in accordance with an instruction from the control unit. A coefficient comparison unit, wherein the coefficient comparison unit compares the combined coefficient with a threshold value set in the threshold value setting unit, and sets the combined coefficient and the threshold value upper limit setting unit. And outputting both of the comparison result obtained by comparing the threshold value to the filter processing execution control unit.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on illustrated embodiments. Embodiment 1 FIG. FIG. 1 is a block diagram illustrating a configuration of an image composition processing apparatus according to Embodiment 1 of the present invention. In FIG. 1, parts having the same functions as those of the conventional image synthesizing processing apparatus shown in FIG. 6 are denoted by the same reference numerals, and redundant description will be omitted.

The main difference between the image synthesizing processor 1 shown in FIG. 1 and the conventional image synthesizing processor 91 shown in FIG.
A coefficient comparison unit 6 that receives the synthesis coefficient α output from the synthesis coefficient setting unit 51 and receives a fixed threshold value, compares both inputs, and outputs a comparison result as a control signal; A threshold value storage unit 7 for storing a threshold value of a fixed value input to the comparison unit 6; and a filter processing execution control unit 3 in the filter processing unit 3.
3 inputs a control signal output from the coefficient comparing unit 6 as a parameter, and performs additional control over the control based on the setting stored in the filter execution setting unit 54 in order to execute the filtering process on the graphic image data. It is a point to be implemented.

Next, the operation of the image composition processing apparatus 1 will be described. First, the control unit 4 determines the synthesis ratio of the graphics image and the externally input image, and sets the synthesis coefficient α in the synthesis coefficient setting unit 51. The synthesis coefficient α is, for example, from 0 to 2 when it has an 8-bit value.
Values in the range up to 55 can be taken. Coefficient comparison unit 6
When the synthesis coefficient α (hereinafter referred to as α) is input, the fixed value threshold N (N is a value in a range from 0 to 255) stored in the threshold storage unit 7 in advance. An integer that takes a value is read and compared, and the comparison result is output to the filter execution control unit 33 as a control signal (1 bit). As the comparison logic at this time, for example, when α <N, “1” is output, and when α ≧ N, “0” is output.

When the control signal (comparison result) output from the coefficient comparison unit 6 is input to the filter processing execution control unit 33, the filter unit 31 uses the control result based on the comparison result for two vertical lines of the graphic image. Whether video data is subjected to inter-field filtering and output (ON / OFF) is controlled based on the following logic.

In the control in this case, the filter unit 3
The operation of the filter processing itself in 1 is the same as the conventional one, but the result of comparison from the coefficient comparing unit 6 is added to the determination as to whether or not to perform the filter processing and output.

The specific control contents of the filter unit 31 are as follows. When filter processing is not performed based on the control content set in the filter execution setting section 54 in the setting register section 5 (OFF), the filter section 31 does not perform the filter processing as in the related art, but outputs the graphic image data. Output as is. However, when the filtering process is performed based on the control content set in the filter execution setting unit in the setting register unit 5 (ON), the filtering process is continuously performed by the filter unit 31 during the ON period. Instead, even during that ON, the coefficient comparing unit 6
The filter processing execution control unit 33 controls the ON / OFF of the filter processing by a separate logic according to the control signal from.

For example, if the control signal from the coefficient comparing section 6 is "0", filter processing is performed, and if the control signal is "1", image data is output as it is without performing filter processing. And By controlling the filter processing execution control unit 33 in this manner, even if the filter execution setting unit 54 in the setting register unit 5 is set to perform the filter processing, the input is input from the coefficient comparison unit 6. Filter unit 31 depending on the content of the control signal
Does not perform the filtering process. In the present embodiment, as described above, adaptive filter processing can be performed based on the synthesis coefficients.

Here, the graphic image data on which the filtering process is performed in the first embodiment will be described in more detail.

FIG. 2 is a block diagram showing the configuration of the image synthesizing processing apparatus 1 of FIG. 1 in more detail. In FIG. 2, the internal configuration of the graphic image data generation unit 2 and the configuration between the filter processing unit 3 and the image synthesis unit 8 are specifically added.

