JP2021190824A - Color irregularity adjustment system, video display device and color irregularity adjustment method - Google Patents

Abstract

To provide a color irregularity adjustment system which does not need to perform calibration of an imaging device, allows even an inexperienced user to easily adjust color irregularity and improves a convergence property of correction data of a pixel value of a display image from a photographed image captured by an inexpensive camera.SOLUTION: A color irregularity adjustment system comprises: a chromaticity distribution detection unit which obtains chromaticity of each pixel of a photographed image of a display screen; a chromaticity ratio calculation unit which obtains a chromaticity ratio being a ratio of a center pixel to the chromaticity of another pixel for each pixel with the chromaticity of the center pixel of the photographed image as reference chromaticity; a chromaticity difference calculation unit which obtains a chromaticity difference between the reference chromaticity and the chromaticity of the other pixel for each pixel; a correction gain generation unit which obtains a correction gain for correcting the pixel value of each pixel of the display image with the chromaticity ratio and a reference chromaticity ratio being the chromaticity ratio used in immediately-previous processing; a correction data generation unit which calculates correction data of each pixel by multiplying each correction gain by the color difference of each pixel; and a pixel value correction unit which corrects the pixel value of each pixel of the display image with the correction data.SELECTED DRAWING: Figure 1

Description

The present invention relates to a color unevenness adjustment system, an image display device, and a color unevenness adjustment method.

In an image display device, color unevenness occurs between pixels in a displayed image due to a difference in brightness or color.
For example, in a projection type liquid crystal display device, the brightness and color of each pixel in the image may differ due to the variation in the transmittance between the pixels in the liquid crystal panel, and in the direct view type display device, due to the uneven irradiation of the backlight. Color unevenness occurs between them.
In particular, as the image to be displayed becomes larger, color unevenness becomes remarkable between each place in the image, and it is necessary to adjust the brightness or color for each pixel of the image in order to improve the appearance of the image.

This color unevenness correction is performed by capturing a display image displayed by the image display device using an image pickup device such as a camera and detecting the distribution of white balance in the display image from the captured image data.
Then, based on the white balance distribution in the displayed image, correction data for performing brightness adjustment or color adjustment between pixels is generated, and the pixel data of the display image in the image display device is corrected (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 06-217336

However, depending on the gain characteristic (sensitivity characteristic) of the image pickup apparatus, the color unevenness in the displayed image actually displayed and the color unevenness in the captured image captured by the image pickup apparatus are different.
Therefore, since the white balance and color gain of the captured image are different from those of the actual displayed image, it is difficult to obtain correction data capable of sufficiently correcting the color unevenness of the displayed image.

Further, the output characteristics of the pixel data in the image display device and the image output corresponding to the pixel data do not have linearity.
Therefore, it is difficult for the correction of the pixel data by the acquired correction data to be reflected in the image output due to each of the gain characteristic of the image pickup apparatus and the output characteristic of the image display apparatus.
In order to solve the above-mentioned problem, it is necessary to repeatedly perform the process of capturing the display image after adjusting the pixel data and adjusting and acquiring the correction data for correcting the color unevenness of the display image.

However, in the case of Patent Document 1, when the gain characteristic is smaller than a predetermined value, the chromaticity difference indicating color unevenness cannot be sufficiently detected from the captured image, and fine adjustment is repeated, and correction data is acquired. It takes a long time to converge.
On the other hand, when the gain characteristic is larger than a predetermined value, the chromaticity difference indicating color unevenness is detected from the captured image to be larger than the actual value, and the rough adjustment is repeated, and the value of the correction data diverges without converging. Resulting in.

Therefore, when used for adjusting color unevenness, it is conceivable to strictly control the camera characteristics of the image pickup apparatus or to detect the camera characteristics in advance and acquire calibration data.
However, it is difficult for users who have little experience in adjusting the color unevenness of the display screen using an image pickup device to strictly manage the camera characteristics, and it is not easy to acquire calibration data and perform calibration. ..
Further, when an expensive image pickup device having high accuracy cannot be used and a digital camera having low accuracy is used, it is difficult for a user who has experience in adjusting color unevenness to strictly control the camera characteristics. ..

