JP2002055668A - Display device input / output characteristic measurement method, display device image correction method, display device ICC profile creation method, storage medium storing procedures of those methods, and display device - Google Patents

Abstract

(57) [Problem] To perform input / output by performing appropriate calibration without using expensive measurement equipment even in a display device such as a liquid crystal display device that cannot express input / output characteristics only with a gamma value or gamma characteristic. The characteristics are obtained, and an ICC profile is created based on the characteristics. SOLUTION: White and black color patches PatA, Pat
B is compared with the background pattern in which B is arranged at the same ratio and the single-color patch PatC.
Adjust the R, G, and B values of tC, and adjust the gray R between white and black.
Measure the GB value. Next, PatC is compared with a background pattern in which white or black and the measured gray are arranged at the same ratio as PatA and PatB, and the R, G, and B values of PatC are adjusted so that both appear to match. Measure the RGB values of gray between white or black and gray. In this manner, the calibration is repeated to obtain input / output characteristic data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device which enables a user to measure input / output characteristics without using dedicated measuring equipment, a method for measuring the input / output characteristics, and a method for measuring the input / output characteristics based on the measured data. You can simulate what your image will look like, correct the image in real time, see the difference between the original and the corrected image,
An image correction method for a display device capable of making fine adjustments so as to optimize the appearance of the image, an ICC profile creation method for creating an ICC profile from measured data, and storage of those procedures. Regarding the medium.

[0002]

2. Description of the Related Art In a display device such as a liquid crystal display device or a CRT, the appearance of colors differs for each display method due to differences in contrast, saturation limit (color gamut), luminance characteristics and the like.
In addition, lighting conditions in the environment where the display device is installed,
The way the color looks and feels changes depending on the angle and distance when viewing the display device. Further, since the device characteristics change due to aging, even if the characteristics at the time of shipment are the same, the characteristics change depending on how the device is used thereafter.

Further, when exchanging data with peripheral devices such as printers and scanners, it is natural that input / output characteristics and color gamut are different, so that the appearance of an image is the same even if the device is different. To do so, it is necessary to calibrate the characteristics and create a profile describing the characteristics for each device.

[0004] Color management system (CMS)
In order to reduce such a difference in appearance between devices, appropriate color conversion is performed based on a profile for each device. However, in order to create a profile suitable for each device, for example, if it is a display device,
Measuring equipment such as a spectrophotometer is required. However, since high-precision measuring instruments are expensive, it is difficult for the user to perform independent measurement.

It is also conceivable that the manufacturer prepares a profile at the time of shipment. However, if there is a large change in display characteristics due to the lighting conditions and aging of the user, it is assumed that the manufacturer prepares the profile at the time of shipment. However, there is a problem that the appearance of colors is shifted.

Therefore, Japanese Patent Application Laid-Open Nos. Hei 7-285241 and Hei 11-338443 disclose a method of measuring characteristics of a display device using only software without using a measuring device.

[0007]

However, the technique disclosed in Japanese Patent Application Laid-Open No. 7-285241 displays grayscale patches based on gamma curves corresponding to n gamma values with respect to luminance. It selects which gamma value is the most linear. For this reason,
It cannot be applied to a display device using liquid crystal or the like, which often cannot express input / output characteristics with a single gamma value.

The technique disclosed in Japanese Patent Application Laid-Open No. 11-338443 is also based on the premise that it has a gamma characteristic. For example, in the case of 24-bit color display, gray between white and black is represented by RGB = (0, 0,0), (1,1,
1), (2, 2, 2), ..., (255, 255, 2)
55). Here, the values in parentheses are the luminance values of R (red), G (green), and B (blue), with the maximum value being 255 and the minimum value being 0. It represents the darkest.

However, in the case of a liquid crystal display device,
For example, since only blue appears strongly, color matching cannot always be performed by this method. Similarly, for the halftone between black (red, blue, green) and black,
If the intensities of R, G, and B are different, the color tone changes, so that it is difficult to perform accurate color matching. In particular, a liquid crystal display device often exhibits characteristics different from those of a CRT in terms of maximum chroma, luminance characteristics, chromaticity dependence on viewing angle, chromaticity characteristics on gradation, and the like.