First, in the internal configuration of the graphic image data generator 2, the image memory 41 stores graphics image data defined in various formats. The memory control processing unit 42 simultaneously reads out the graphics image data between the fields from the image memory unit 41 using the real-time control signal generated by the timing signal generation unit 45 as a reference timing. First FI in memory unit 43
The FO unit 61 and the second FIFO unit 62 store graphics image data between fields read from the memory control processing unit 42, respectively. Synchronous signal input unit 44
Inputs a clock signal from the outside, various horizontal / vertical synchronization signals, and the like.

The timing signal generation section 45 generates a desired video timing signal and various control signals from the various synchronization signals input. The multiplexer unit 46 performs multiplex processing on the inter-field graphics image data read from the first FIFO unit 61 and the second FIFO unit 62. The color information table storage unit 47 has a function as a memory to which the image data output from the multiplexer unit 46 is input as an address and outputs graphics image data (RGB 4: 4: 4) corresponding to the address. . The demultiplexer unit 48 separates the graphics image data (RGB 4: 4: 4) output from the color information storage unit 47 into data between fields again and outputs the data to the filter unit 31.

In the configuration between the filter processing unit 3 and the image synthesizing unit 8, the matrix processing unit 35 converts the graphics image data having the RGB format output from the filter processing unit 3 into the YCbCr format. The LPF / sub-sampling unit 36 outputs the graphics image data YCbCr 4: 4:
4 is converted to YCbCr 4: 2: 2 format, a low-pass filter process is performed on chroma data (Cb and Cr), and then a sub-sampling process is performed.

In FIG. 2, since the above configuration is additionally described, the following contents are also added to each unit of the image synthesis processing apparatus described in FIG. The control unit 4 includes an image memory unit 41 and a memory unit 4 for graphics image data.
3 is read and written, and data processing is performed. The setting register section 5 stores the operating conditions and the like of the signal generated by the timing signal generating section 45. The filter processing unit 3
Filtering between fields is performed on each data between fields output from the demultiplexer unit 48.
The image data input unit 9 receives video data (YC
bCr 4: 2: 2). A combination coefficient setting unit 51 provided in the setting register unit 5 sets a combination ratio between graphics image data output from the LPF / subsampling unit 36 and external video data input from the image data input unit 9. I do.

Next, the operation will be described based on each configuration of the image synthesizing processing apparatus of FIG. 2 which is more detailed than that of FIG. The graphics image data supported by the image synthesis processing device 1 has various data formats. In the following description, as an example, image data having a Clut (color information table) 8 graphics data format in which graphics image data per pixel is represented by 8 bits is output from an externally input ITU. -RBT-601: YC
bCr (4: 2: 2) video format (BT-601 format)
The operation will be described as an operation in a case where the video data is synthesized with video data having the same and output to the outside in the same video output format.

First, the control unit 4 for performing image data processing of the image synthesizing apparatus writes data to be displayed on the screen as a graphics screen in the image memory unit 41 in advance. When the video output format is the BT-601 format, a total of 720 x 480 x 8 bits of 720 horizontal pixels and 480 vertical lines per graphics screen to be displayed
Is secured in the memory as graphics image data.

Next, the timing signal generator 45 outputs the pixel clock (13.
5MHz) and horizontal and vertical synchronization signals
Generate a timing signal conforming to the -601 video signal format. Thereby, the horizontal / vertical frequency of the video signal, the timing of the blanking signal, and the like are generated in a form conforming to the standard. The timing signal generator 45 also generates a timing signal for reading the graphics image data from the image memory unit 41 and a video data output timing signal for outputting the graphics image data in the BT-601 format. . In this case, the setting parameters required for generating various timing signals are stored in the setting register unit 5.