The present invention has been made in view of such circumstances, and it is not necessary to calibrate the image pickup device, it is easy for an inexperienced user to adjust the color unevenness, and the captured image captured by an inexpensive camera is used. To provide a color unevenness adjustment system, a video display device, and a color unevenness adjustment method for improving the convergence of correction data of pixel values of a display image.

In order to solve the above-mentioned problems, the color unevenness adjustment system of the present invention has a chromaticity distribution detection unit that obtains the chromaticity of each pixel in the captured image obtained by capturing the display image displayed on the display screen, and the captured image. The chromaticity ratio calculation unit for obtaining the chromaticity ratio, which is the ratio between the central pixel and the chromaticity of other pixels, with the chromaticity of the central pixel, which is the central pixel, as the reference chromaticity, and the reference. The chromaticity difference calculation unit for obtaining the color difference between the chromaticity and the chromaticity of the other pixels for each pixel, the chromaticity ratio, and the chromaticity obtained by the chromaticity difference calculation unit in the immediately preceding calculation process. A correction gain generator for obtaining a correction gain for correcting each pixel value of a pixel in the display image by a reference chromaticity ratio, which is a ratio, and a correction gain generation unit for multiplying the color difference of each of the pixels by the correction gain. It is characterized by including a correction data generation unit that calculates the correction data of each of the pixels, and a pixel value correction unit that corrects the pixel value of each of the display images displayed on the display screen by the correction data. And.

The image display device of the present invention includes the color unevenness adjustment system, a display panel, and a display control unit that displays the pixel value output by the adjustment device on the display panel.

In the color unevenness adjusting method of the present invention, the chromaticity distribution detection unit obtains the chromaticity of each pixel in the captured image obtained by capturing the display image displayed on the display screen, and the chromaticity ratio calculation unit. However, the chromaticity ratio is calculated for each pixel, which is the ratio of the central pixel to the chromaticity of other pixels, using the chromaticity of the central pixel, which is the central pixel of the captured image, as the reference chromaticity. The process and
The chromaticity difference calculation unit obtains the chromaticity difference between the reference chromaticity and the chromaticity of the other pixels for each pixel, and the correction gain generation unit determines the chromaticity ratio and the chromaticity. A correction gain generation process for obtaining a correction gain for correcting each pixel value of a pixel in the display image based on a reference chromaticity ratio, which is a chromaticity ratio obtained by the difference calculation unit in the immediately preceding calculation process, and correction data. A correction data generation process in which the generation unit calculates the correction data for each of the pixels by multiplying the color difference of each of the pixels by the correction gain, and the pixel value correction unit uses the correction data to display the display screen. It is characterized by including a pixel value correction process for correcting the pixel value of each of the displayed images to be displayed in.

As described above, according to the present invention, it is not necessary to calibrate the image pickup device, it is easy for an inexperienced user to adjust the color unevenness, and the display image is obtained from the captured image captured by an inexpensive camera. It is possible to provide a color unevenness adjustment system, an image display device, and a color unevenness adjustment method for improving the convergence of pixel value correction data.

It is a block diagram which shows the structural example of the image display apparatus which used the color unevenness adjustment system by one Embodiment of this invention. It is a conceptual diagram which shows an example of the chromaticity ratio used to obtain the correction gain. It is a flowchart which shows the operation example of the generation process of the correction data which performs the color unevenness correction by the color unevenness adjustment system 100 by one Embodiment of this invention. It is a conceptual diagram which shows the operation example of the generation processing of the correction data which performs the color unevenness correction by the color unevenness adjustment system 100 by one Embodiment of this invention. It is a figure explaining the concept of the color unevenness adjustment system by embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a configuration example of an image display device using the color unevenness adjustment system according to the embodiment of the present invention. In FIG. 1, the image display device 1 according to the present embodiment includes each of a color unevenness adjustment system 100, a display control unit 200, and a display panel 300. In the present embodiment, the image display device 1 is, for example, a three-panel projection type liquid crystal display device.