That is, in a display device using an ordinary liquid crystal, since the characteristics change for each of the RGB colors in the halftone, the luminance characteristics cannot be approximated by a gamma curve. Lack of accuracy in point.

SUMMARY OF THE INVENTION The present invention has been made to solve such problems of the prior art, and is intended for a display device such as a liquid crystal display device which cannot express input / output characteristics only by a gamma value or a gamma characteristic. Also, it is possible to create an ICC profile based on measurement data by performing appropriate calibration without using expensive measurement equipment, a method of measuring input / output characteristics of a display device, a method of correcting an image of a display device, and an ICC of a display device. It is an object to provide a profile creation method, a storage medium storing a procedure of the method, and a display device.

[0012]

According to the method of measuring input / output characteristics of a display device of the present invention, a color patch of an arbitrary one color and a color patch of an arbitrary color different from the one are arranged at the same ratio and two colors are arranged. A first display area displayed so as to appear as an intermediate color of the first display area and a second display area displaying a single color patch, and measuring input / output characteristics of the display device. Black is displayed as one of the two colors and white is displayed as the other one, and the average of the luminance values of the three primary colors that make up black and the luminance values of the three primary colors that make up white The values are used as input-related measurement data, and the luminance values of the three primary colors that make up the single color of the second display area are adjusted so that the colors of the first display area and the colors of the second display area look closest. And configures a single color of the second display area at that time.
After performing the first step of obtaining the input / output characteristics using the respective luminance values of the primary colors as measurement data relating to the output, black or white is displayed as one of the two colors of the first display area, and the other color is displayed. Display the color set as the color of the second display area in the previous step, and input the respective luminance values of the three primary colors constituting black or white and the color set as the color of the second display area in the previous step The average value with the measurement data on the input is used as the measurement data on the input, and the average 3
By adjusting the luminance values of the primary colors, the colors of the first display area and the colors of the second display area are set so as to appear closest to each other, and the three primary colors constituting the single color of the second display area at that time are set. A second step of obtaining input / output characteristics using each luminance value as measurement data relating to output; and a color set as one of the two colors of the first display area as a color of the second display area in the previous step. Is displayed, and another color set as the color of the second display area in another previous step is displayed as another color, and the input of the color set as the color of the second display area in the previous step is performed. The average value of the measurement data and the measurement data related to the input of the color set as the color of the second display area in the other previous step is used as the measurement data related to the input, and the average value of the three primary colors constituting the single color of the second display area is used. By adjusting each luminance value, the color of the first display area and the And setting the color of the display area so as to be closest to each other, and obtaining the input / output characteristics using the luminance values of the three primary colors constituting the single color of the second display area as measurement data relating to the output at that time. Thus, the input / output characteristics of the display device are required, thereby achieving the above object.

In adjusting the luminance values of the three primary colors constituting the single color of the second display area, two of the three primary colors are separated from the other one to separate the two primary colors. It is preferable that the adjustment be performed in conjunction with the luminance value, and that the fine adjustment of the three colors be performed after a certain degree of adjustment has progressed.

In the second display area, a plurality of color patches are arranged on a two-dimensional plane, and the luminance value of one of the three primary colors constituting a single color is increased or decreased along one axis, while the remaining color patches are increased. By arranging the luminance values of the two colors increasing or decreasing along the other axis orthogonal thereto, a color patch which looks closest to the first display area is selected from the plurality of color patches. It is preferable that the luminance values of the three primary colors constituting the single color of the selected color patch be used as the measurement data relating to the output.