The memory control processing section 42 reads out the image data stored in the image memory section 41 at high speed with a timing signal for each line in order to display the image data stored in the image memory section 41 on a display. . The timing signal in this case is the timing signal generation unit 45
Is the signal generated in. The high-speed reading in the case of the BT-601 format means that a frequency higher than the pixel clock frequency of 13.5 MHz, such as 27 MHz, is used as an operation clock of the image memory. As a method for reading data from the image memory unit 41, data is read as a pair of data between fields for each adjacent line.

Hereinafter, a method of reading data from the image memory unit 41 will be described with reference to the drawings. FIG.
It shows a method of reading data from the image memory unit 41, and is used when the memory control processing unit 42 reads two systems of data between fields from graphics image data stored in the image memory unit 41 of the image synthesis processing device. FIG.

For example, when the first line of the first field (the first line on the memory mapping: n = 1) is displayed on the display, the first line of the first field and the first line of the second field are displayed. Equivalent image data
(The first line: n = 1 and the second line: n = 2) of the image memory unit 41 are simultaneously read out in line units. Similarly, when the first line of the second field is displayed on the display, the first line of the second field is
The second line of the first field (the second line of the image memory unit 41)
The image data corresponding to the line: n = 2 and the third line: n = 3) is read out line by line. Each of the read image data is stored in the first F
The data is written into the IFO unit 61 and the second FIFO unit 62 at high speed using the operation clock of the memory.

The first FIFO unit 61 in the memory unit 43,
The adjacent image data having different fields stored in the second FIFO unit 62 is stored in the timing signal generation unit 4.
5 are simultaneously read out in synchronization with the pixel clock (13.5 MHz) using the timing signal for each line generated in 5.

The adjacent image data having different read fields is multiplexed in the multiplexer 46 by a clock (27 MHz) having twice the frequency component synchronized with the pixel clock. This allows
During one period of the 13.5 MHz pixel clock, two adjacent line image data having different fields are stored in the same manner.
It is multiplexed in synchronization with the frequency of MHz.

The multiplexed image data is input to the color information table storage unit 47 as an 8-bit address. The color information table storage unit 47 has a role as a RAM in which 256 × 24 Word graphics RGB (8 bits each for R, G, B) image data written in advance from the control unit 4 is stored, and an input address is inputted. , And outputs the graphics image data of 8 bits for each of RGB, that is, a total of 24 bits in synchronization with the 27 MHz clock. Through the color information table storage unit 47, for example, in the case of the Clut8 graphics image data format, an arbitrary 25
Six colors can be output as graphics images.

The digital image data of 8 bits each of RGB output from the color information table storage unit 47 is input to the demultiplexer unit 48, and is separated into adjacent image data having different fields again. For example,
Data RGB (n) (i) of the n-th line (n: 1 to 480, n is an integer) of the graphics image data stored in the image memory unit 41 (i indicates horizontal pixel positions 1 to 720) ) Is displayed on the display, the output from the demultiplexer unit 48 outputs RGB image data corresponding to two lines L1 and L2 shown below, Output in parallel with the pixel clock (13.5 MHz).

L1: RGB (n) (1), RGB (n) (2), RGB (n)
(3),..., RGB (n) (720) L2: RGB (n + 1) (1), RGB (n + 1) (2), RG
B (n + 1) (3),..., RGB (n + 1) (720) (However, when n = 720, n + 1 = 721 ≧ 720, L1 = L2 = RGB (720) (i)).

Each of the RGB image data between the fields output from the demultiplexer 48 is filtered by the filter processor 3.
, And the filtering process between the fields is performed by the filter unit 31 as described above, and the filtering process is not performed.

For example, input data to the filter processing unit 3 is RGB (n) (i) (n: 1 to 480, i: 1 to 720;
If n and i are integers, the filter unit 31 outputs the result calculated according to the following equation (1) as FRGB (n) (i).