The color unevenness adjustment system 100 corrects the pixel value of the video signal supplied from the external device in order to adjust the color unevenness due to the difference in the display characteristics of the pixels on the display screen of the display panel 300.
The display control unit 200 sequentially supplies the pixel values of the video signal corrected by the color unevenness adjustment system 100 to the display panel 300 as pixel values of the display image to be displayed on the screen 2 frame by frame.
The display panel 300 displays the pixel value of the video signal supplied from the display control unit 200 on the corresponding pixel in the liquid crystal panel (liquid crystal light valve), irradiates the liquid crystal panel with the projected light, and transmits the light through the liquid crystal panel. The projected light is projected onto the screen 2 to display the displayed image on the screen 2.

The screen 2 is a reflective front type screen used in, for example, a home theater.
The image pickup device 3 is, for example, a digital camera, and is used for capturing a display image displayed on the screen 2 and acquiring captured image data. This captured image data is supplied to the color unevenness adjustment system 100.

The color unevenness adjustment system 100 includes an image capture image input unit 101, a chromaticity distribution detection unit 102, a chromaticity ratio calculation unit 103, a chromaticity difference calculation unit 104, a correction gain generation unit 105, a correction data generation unit 106, and a pixel value correction unit. Each of 107, a color unevenness determination unit 108, a captured image storage unit 109, and a correction data table 110 is provided.
The captured image input unit 101 inputs the data (bitmap table) of the captured image captured by the imaging device 3 via a USB cable or the like, and extracts only the image area of the screen 2 from the captured image by processing such as contour extraction. (Cut out).
Then, the captured image input unit 101 writes and stores the data of the extracted target captured image in the captured image storage unit 109.

The chromaticity distribution detection unit 102 standardizes the pixel value of each pixel of the target captured image (for example, consisting of the pixel values of the color components R, G, and B) based on the brightness value obtained from each pixel value. By doing so, the chromaticity (for example, the coordinate value in the xy chromaticity diagram) is obtained, and a chromaticity distribution map showing the obtained chromaticity at the position of each pixel is generated.
Then, the chromaticity distribution detection unit 102 writes the generated chromaticity distribution map in the captured image storage unit 109 and stores it.

The chromaticity ratio calculation unit 103 uses the chromaticity of the representative pixel in the pixel of the target captured image as the reference chromaticity, divides the chromaticity of each pixel in the chromaticity distribution map, and determines the chromaticity of each pixel with respect to the reference chromaticity. The chromaticity ratio is calculated, and a chromaticity ratio distribution map showing the obtained chromaticity ratio at the position of each pixel is generated.
Then, the chromaticity ratio calculation unit 103 writes and stores the generated chromaticity ratio distribution map in the captured image storage unit 109.

At this time, the chromaticity ratio calculation unit 103 uses the chromaticity ratio distribution map generated from the previous target captured image as a reference chromaticity ratio distribution map, and the chromaticity ratio distribution generated from the newly input target captured image. An identifier that simply uses the map as a color ratio distribution map is assigned, and processing is performed to manage them separately.
Here, any pixel of the target captured image may be used as the representative pixel, but in the present embodiment, for example, the pixel in the center of the pixel in the target captured image is used.

The chromaticity difference calculation unit 104 uses the chromaticity of the representative pixel in the pixel of the target captured image as the reference chromaticity, subtracts the chromaticity of each pixel in the chromaticity distribution map, and determines the chromaticity of each pixel with respect to the reference chromaticity. The chromaticity difference is calculated, and a chromaticity difference distribution map showing the obtained chromaticity difference at the position of each pixel is generated.
Then, the chromaticity difference calculation unit 104 writes and stores the generated chromaticity difference distribution map in the captured image storage unit 109.

The correction gain generation unit 105 refers to each of the chromaticity ratio distribution map and the reference chromaticity ratio distribution map in the captured image storage unit 109, and subtracts the reference chromaticity ratio from the target chromaticity ratio of the representative pixel to obtain the color. The correction gain for each pixel is obtained by dividing by the result of subtracting the reference brightness ratio from the degree ratio. Here, the target chromaticity ratio is basically "1" because it is a numerical value obtained by dividing the chromaticity of the representative pixel by the chromaticity ratio of the representative pixel. The reference chromaticity ratio indicates the chromaticity ratio of each pixel in the reference chromaticity ratio distribution map. The chromaticity ratio indicates the chromaticity ratio of each pixel in the chromaticity ratio distribution map.