A display device according to the present invention is a display device whose input / output characteristics are measured by the input / output characteristic measuring method of the display device according to the present invention, wherein the first display area and the second display area are displayed on a display screen. Is displayed, and the luminance values of the three primary colors constituting the single color of the second display area are adjusted to set the colors of the first display area and the colors of the second display area so that they appear closest.
There is provided a calibration unit that obtains input / output characteristics using the respective luminance values of the three primary colors constituting the single color of the second display area as measurement data relating to output, thereby achieving the above object.

According to the image correction method for a display device of the present invention, a parameter for image correction is calculated based on measurement data of input / output characteristics obtained by the input / output characteristic measurement method for a display device of the present invention, and the parameter is used. Thus, the image is subjected to color correction, thereby achieving the above object.

According to the method of preparing an ICC profile of a display device of the present invention, data for an ICC profile is prepared based on input / output characteristic measurement data obtained by the input / output characteristic measuring method of the display device of the present invention, and the data is created. Using IC
A C profile is created, which achieves the above object.

Preferably, the ICC profile is updated based on the data for the ICC profile.

An image correction parameter is calculated based on input / output characteristic measurement data obtained by the display device input / output characteristic measurement method of the present invention, and an original image and an image corrected using the parameter are displayed. Display them on the screen at the same time,
It is preferable to adjust the data constituting the ICC profile while comparing the two images.

The storage medium of the present invention stores the procedure of the input / output characteristic measuring method of the display device of the present invention or the procedure of the image correcting method of the display device of the present invention, thereby achieving the above object. .

Hereinafter, the operation of the present invention will be described.

According to the present invention, a first display area in which white and black color patches are arranged at the same ratio is compared with a second display area in which a single color patch consisting of three primary colors is displayed. In the second display area, R,
By adjusting and setting each of the luminance values of G and B, it is possible to measure a gray RGB value that is intermediate between white and black. At this time, if the luminance values of R, G, and B are not balanced, a color shift that looks like a gray color, which should be monotone, occurs, and the white balance is lost. Even in such a case, R,
By adjusting each of the luminance values of G and B, it is possible to use not a hardware-level luminance value but a RGB-balanced value as seen by human eyes. The luminance characteristic curve can be measured. By repeating the calibration in this way, it is possible to obtain measurement data representing the input / output characteristics of the display device.

First, using the luminance values of 0 (black) and 255 (white), an intermediate input value 128 is displayed in the first display area.
(Gray) is arranged and displayed at the same ratio so as to be seen, and the output value is measured by adjusting the luminance value of the second display area so that the appearance matches the appearance, and the input / output characteristics are obtained. . Further, using the luminance value of 128 measured as 0, a color corresponding to the intermediate 64 is created to obtain the input / output characteristics,
Similarly, a color corresponding to 192 in the middle is created from the luminance value of 128 measured as 255 and the input / output characteristic is obtained.
・ ・ 、、 By repeating the measurement, up to 2
56 levels of input / output characteristics can be obtained. This makes it possible to accurately measure the input / output characteristics of a display device such as a CRT or a liquid crystal display device using only software.

At this time, if the brightness values of R, G, and B are freely changed, the degree of freedom is too high, and it takes a long time to measure.
Accordingly, the two color components (for example, R and G) of the three primary colors are separated from the other one color component (for example, B), and the luminance values of the two colors (for example, R and G) are linked to each other. It is preferable to adjust the values and fine-tune all the components of the three colors (R, G, B) after a certain degree of adjustment.

Further, a plurality of color patches are arranged on a two-dimensional plane, and the luminance value of one color (for example, B) is increased or decreased along one axis (for example, the X axis), and two colors (for example, R and By increasing or decreasing G) along the other axis (for example, the Y axis), the number of objects to be compared increases, and each luminance value can be easily adjusted.

Based on the data measured in this manner, how the evaluation image is corrected is simulated, and the corrected image is compared with the original image.
It becomes possible to finely adjust the measurement data. Further, at this time, not only the measured data but also all the data constituting the ICC profile (for example, the contents of tags such as a creator and a comment) can be adjusted.