When filter processing is performed (filter processing is ON): FRRGB (n) (i) = (RGB (n) (i) + RGB (n + 1) (i)) / 2 When filter processing is not performed (filter processing Is OFF): FRGB (n) (i) = RGB (n) (i) (1)

Here, whether or not to perform the above-described filtering (ON / OFF) on the output data from the filtering unit 31 in the filtering unit 3 is determined by the filtering execution control unit 3.
3 and a filter processing execution control unit 3
3 is controlled by the setting of the filter execution setting unit 54 in the setting register unit 5 set by the control unit 4.

The graphics image data FRGB (n) (i) output from the filter processing unit 3 is input to the matrix processing unit 35 and converted from RGB 4: 4: 4 data format to YCbCr 4: 4: 4 data format. Is done. The arithmetic expression for performing the matrix conversion process uses the arithmetic expression described in BT-601. As a result, the input image data of 8 bits each of RGB input to the matrix processing unit 35 is converted into the luminance and color difference image data of 8 bits of YCbCr and output from the matrix processing unit 35.

The YC output from the matrix processing unit 35
The graphics image data in the bCr 4: 4: 4 data format is input to the LPF / sub-sampling unit 36 to be converted into graphics image data in the YCbCr 4: 2: 2 data format. That is, YCbCr4:
By subjecting only the color difference data of each of Cb and Cr in the 4: 4 data format to low-pass filter processing and then performing sub-sampling processing, YCbCr 4:
Convert to 2: 2 data format.

The graphics image data in the YCbCr 4: 2: 2 data format (GYC (n) (i)) output from the LPF / subsampling unit 36 is output to the image synthesizing unit 8.
YCbC input to the image data input unit 9
r4: 2: 2 are combined with the external video input data (referred to as MYC (n) (i)), and the BT-
601: YCbCr 4: 2: 2 video output format (OYC
(n) and (i)).

The composition coefficient α defining the composition ratio in the image composition section 8 in this case is set in a composition coefficient setting section 51 provided inside the setting register section 5. For example, assuming that a combination coefficient α (hereinafter, referred to as α in the formula) is defined by 8 bits, video data to be combined is represented by the following formula (2).

OYC (n) (i) = (α / 255) × GYC (n) (i) + (1−α / 255) × MYC (n) (i) (2)

In the first embodiment, with the above-described configuration and operation, the graphics image data stored in the image memory unit 41 and the video image input from the outside to the image data input unit 9 are converted into a composite coefficient setting unit. 51, and outputs the synthesized image with the synthesis coefficient α set.
Regarding the filter processing between fields in the filter processing section 3, the filter execution setting section 54 of the setting register section 5
Is determined not only based on the content stored in the output image but also on the basis of the content stored in the synthesis coefficient setting unit 51, so that it is adapted to the output image of the display. Filter processing can be performed to reduce line flicker only when line flicker is conspicuous in the graphics image, and unnecessary image quality degradation due to filter processing when line flicker is not conspicuous can be reduced.

Embodiment 2 In the first embodiment, the generation of the control signal for adaptively performing the filtering process on the graphics image on the output image as described above includes the synthesis coefficient α
And a threshold value (fixed value), there are many types of graphics images, the occurrence of line flicker is different for each type, and each graphics image generated when synthesized with an external input image The occurrence of line flicker also depends on the value of the combination coefficient α. Therefore, it is desirable that the threshold value is not a fixed value but a variable value that can be arbitrarily changed. Therefore, an embodiment in which a parameter used for comparison with the synthesis coefficient α is not a fixed value but can be set to an arbitrary value from the control unit will be described below as a second embodiment.

FIG. 4 is a block diagram showing a configuration of the image synthesizing processing apparatus according to the second embodiment of the present invention. The main difference between the image synthesizing processing device 11 of FIG. 4 and the image synthesizing processing device 1 of FIG. 1 is that a threshold setting unit 15 52. In connection with the above, the coefficient comparing unit 16
Are configured to be input from a threshold setting unit 52 in addition to the input from the combination coefficient setting unit 51 in the setting register unit 15. Other configurations are the same as those in FIG. 1, and a description thereof will be omitted in FIG. 4.