That is, the correction gain generation unit 105 uses each of the chromaticity ratio and the reference chromaticity ratio of each pixel in the target captured image and the target chromaticity ratio of the representative pixel to obtain the correction gain of each pixel in the captured image. Make a calculation.
Then, the correction gain generation unit 105 generates a correction gain distribution map in which each of the correction gains obtained at the positions of each pixel is shown.
Then, the correction gain generation unit 105 writes and stores the generated correction gain distribution map in the captured image storage unit 109.

FIG. 2 is a conceptual diagram showing an example of the chromaticity ratio used to obtain the correction gain.
FIG. 2A shows the chromaticity ratio in the chromaticity ratio distribution map obtained from the captured image input immediately before the newly input captured image, that is, the chromaticity generated from the previously input captured image. An example of the reference chromaticity ratio in the reference chromaticity ratio distribution map, which is a ratio distribution map, is shown.
FIG. 2B shows an example of the chromaticity ratio in the chromaticity ratio distribution map obtained from the newly input captured image.

Each of FIGS. 2 (a) and 2 (b) shows the chromaticity ratio of each of the color component R, the color component G, and the color component B in the same pixel.
In the present embodiment, the chromaticity ratio is obtained by obtaining the color component R, the color component G, and the color component B obtained from the chromaticity of each pixel of the chromaticity distribution map from the chromaticity of the representative pixel in this chromaticity distribution map. The ratio of the pixel value obtained from each color component of the pixel to the pixel value obtained from the chromaticity of the representative pixel by dividing each of the color component R, the color component G, and the color component B is shown.

In FIG. 2A, the target chromaticity ratio of the color component R (Red) is “1.0”, the reference chromaticity ratio is “0.7”, and the target color of the color component G (Green). The degree ratio is "1.0", the reference chromaticity ratio is "0.7", the target chromaticity ratio of the color component B (Blue) is "1.0", and the reference chromaticity ratio is "". 1.2 ".
On the other hand, in FIG. 2B, the target chromaticity ratio of the color component R is "1.0", the chromaticity ratio is "1.1", and the target chromaticity ratio of the color component G is "1". It is "0.0", the chromaticity ratio is "0.9", the target chromaticity ratio of the color component B is "1.0", and the chromaticity ratio is "0.8".

Therefore, the correction gain generation unit 105 sets the target chromaticity ratio, the reference chromaticity ratio, and the chromaticity ratio of each of the color component R, the color component G, and the color component B of the pixel for which the correction gain is generated to (. Substitute in the formula of target chromaticity ratio-reference chromaticity ratio) / (chromaticity ratio-reference chromaticity ratio).
Then, the correction gain generation unit 105 is used to generate a correction data adjustment value (described later) for adjusting the correction data of each pixel value of the color component R, the color component G, and the color component B in the pixel to be corrected. The correction gains for each of the component R, the color component G, and the color component B are generated.

In FIG. 2, the correction gain generation unit 105 has, for example, (1.0-0.7) / (1.1-0.7) = 0.3 / 0.4 = 0 as the correction gain of the color component R. Calculate .75. Further, the correction gain generation unit 105 calculates (1.0-0.7) /(0.9-0.7)=0.3/0.2=1.5 as the correction gain of the color component G. do. Similarly, the correction gain generation unit 105 sets the correction gain of the color component B as (1.0-1.2) /(0.8-1.2)=-0.2/-0.4=0. 5 is calculated. Here, the correction gain generation unit 105 calculates the correction gain as an absolute value.

Returning to FIG. 1, the correction data generation unit 106 refers to the chromaticity difference distribution map in the captured image storage unit 109, and each of the color component R, the color component B, and the color component B obtained from the chromaticity difference of each pixel. Find the pixel value difference.
Then, the correction data generation unit 106 reads out each of the color component R, the color component G, and the color component B of each pixel with reference to the correction gain distribution map, and the color component R, the color component G, and the color of the corresponding pixel. The correction data adjustment value for adjusting the correction data for correcting the pixel value for each of the color component R, the color component G, and the color component B is calculated by multiplying the component B.