Further, the input and output are inversely converted from the input / output characteristic data measured in this manner,
Data for the C profile can be created. The gamma data of the ICC profile can store not only a gamma value but also a gamma characteristic as a table of up to 32 bits. Therefore, for example, a gamma table having a maximum of 256 levels measured as described above can be stored. Is enough. Therefore, it is possible to perform highly accurate image correction and create an ICC profile. Further, at this time, the data may be graphed so that the user can directly confirm or correct the data.

As described above, the data of the measured input / output characteristics is matched with the data when the change from black to white is linear, so that it is necessary to actually convert the data based on this. However, it is also possible to create data for an ICC profile based on the measured data, create a new ICC profile and save it, or save it in a format (PNG, TIFF, etc.) that can incorporate the ICC profile. When the ICC profile is built in this way, the application is used to perform color conversion using the built-in profile and the profile for another output device, so that the color tone is similar to that seen in the environment in which the original image was created. Therefore, the validity in another machine or an environment using a different ICC profile can be confirmed.

It should be noted that even when the present invention is used, not all data can be measured by the user. In addition, if only the absolutely necessary information is provided, it is possible to create an ICC profile without any updating means. However, the chromaticity ranges of R, G, B, and the white point indicate how the color looks. Is an important factor in specifying the information, it is preferable to prepare it in advance. Therefore, based on the measured input / output data,
Preferably, the ICC profile can be updated.

[0030]

Embodiments of the present invention will be described below with reference to the drawings.

First, a method of measuring input / output characteristics of a display device (a method of calibration) according to an embodiment of the present invention will be described. FIG. 1A shows a case where only one single color patch (second display area) is displayed. Here, Pat (color patch) A and PatB indicate two color patches constituting the background pattern (first display area), and PatC indicates a single color patch (second display area).

For example, if the screen mode of the display device is a 24-bit mode, and each of R, G, and B is configured with 256 gradations, and it is desired to measure gray, which is intermediate between white and black, PatA is (R, G, B) = (0, 0, 0)
, And PatB is (R, G, B) = (255, 2
55, 255). Then, by arranging white and black at the same ratio, PatA and PatB are arranged so that they appear gray on average as shown in FIG. 1A. For the arrangement of PatA and PatB, see FIG.
As shown in (b), PatA and Pat alternately in pixel units.
A pattern in which B is repeated is the most preferable, but a pattern in which PatA and PatB are repeated for each pixel in the vertical direction of the screen or a pattern in which PatA and PatB are repeated for each dot in the horizontal direction of the screen may be used.

The background pattern composed of PatA and PatB and the color patch PatC can be easily compared by arranging them one on top of the other or by adjoining them. And R, G of PatC,
Adjust each value of B and set appropriately, PatA and PatB
If the color of PatC matches the color (the color that appears on average) and the color of PatC, it is assumed that the luminance change from black to white is linear, and that R, which constitutes a gray component that is an intermediate color between black and white,
G and B values can be obtained.

Here, the initial value of PatC is (128,
128, 128), but a value derived from the data of the original ICC profile may be used, or the value may be derived on the premise of a gamma characteristic.

Further, when the colors formed from PatA and PatB and the color of PatC are made to coincide with each other by increasing and decreasing the luminance values of R, G and B, all the values of R, G and B are freely changed. Then, it takes time to reach a matching color because the degree of freedom is too high. For this reason, first, for example, R and G are linked to separate the (R, G) component and the (B) component and adjust each value.
It is preferable to finely adjust all the components G, B and B.

If the number of color patch data is too small, the number of objects to be compared decreases and it becomes difficult to adjust the color. Therefore, as shown in FIG. 2, a plurality of single-color color patches P0 to P8 may be provided. In this case, for example, (R, G) is set in the Y-axis direction (screen vertical direction), and (B) is set in the X-axis direction (screen horizontal direction), and a plurality of color patches can be arranged on the coordinate system.