The threshold value setting section 52 stores a threshold value set to an arbitrary value by the control section 4. As described above, the threshold value is adaptively set in advance to the composite image displayed on the display, based on the combination of the line flicker occurrence state of each graphics image and the value of the composite coefficient α.

Next, the operation of the image composition processing apparatus 11 according to the second embodiment will be described. The operation of the image synthesis processing device 11 other than the coefficient comparison unit 16 and the threshold value setting unit 52 is the same as the operation of the image synthesis processing device 1 in FIG. An operation different from the operation 1 will be described.

First, the operation of the synthesis coefficient setting unit 51 is the same as that of the first embodiment, and the synthesis coefficient α to be set is 8
Assume that it has a bit value. In that case, the threshold setting unit 5
2 has a function as a register that can arbitrarily set an 8-bit value from the control unit 4. Here, the threshold value set in the threshold value setting unit 52 is Nm (Nm is 0).
To 255), the coefficient comparing unit 16 inputs the composite coefficient α and the threshold value Nm, and compares the values of the two with the filter processing execution control unit 3.
3 is output as a control signal (1 bit).

In this case, the comparison logic is a combination coefficient α
<If the threshold value is Nm, “1” is output, and the combination coefficient α ≧
If the threshold value is Nm, “0” is output. Further, since the value of the threshold value Nm can be arbitrarily switched and set by the control unit 4, the control signal of the filter processing execution control unit 33 output from the coefficient comparing unit 16 is set to the value of the set threshold value Nm. It can be arbitrarily changed accordingly. Coefficient comparison unit 1
The control signal output from the filter unit 6 is input to the filter processing execution control unit 33, and the filter unit 3
1 is performed.

In the second embodiment, when the control signal for adaptively performing the filtering process on the output image is generated by the above configuration and operation, the threshold value Nm to be compared with the synthesis coefficient α is set to an arbitrary value. And the filter unit 31 performs the filtering process on the graphic image only when the synthesis coefficient α is equal to or more than the threshold value Nm, so that various types of graphics images and external input images can be set. Filter processing can be performed only when line flicker of the graphics image in the synthesized output image is conspicuous, corresponding to each graphics image generated when the graphics image is synthesized. Therefore, it is possible to reduce only the line flicker that is conspicuous in correspondence with various types of graphics images and each of the graphics images generated when the image is synthesized with the external input image, and to perform a filtering process when the line flicker is not conspicuous. This can reduce unnecessary deterioration of image quality.

Embodiment 3 In the second embodiment, as described above, a control signal for adaptively performing the filter processing is compared with the combination coefficient α and one variably settable threshold value, and each of the graphics images is Filter processing was performed to reduce the line flicker only when the line flicker was conspicuous.For example, if the graphics image occupies most of the display screen, the graphics processing may be performed even if the line flicker exists. There are cases where it is desired to give priority to the image quality of an image. Therefore, in order to cope with the case where the image quality is prioritized even when the line flicker is conspicuous, two thresholds, each of which is obtained by increasing the threshold to be compared by one in addition to the threshold of the second embodiment described above, are used. An embodiment configured so that filter processing can be set by comparing with a synthesis coefficient will be described below as a third embodiment.

FIG. 5 is a block diagram showing a configuration of the image synthesizing processing apparatus according to the third embodiment of the present invention. The main difference between the image synthesis processing device 21 of FIG. 5 and the image synthesis processing device 11 of FIG.
3 is the point. In connection with the above, in addition to the input from the composite coefficient setting unit 51 and the input from the threshold setting unit 52 in the setting register unit 15, the coefficient comparing unit 26 Is also input. The other configuration is the same as that of FIG. 4, and the description is omitted in FIG.

The threshold upper limit setting section 53 stores a threshold value set to an arbitrary value by the control section 4 similarly to the threshold setting section 52. This threshold is, as described above,
This corresponds to the combination coefficient α when the graphics image occupies most of the display screen of the display, and is set, for example, to be slightly smaller than the combination coefficient α in that case. The coefficient comparison unit 26 receives the combination coefficient α set by the combination coefficient setting unit 51 and the two threshold values set by the threshold setting unit 52 and the threshold upper limit setting unit 53, and inputs the combination coefficient α And each threshold value, and outputs the result of the comparison as a control signal.