Further, the correction data generation unit 106 adds the obtained correction data adjustment value to the correction data at the position corresponding to the obtained pixel in the correction data table 110 to obtain new correction data. In the correction data table, for each of the color component R, the color component G, and the color component B, each pixel value (for example, gradation degree) or a plurality of predetermined different pixel values (for example, gradation degree 0, gradation degree 20) are obtained. , 40, ..., 240, 256, etc.).

When the correction data is set for each of the plurality of gradations, the gradations for which the correction data is not set are complemented by the correction data sandwiching the unset gradations (straight line complementation, etc.). )calculate. When the color unevenness adjustment system is initialized, the numerical values of the correction data in all the correction data tables are reset to the same pixel values as the respective pixel values.
Therefore, in order to generate a correction data table for a plurality of pixel values, for example, the above-mentioned correction data adjustment value is calculated using a plurality of gray cards having different pixel values.

The pixel value correction unit 107 refers to the correction data table 110 corresponding to each pixel value of the color component R, the color component G, and the color component B of the pixel in each frame of the video signal supplied from the outside, and corrects each of them. Read the data.
Then, the pixel value correction unit 107 sets the pixel value of the read correction data as the pixel value of each of the color component R, the color component G, and the color component B of the pixel in the frame of the video signal, so that the frame of the video signal has a pixel value. Correct the pixel value of the pixel.
The pixel value correction unit 107 outputs the frame data of the corrected video signal to the display control unit 200.

As a result, the display control unit 200 sequentially supplies the pixel values of the video signal corrected by the color unevenness adjustment system 100 to the display panel 300 as pixel values of the display image to be displayed on the screen 2 frame by frame.
The display panel 300 controls the aperture ratio of the light valve of the liquid crystal panel by the pixel value of the video signal supplied from the display control unit 200, irradiates the liquid crystal panel with the projected light, and transmits the projected light through the liquid crystal panel. Is projected onto the screen 2 to display the displayed image on the screen 2.

Each time the correction data table 110 is rewritten, the color unevenness determination unit 108 refers to the chromaticity difference distribution map in the captured image storage unit 109, and extracts, for example, the maximum chromaticity difference as a color unevenness determination value.
Then, the color unevenness determination unit 108 determines whether or not the extracted color unevenness determination value exceeds a preset threshold value. When the color unevenness determination value is equal to or less than a preset threshold value, the color unevenness determination unit 108 terminates the color unevenness adjustment process, assuming that the color unevenness can be suppressed within a predetermined chromaticity difference range.
On the other hand, when the color unevenness determination value exceeds a preset threshold value, the color unevenness determination unit 108 continues the color unevenness adjustment process, assuming that the color unevenness cannot be suppressed within a predetermined chromaticity difference range.

Next, the process of generating the correction data table 110 for correcting the pixel value of the video signal by the color unevenness adjustment system 100 according to the present embodiment will be described with reference to FIGS. 3 and 4.
FIG. 3 is a flowchart showing an operation example of a correction data generation process for performing color unevenness correction by the color unevenness adjusting system 100 according to the embodiment of the present invention. FIG. 4 is a conceptual diagram showing an operation example of a correction data generation process for performing color unevenness correction by the color unevenness adjusting system 100 according to the embodiment of the present invention.

Step S1: As a video signal, image data for adjustment in which each pixel of the frame for color unevenness adjustment has the same pixel value is supplied to the color unevenness adjustment system 100.
At this time, the correction data corresponding to the pixel value of each pixel in the correction data table 110 is set to have the same pixel value as the pixel value.
Then, the pixel value correction unit 107 extracts correction data by referring to the correction data table 110 for the pixel values of the color component R, the color component G, and the color component B in the pixels of the frame (color unevenness in FIG. 4). Corresponds to the correction process 201).

At this point, each of the pixel values of the pixels in the frame is supplied to the display panel 300 via the display control unit 200 as an uncorrected numerical value at the time of input. As a result, the display panel 300 projects a display image corresponding to the pixel value of the pixel of the supplied frame to the screen 2 (corresponding to the display image processing 202 of FIG. 4).
The user captures the display image displayed on the screen 2 by the image pickup device 3 (corresponding to the image pickup process 203 of FIG. 4), and inputs the captured image to the color unevenness adjustment system 100 (the captured image of FIG. 4). Corresponds to data capture 204).
Then, the captured image input unit 101 extracts the target captured image from the captured image, writes it to the captured image storage unit 109, and stores it.