For example, as shown in FIG.
A color patch PatC of current interest is arranged at at4, a color patch obtained by reducing only the B component from Pat4 is arranged at Pat1, and a color patch obtained by increasing only the B component from Pat4 is arranged at Pat7. Also, Pat
In 3, a color patch in which both the R component and the G component are increased from Pat4 is arranged. In Pat5, a color patch in which both the R component and the G component are reduced from Pat4 is arranged.

Here, Pat4 = PatC = (128,
Assuming that the change amount of R is D [r], the change amount of G is D [g], and the change amount of B is D [b], Pat0 = (128 + D [r], 128 + D [g] , 1
28-D [b]), Pat1 = (128, 128, 128-D [b]), Pat2 = (128-D [r], 128-D [g], 1
28-D [b]), Pat3 = (128 + D [r], 128 + D [g], 1
28), Pat4 = (128,128,128), Pat5 = (128-D [r], 128-D [g], 1
28), Pat6 = (128 + D [r], 128 + D [g], 1
28 + D [b]), Pat7 = (128, 128, 128 + D [b]), Pat8 = (128−D [r], 128−D [g], 1
28 + D [b]). However, if any of the calculated values of R, G, and B is less than 0, a value obtained by subtracting the value from 256 is used.
If it becomes 56 or more, the value is obtained by subtracting 256. D [r], D [g], and D [b] may be the same or different, and may be changed according to the value of Pat4.

To adjust each luminance value, for example, if the scroll button is pressed and scrolled to the right, all displayed (B) components increase, and if scrolled to the left, the (B) components become Decrease and scroll up to get R
If the settings are made such that the components of G and G increase and the components of R and G decrease when scrolled down, the user (user) can easily handle it intuitively.

Alternatively, as shown in FIG. 3, a new P4 may be set by clicking any of P0 to P8 using a pointing device such as a mouse or a pen without scrolling. In this case, the color of the selected color patch is arranged at the center of the screen as a new P4, and the relationship with the surrounding color patches can be the same as before the change.

Further, fine adjustment of R, G, and B can be performed after a certain degree of adjustment is performed by linking the two colors.
For example, in the above example in which R and G are linked and B is adjusted, if the adjustment has progressed to some extent, leave B as it is, take R in the Y-axis direction, and take B in the X-axis direction. Similar adjustments are made by arranging a plurality of color patches on a coordinate system. If necessary, correction may be made while changing the way of taking such axes as R and B, R and G, G and R, etc., until satisfactory.

In this manner, gray (input values (128, 128, 12
An output value (R128, G128, B128) is obtained from a single color patch whose appearance matches that of 8)).

Next, between the black and white, 1/4 gray near the black side is measured. Similarly to the above, the color patch of black (0, 0, 0) and the measured gray (R128, G128, B1)
By comparing and selecting a background pattern in which the color patches of the color patch 28) are arranged to have the same ratio and a single color patch, 1/4 gray (input value (64, 6
4, 64)) are measured (R64, G64, B64).

As described above, the background pattern in which the black (0,0,0) color patches and the measured gray color patches are arranged so as to have the same ratio is compared with the single-color color patch and selected. By doing so, it is possible to measure the input / output characteristics of a color intermediate between black and gray, and to obtain white (255, 25
5,255) and a measured gray color patch are compared and selected from a background pattern in which the ratios are the same, and a single color patch is selected, so that an intermediate color between white and gray is selected. Input / output characteristics can be measured.

As described above, a highly accurate linear gray scale pattern can be obtained by repeatedly selecting color patches whose appearance matches the background pattern. Therefore, it is possible to obtain the respective luminance characteristics of R, G, and B of the display device having the display characteristics that cannot be determined only by the gamma value.

Since the luminance characteristics obtained here are based on the above-described linear characteristics, it is necessary to convert data when performing image correction or creating an ICC profile using the linear characteristics. There is.

The ICC profile is usually handled as a file, but can be embedded in actual image data. For example, a PICT (Quick Draw Pic)
cure), EPS (Encapsulated Po)
st Script), TIFF (Tag Image)
File Format), PNG (Portable)
e Network Graphics). The ICC profile usually includes header information as shown in Table 1 below and Table 2 below.
And a tag as shown in FIG.