Next, the operation of the image composition processing apparatus 21 according to the third embodiment will be described. The operation of the image synthesis processing device 21 other than the above-described coefficient comparison unit 26 and threshold upper limit setting unit 53 is the same as the operation of the image synthesis processing device 11 in FIG. Apparatus 1
An operation different from the operation 1 will be described.

First, the operations of the combining coefficient setting section 51 and the threshold setting section 52 are the same as in the second embodiment, and the combining coefficient α set in the combining coefficient setting section 51 has an 8-bit value. I do. In that case, the threshold upper limit setting unit 53
Has a function as a register in which the 8-bit value can be arbitrarily set from the control unit 4 like the threshold value setting unit 52. When the value set in the threshold upper limit setting unit 53 is a threshold Nl (Nl is an integer having a value in a range from 0 to 255, and the threshold Nl ≧ the threshold Nm),
The coefficient comparison unit 26 receives the synthesis coefficient α, the threshold value Nm, and the threshold value Nl, and outputs a comparison result between the synthesis coefficient α and each threshold value to the filter execution control unit 33 as a control signal (one bit each). I do.

The comparison logic at this time is a combination coefficient α
In case of <threshold value Nm, “1” is output and threshold value Nm
If ≦ synthesis coefficient α ≦ threshold value Nl, output '0',
If the combination coefficient α> threshold value Nl, “1” is output.
Further, the threshold value Nm and the threshold value Nl can be arbitrarily switched and set from the control unit 4, so that the coefficient comparing unit 26
Can be arbitrarily changed according to the set threshold values Nm and Nl. Coefficient comparison unit 26
Is output to the filter processing execution control unit 33, and the filter signal is output from the filter unit 3 as in the first embodiment.
1 is performed.

According to the third embodiment, when a control signal for adaptively performing a filtering process on an output image is generated by the above-described configuration and operation, a two-step threshold value to be compared with the synthesis coefficient α is used. Can be arbitrarily switched and set, so that it is possible to cope with the occurrence of line flicker of each of the various types of graphics images shown in the second embodiment and the graphics image at the time of composition. It is possible to deal with the case where priority is given.

In the third embodiment, the threshold value is described as having two levels. However, for example, the threshold value may be set to three or more levels so that the processing of the filter unit 31 can be performed more finely in accordance with the value of the synthesis coefficient α. It may be controlled.

[0071]

As described above, according to the first aspect of the present invention, the threshold for storing the combination coefficient for determining the combination ratio of the graphics image and the external input image and the threshold value (fixed value). A filter processing execution control unit in a filter processing unit that includes a value storage unit and a coefficient comparison unit that compares a synthesis coefficient with a threshold value, and uses the comparison result as a control signal to perform filter processing between fields of graphics image data Is controlled by the control signal, so that filter processing between fields for removing line flicker can be adaptively performed in accordance with the rate at which the graphics image data and the external input image are combined. For example, when line flicker is generally difficult to recognize, such as when the synthesis rate of a graphics image is low, the filter processing is not automatically performed. It is possible to perform the control. Therefore,
Only when line flicker of a graphics image is conspicuous, filter processing can be performed to perform adaptive line flicker removal.

According to the second aspect of the present invention, a threshold setting unit for setting an arbitrary value from the control unit is provided in the setting register unit, and the threshold set by the coefficient comparing unit and the combined coefficient are set. And the filter processing execution control unit in the filter processing unit that performs the filter processing between the fields of the graphics image data is controlled by the control signal using the comparison result as a control signal. Since the value can be set from the control unit, the filter control can be adaptively performed according to the type of the graphics image and the synthesis status. Therefore, only when the line flicker of the graphics image is conspicuous, the filtering process is performed, and the adaptive line flicker removal can be finely controlled in accordance with the type of the image and the synthesis state.