Step S2: The chromaticity distribution detection unit 102 reads the target captured image from the captured image storage unit 109, and standardizes the pixel value of each pixel of the target captured image by the brightness value obtained from each pixel value. The chromaticity is obtained, and a chromaticity distribution map showing the obtained chromaticity at the position of each pixel is generated (corresponding to the chromaticity distribution detection 205 in FIG. 4).
Then, the chromaticity distribution detection unit 102 writes and stores the generated chromaticity distribution map in the captured image storage unit 109.
The chromaticity ratio calculation unit 103 refers to the chromaticity distribution map of the captured image storage unit 109 to generate a chromaticity ratio distribution map showing the chromaticity ratio of each pixel in the target captured image (FIG. 4). Corresponds to the chromaticity ratio calculation 206), and writes and stores it in the captured image storage unit 109.

Step S3: The correction gain generation unit 105 refers to the reference chromaticity ratio map and the chromaticity ratio map in the captured image storage unit 109, and the correction gain of each of the color component R, the color component G, and the color component B of the pixel. Is calculated (corresponding to the correction gain generation 207 in FIG. 4), and is written and stored in the captured image storage unit 109 as a correction gain distribution map.

Step S4: The chromaticity difference calculation unit 104 refers to the chromaticity ratio distribution map of the captured image storage unit 109 to obtain the chromaticity difference, which is the difference in chromaticity between the representative pixel and each pixel (color in FIG. 4). Corresponds to degree difference generation 208).
Then, the chromaticity difference calculation unit 104 writes and stores the chromaticity difference of each pixel in the frame as a chromaticity difference distribution map in the captured image storage unit 109.
The correction data generation unit 106 refers to the correction gain distribution map and the chromaticity difference distribution map of the captured image storage unit 109, and multiplies the correction gain by the pixel value difference obtained from the chromaticity difference of each of the corresponding pixels. The correction data adjustment value is calculated (corresponding to the multiplication process 209 in FIG. 4).
Further, the correction data generation unit 106 adds the calculated correction data adjustment value to the correction data in the correction data table 110 (corresponding to the addition process 210 in FIG. 4), and changes the correction data (FIG. 4). Corresponds to the correction data change 211).

Step S5: As a video signal, image data for adjustment in which each pixel of the frame for color unevenness adjustment has the same pixel value is supplied to the color unevenness adjustment system 100.
Then, the pixel value correction unit 107 corrects the pixel values of the color component R, the color component G, and the color component B in the pixels of the frame by the correction data extracted with reference to the correction data table 110 corresponding to the pixel values. (Corresponding to the color unevenness correction process 201 in FIG. 4).
As a result, the display panel 300 projects a display image corresponding to the pixel value of the pixel of the supplied frame to the screen 2 (corresponding to the display image processing 202 of FIG. 4).
The user captures the display image displayed on the screen 2 by the image pickup device 3 (corresponding to the image pickup process 203 of FIG. 4), and inputs the captured image to the color unevenness adjustment system 100 (the captured image of FIG. 4). Corresponds to data capture 204).
Then, the captured image input unit 101 extracts the target captured image from the captured image, writes it to the captured image storage unit 109, and stores it.

Step S6: The chromaticity distribution detection unit 102 reads the target captured image from the captured image storage unit 109, and standardizes the pixel value of each pixel of the target captured image by the brightness value obtained from each pixel value. The chromaticity is obtained, and a chromaticity distribution map showing the obtained chromaticity at the position of each pixel is generated (corresponding to the chromaticity distribution detection 205 in FIG. 4).
Then, the chromaticity ratio calculation unit 103 refers to the chromaticity distribution map of the captured image storage unit 109 to generate a chromaticity ratio distribution map showing the chromaticity ratio of each pixel in the target captured image (Fig.). (Corresponding to the chromaticity ratio calculation 206 of 4), it is written and stored in the captured image storage unit 109.
At this time, the chromaticity ratio calculation unit 103 uses the chromaticity ratio distribution map generated from the previous target captured image as a reference chromaticity ratio distribution map, and the chromaticity ratio distribution generated from the newly input target captured image. An identifier that simply uses the map as a color ratio distribution map is assigned, and processing is performed to manage them separately.