[0048]

[Table 1]

[0049]

[Table 2]

Of these, header information is essential,
Even if there is no tag at all, it is appropriate as an ICC profile. The tag is composed of a count (the number of data), the type of data, and actual data. Since as many as 40 types of tags are prepared, only a part of them is shown in Table 2. Normally, 8 tags shown in Table 2 above + copyri
Ght tag + text information tag are often provided. However, grayTRCTTag is rarely used.

The data for the luminance characteristic curve (rTRC, gTRC, bTRC) of such an ICC profile is derived by performing an inverse conversion for exchanging the input and the output on the data measured as described above.

It is assumed that the input / output characteristic of the reference component is 1: 1 based on one color component (for example, G component) among the data calculated by performing the visual measurement in this manner. This is because a reference is required when performing color correction of an image. For the G component, both the input and output are output values, and the other two color components (R component and B component)
For, the output value of the G component for only the input characteristics while keeping the output characteristics unchanged is used as a new input component. Based on this, a table of 255 stages for each of R, G, and B can be created by performing linear interpolation or spline interpolation for values that have not been measured, and the image data is appropriately corrected using the table. be able to.

For example, when PatA and PatB are white and black, and the input / output characteristics of the intermediate gray (128, 128, 128) are measured, the luminance value of PatC is (R1
28, G128, B128), then G
For components, the input / output relationship is (input value, output value) =
(128, G128), for the R component, the input / output relationship is (input value, output value) = (128, R128), and for the B component, the input / output relationship is (input value, output value) = (12
8, B128). At this time, if the conversion is performed on the assumption that the G component is linear, the G component becomes (128, 12
8), the R component is (G128, R128), and the B component is (G128
128, B128). A calculation result obtained by performing such conversion for all measurement points can be used as a parameter for image correction.

For example, when measurement data of the input / output characteristics as shown in FIG.
A conversion table for correction as shown in FIG. 5 is obtained. In these figures, the horizontal axis represents input and the vertical axis represents output. 4 and 5, the upper curve shows an input / output conversion table for R and G, and the lower curve shows B / B.
2 shows an input / output conversion table of FIG.

(Embodiment 1) FIG. 6 is a block diagram for explaining an ICC profile creation method according to an embodiment of the present invention. First, the measurement data 101 as described above is obtained by the calibration unit 100. The calibration unit 100 is a part that displays a screen as shown in FIG. 3 to the user, switches the background pattern one after another, and displays a single color patch that looks like it.

Next, the measurement data 101 is sent to the ICC profile generation means 102. The ICC profile generating means 102 outputs necessary information as a file in accordance with the format, and converts the measurement data 101 by performing the above-described inverse conversion of input and output. For example, by exchanging the input and output of the characteristic data as shown in FIG. 4, an ICC profile conversion table (the horizontal axis is input and the vertical axis is output) as shown in FIG. 7 is created. Using this table, based on the ICC profile 103 previously created or prepared by the manufacturer,
Create a new ICC profile 104. In this case, the ICC profile has been updated, but a new one can be created.

(Embodiment 2) FIG. 8 is a block diagram for explaining an ICC profile creation method and an image correction method according to another embodiment of the present invention. First, the measurement data 101 as described above is obtained by the calibration unit 100.

Next, the measurement data 101 is sent to both the ICC profile generation means 102 and the data adjustment means 105.

In the ICC profile generating means 102,
As in the first embodiment, the input / output reverse conversion is performed to convert the measurement data 101, and a new ICC profile 104 is created based on an ICC profile 103 created before or prepared by a manufacturer.

On the other hand, the measurement data 101 sent to the data adjusting means 105 is used when converting the evaluation image 108. In the image correction means (image correction means) 106,
The correction is performed by converting the image data on a pixel-by-pixel basis based on the image correction input / output conversion table. The data adjusting means 105 is a means for providing a control point on the curve of the input / output characteristics, and correcting the curve itself by moving the point using a pointing device.