Further, according to the present invention, a threshold upper limit setting section which can set an arbitrary value from the control section is provided in the setting register section, and the threshold setting section and the threshold value setting section are provided in the coefficient comparing section. Filter processing execution control in the filter processing unit that compares the two thresholds set in the upper limit setting unit with the synthesis coefficient, and uses the comparison result as a control signal to perform a filter process between fields of the graphics image data. Since the control section controls the control section according to the control signal, an arbitrary threshold value can be set in the threshold upper limit setting section from the control section. Is extremely large, that is, a case where almost only a graphics image is displayed on the display, and in that case, the graphics are forcibly forced. It is possible not to perform the filtering hex image data. Therefore, claim 2
In addition to the effect of the present invention, when it is desired to give priority to the image quality of the graphics image even when line flicker is conspicuous such that almost only the graphics image is displayed on the display, the image is displayed without lowering the image quality of the graphics image Can be done.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an image synthesis processing device according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating a more detailed configuration of the image synthesis processing device of FIG. 1;

FIG. 3 is a conceptual diagram when a memory control processing unit reads two systems of data between fields from graphics image data stored in an image memory unit.

FIG. 4 is a block diagram illustrating a configuration of an image synthesis processing device according to a second embodiment of the present invention.

FIG. 5 is a block diagram illustrating a configuration of an image synthesis processing device according to a third embodiment of the present invention.

FIG. 6 is a block diagram illustrating a configuration of a conventional image synthesis processing device.

[Explanation of symbols]

1, 11, 21, 91 image synthesis processing device, 2 graphic image data generation unit, 3 filter processing unit,
4 control section, 5, 15, 25, 95 setting register section, 6, 16, 26 coefficient comparison section, 7 threshold value storage section, 8 image synthesis section, 9 image data input section,
10 image data output unit, 31 filter unit, 3
2, 33 filter processing execution control unit, 35 matrix processing unit, 36 LPF / subsampling unit, 41
Image memory unit, 42 Memory control processing unit, 43
Memory section, 44 synchronization signal input section, 45 timing signal generation section, 46 multiplexer section, 47 color information table storage section, 48 demultiplexer section, 5
1 Combination coefficient setting unit, 52 Threshold value setting unit, 53
Threshold upper limit setting unit, 54 filter execution setting unit,
61 first FIFO section, 62 second FIFO section.

Claims (3)

[Claims] A graphic image data generating section for generating video data of a graphic image; a filter processing section for performing a filter process between fields on video data of two vertical lines of the graphic image and outputting the video data; An image synthesizing unit for synthesizing the graphic image data output from the filter processing unit and the video image data input from the outside in accordance with the set synthesis coefficient; and a setting for executing the filter processing and a setting of the graphic image data and the image data. A setting register unit that stores the setting of the synthesis coefficient; and a control unit that controls the setting and control of each unit. The filtering unit controls the filtering process based on at least the setting for executing the filtering process. An image synthesis processing device having a filter processing execution control unit, wherein: A coefficient comparison unit configured to compare the set synthesis coefficient with a predetermined threshold value and output a comparison result, wherein the filter processing execution control unit is configured to execute the filter processing, An image synthesizing processing apparatus for performing a control for executing a filtering process on the graphic image data based on an output of the image synthesizing device. 2. The image synthesis processing device according to claim 1, wherein the setting register unit includes a threshold value setting unit that sets the threshold value according to an instruction from the control unit. 3. The setting register section includes a threshold upper limit setting section that sets an upper limit value of the threshold value according to an instruction from the control section, and the coefficient comparing section includes the threshold value and the threshold value. A comparison result of comparing with a threshold value set in the value setting section, and
The image synthesis processing apparatus according to claim 2, wherein both of the comparison result obtained by comparing the synthesis coefficient and a threshold value set in the threshold upper limit setting unit are output to the filter processing execution control unit. .