Step S7: Each time the correction data table 110 is rewritten, the color unevenness determination unit 108 refers to the chromaticity difference distribution map in the captured image storage unit 109 and extracts the maximum chromaticity difference.
Then, the color unevenness determination unit 108 determines whether or not the extracted color unevenness determination value exceeds a preset threshold value.
At this time, when the color unevenness determination value is equal to or less than a preset threshold value, the color unevenness determination unit 108 ends the color unevenness adjustment process, assuming that the color unevenness can be suppressed within a predetermined chromaticity difference range.
On the other hand, when the color unevenness determination value exceeds a preset threshold value, the color unevenness determination unit 108 considers that the color unevenness cannot be suppressed within a predetermined chromaticity difference range and continues the color unevenness adjustment process. To step S3.

As described above, according to the present embodiment, the correction data adjustment value for changing the correction data is reflected in the display image to what extent the pixel value of the corrected video signal is reflected, that is, imaging. The effects of each of the gain characteristics of the device and the output characteristics of the image display device are quantified, obtained as the correction gain, and the correction data adjustment value based on the chromaticity difference between the standard pixel and other pixels in the captured image is calculated. By adding the correction data adjustment value and the correction data (accumulating the correction data adjustment value) and changing the correction data, the number of processes for setting the color unevenness judgment value to the threshold value or less is reduced compared to the conventional method. Therefore, the correction data can be easily converged, and even a user who has little experience in adjusting the color unevenness of the display screen using the image pickup device can calibrate the image pickup device. It is not necessary, and it is possible to easily adjust the color unevenness using the captured image captured by an inexpensive camera.

In the present embodiment, an example in which the color unevenness adjustment system 100 is applied to a three-panel projection type liquid crystal display device has been described, but the same applies to a direct-view type image display device (for example, a liquid crystal monitor) using a liquid crystal display. Can be used for.

FIG. 5 is a diagram illustrating a concept of a color unevenness adjustment system according to an embodiment of the present invention.
In FIG. 5, the chromaticity distribution detection unit 102 obtains the chromaticity of each pixel in the captured image obtained by capturing the display image displayed on the display screen.
The chromaticity ratio calculation unit 103 uses the chromaticity of the central pixel, which is the central pixel of the captured image, as a reference chromaticity, and sets the chromaticity ratio, which is the ratio between the central pixel and the chromaticity of other pixels, for each pixel. Ask for.
The chromaticity difference calculation unit 104 obtains the color difference between the reference chromaticity and the chromaticity of other pixels in the captured image for each pixel.
The correction gain generation unit 105 corrects the pixel value of each pixel in the display image by the chromaticity ratio and the reference chromaticity ratio, which is the chromaticity ratio obtained by the chromaticity difference calculation unit in the immediately preceding calculation process. Find the correction gain for.
The correction data generation unit 106 calculates the correction data for each pixel by multiplying the color difference for each pixel by each correction gain.
The pixel value correction unit 107 corrects each pixel value of the display image displayed on the display screen by the correction data.

It should be noted that the correction gain is acquired from the color difference of the pixel values between the pixels of the captured image captured on the display screen in the color unevenness adjustment system 100 of FIG. 1 of the present invention, and the pixel values of the pixels in the display image are corrected. By recording a program for realizing the function of adjusting the correction data for the computer on a computer-readable recording medium, and having the computer system read and execute the program recorded on the recording medium, in the reflection region. You may control the adjustment process of the amount of reflected blue light. The term "computer system" as used herein includes hardware such as an OS and peripheral devices.

Further, the "computer system" shall also include a WWW system provided with a homepage providing environment (or display environment). Further, the "computer-readable recording medium" refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, or a CD-ROM, and a storage device such as a hard disk built in a computer system. Furthermore, a "computer-readable recording medium" is a volatile memory (RAM) inside a computer system that serves as a server or client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, it shall include those that hold the program for a certain period of time.