The corrected image and the original image (image before correction) 108 are displayed on the display screen of the display device 107, and the data adjusting means 10 compares the two images with each other.
5 converts the input / output characteristics as intended by the user. Using the information, the video correction unit 106 converts the original image into a display image reflecting the input / output characteristics again, and changes the display image in a region where the corrected image is displayed. It is possible to repeatedly perform such image correction by the data adjustment unit 105 and the video correction unit 106.

For example, as shown in FIG. 9, the original image is displayed in the upper left area of the screen, and the image after the color conversion is displayed in the upper right area of the screen. For example, in FIG. 9, the lower curve indicates B, and the upper curve indicates R and G. In the lower left area of the screen, the header information and main tag information of the ICC profile are displayed so that they can be changed as appropriate, and in the lower right area of the screen, data obtained by converting the measurement data for the ICC profile (for example, 7) is displayed.

Further, in this embodiment, in order to independently change the values of R, G, and B, the R, G, and B selection buttons below the lower right display area are pressed and pressed. It is possible to adjust the curve of a certain color component.

In this manner, how the image is converted based on the measured data is displayed, and fine adjustment of the measured data can be performed again while watching the display, and the ICC profile can be obtained from the adjusted measured data. Parameters can be created.

As described above, the CR
It is possible to create accurate parameters when performing calibration of T, a liquid crystal display device, and the like, and pass them to the ICC profile generation unit 102 and the image correction unit 106.

Further, as shown in FIG. 10, based on the newly created ICC profile 104, an ICC profile is embedded in the image data 110 by the image data creating means 109 having the built-in ICC profile 109, and the ICC profile is embedded. Image data (PN
G, TIFF, etc.). The image data creation means 109 is composed of reading and writing routines corresponding to the image format, and serves as a part for embedding the data of the ICC profile in the image file when storing the adjusted image.

Hereinafter, the first and second embodiments will be described.
The specific procedure of the calibration common to the above will be described with reference to the flowchart of FIG.

First, in step 1, an initial value is set. Here, two colors constituting the background pattern (first display area) are PatA and PatB, and their input values are PatA_n = 255 and PatB_n = 0. R
[255], G [255], and B [255] indicate luminance values when each input signal is 255, each of which is 2
55 is substituted. Also, R [0], G [0], B [0]
Indicates a luminance value when each input signal is 0, and 0 is substituted for each.

Next, in step 2, the background pattern is displayed on the display screen. At this time, PatA and PatB
Are arranged in the same ratio so that they appear gray on average. In the present embodiment, PatA and PatB are arranged as shown in FIG.

Next, in step 3, an initial value of the single color patch PatC (second display area) is set.
Here, PatC_n is an input luminance value to be obtained,
The average value (intermediate value) of atA_n and PatB_n.
Further, the color constituting PatC is R [PatC_n].
Is the average value of R [PatA_n] and R [PatB_n], and G [PatC_n] is G [PatA_n] and G [PatA_n].
As an average value with [PatB_n], B [PatC_n]
Is the average value of B [PatA_n] and B [PatB_n]. These values are merely initial values, and initial values can be set based on an original ICC profile provided by a maker or previous measurement data.

Next, in step 4, PatC is placed adjacent to the background pattern PatA or PatB, or displayed on the background pattern as shown in FIG. 1 (a). Further, when displaying a plurality of single color patches, in addition to PatC, the surrounding color patches are also displayed. At this time, the colors of the peripheral color patches can be easily derived from the RGB values of the central PatC.