Further, the program may be transmitted from a computer system in which this program is stored in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the "transmission medium" for transmitting a program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. Further, the above program may be for realizing a part of the above-mentioned functions. Further, a so-called difference file (difference program) may be used, which can realize the above-mentioned function in combination with a program already recorded in the computer system.

1 ... Image display device 2 ... Screen 3 ... Image pickup device 100 ... Color unevenness adjustment system 101 ... Captured image input section 102 ... Chromaticity distribution detection section 103 ... Chromaticity ratio calculation section 104 ... Chromaticity difference calculation section 105 ... Correction gain generation Unit 106 ... Correction data generation unit 107 ... Pixel value correction unit 108 ... Color unevenness determination unit 109 ... Captured image storage unit 110 ... Correction data table 200 ... Display control unit 300 ... Display panel

Claims (6)

A chromaticity distribution detection unit that obtains the chromaticity of each pixel in the captured image obtained by capturing the display image displayed on the display screen, and
With the chromaticity ratio calculation unit that obtains the chromaticity ratio, which is the ratio between the central pixel and the chromaticity of other pixels, using the chromaticity of the central pixel, which is the central pixel of the captured image, as the reference chromaticity. ,
A chromaticity difference calculation unit that obtains the color difference between the reference chromaticity and the chromaticity of the other pixels for each pixel.
The correction gain for correcting the pixel value of each pixel in the display image by the chromaticity ratio and the reference chromaticity ratio, which is the chromaticity ratio obtained by the chromaticity difference calculation unit in the immediately preceding calculation process, is obtained. The desired correction gain generator and
A correction data generation unit that calculates correction data for each pixel by multiplying the color difference of each of the pixels by each of the correction gains.
A color unevenness adjusting system including a pixel value correction unit that corrects the pixel value of each of the displayed images displayed on the display screen by the correction data. The correction gain generation unit divides the difference between the target value, which is the ratio between the reference chromaticity and the reference chromaticity, and the reference chromaticity ratio by the difference between the chromaticity ratio and the reference chromaticity ratio. The color unevenness adjustment system according to claim 1, wherein the result of the division is used as the correction gain. The correction data generation unit multiplies the color difference by the correction gain to generate correction data, adds the correction data to the correction data obtained in the previous process, and newly corrects the addition result. The color unevenness adjustment system according to claim 2, wherein the data is used. The pixel value correction unit includes a look-up table showing the correspondence between the input input pixel value and the correction pixel value of the input pixel value in each of the display pixels which are the pixels of the display screen.
The correction data generation unit adds the correction data to each of the input pixel values in the lookup table, obtains each of the correction pixel values corresponding to the input pixel value, and writes the correction data to the lookup table.
The pixel value correction unit is characterized in that the pixel value of the display pixel is used as the input pixel value and the correction pixel value obtained from the lookup table is used as the pixel value of the display pixel to be displayed on the display screen. The color unevenness adjustment system according to any one of claims 1 to 3. The color unevenness adjustment system according to any one of claims 1 to 4.
Display panel and
A video display device including a display control unit that displays the pixel value output by the adjustment system on the display panel. The chromaticity distribution calculation process in which the chromaticity distribution detection unit obtains the chromaticity of each pixel in the captured image obtained by capturing the display image displayed on the display screen, and
The chromaticity ratio calculation unit uses the chromaticity of the central pixel, which is the central pixel of the captured image, as the reference chromaticity, and determines the chromaticity ratio, which is the ratio between the central pixel and the chromaticity of other pixels, for each pixel. The desired chromaticity ratio calculation process and
A color difference calculation process in which the chromaticity difference calculation unit obtains the chromaticity between the reference chromaticity and the chromaticity of the other pixels for each pixel.
The correction gain generation unit corrects the pixel value of each pixel in the display image by the chromaticity ratio and the reference chromaticity ratio which is the chromaticity ratio obtained by the chromaticity difference calculation unit in the immediately preceding calculation process. The correction gain generation process to obtain the correction gain for
A correction data generation process in which the correction data generation unit calculates the correction data for each of the pixels by multiplying the color difference of each of the pixels by the correction gain.
A color unevenness adjusting method comprising a pixel value correction process in which a pixel value correction unit corrects the pixel value of each of the display images displayed on the display screen by the correction data.

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