For example, when nine single-color patches are displayed as shown in FIG. 2, Pat0 = (R [PatC_n] + D [r], G [Pa
tC_n] + D [g], B [PatC_n] -D
[B]), Pat1 = (R [PatC_n], G [PatC_
n], B [PatC_n] -D [b]), Pat2 = (R [PatC_n] -D [r], G [Pa
tC_n] -D [g], B [PatC_n] -D
[B]), Pat3 = (R [PatC_n] + D [r], G [Pa]
tC_n] + D [g], B [PatC_n]), Pat4 = (R [PatC_n], G [PatC_
n], B [PatC_n], Pat5 = (R [PatC_n] -D [r], G [Pa
tC_n] -D [g], B [PatC_n]), Pat6 = (R [PatC_n] + D [r], G [Pa
tC_n] + D [g], B [PatC_n] + D
[B]), Pat7 = (R [PatC_n], G [PatC_
n], B [PatC_n] + D [b]), Pat8 = (R [PatC_n] -D [r], G [Pa
tC_n] -D [g], B [PatC_n] + D
[B]). However, if any of the calculated values of R, G, and B is less than 0, the value is subtracted from 256, and if it is 256 or more, the value is obtained by subtracting 256.

Next, in step 5, when a plurality of single color patches are displayed, the color closest to the background pattern (intermediate color between PatA and PatB) as viewed from the user is selected from the single color patches. select. If there is only one single color patch, the color is changed only by the scroll button.

If it is determined in step 6 that the color has not yet approached, the process returns to step 7 if it is determined.

In step 3, when there is only one single color patch PatC as shown in FIG. 1A, a new color is displayed by changing the luminance value. When a plurality of single color patches are used as shown in FIG.
The luminance value of each color patch is changed. When a new color is displayed, the components are separated such as the (R, G) component and the (B) component, and the two components are adjusted in association with each other. It is preferable to finely adjust all the components G and B.

In step 7, if it is completed, step 9
Go to and write out the measurement data. Here, as input / output measurement data, (128, R128), (128, G1
28), (128, B128) are obtained. At this time,
The measurement data is stored in the memory. If the process has not been completed in step 7, the process proceeds to step 8.

In step 8, PatA and PatB are newly set. The characteristics that are known at this time are 0 and 255 as input values, and the combination of the input value and the output value of the color whose input / output characteristics have been measured so far.
And PatB, and return to step 2.

[0078]

As described in detail above, according to the present invention,
A profile can be created according to the installation environment of the display device without preparing expensive measuring equipment on the user side. Further, even in a display device such as a liquid crystal display device in which the input / output characteristics cannot be expressed only by the gamma value or the gamma characteristics, the input / output characteristics can be accurately measured and a profile can be created. Further, the profile can be easily updated in response to the aging of the display device. Furthermore, before applying the profile, the image is converted in advance, and the characteristics of the created profile can be predicted and appropriately adjusted by comparing the image before and after the conversion.

[Brief description of the drawings]

FIG. 1A is a diagram for explaining color matching in a method of measuring input / output characteristics of a display device according to an embodiment of the present invention, and FIG. 1B is a diagram illustrating an example of the arrangement of PatA and PatB. It is.

FIG. 2 is a diagram for explaining color matching in a method of measuring input / output characteristics of a display device according to another embodiment of the present invention.

FIG. 3 is a diagram for explaining color selection using a pointing device in a display device input / output characteristic measurement method according to another embodiment of the present invention.

FIG. 4 is a graph showing an example of input / output characteristics of measurement data obtained by the present invention.

FIG. 5 is a graph showing an example of a correction conversion table obtained by the present invention.

FIG. 6 is a block diagram for describing an ICC profile creation method according to the first embodiment.

FIG. 7 is a graph showing an example of an ICC profile table obtained by the present invention.

FIG. 8 is a block diagram for describing an ICC profile creation method and an image correction method according to a second embodiment.

FIG. 9 is a diagram for explaining adjustment of ICC profile data in an ICC profile creation method according to an embodiment of the present invention.

FIG. 10 is a diagram for describing image data containing an ICC profile created according to the present invention.

FIG. 11 is a flowchart illustrating calibration using the present invention.

[Explanation of symbols]

REFERENCE SIGNS LIST 100 Calibration unit 101 Measurement data 102 ICC profile generation unit 103 Previous ICC profile 104 New ICC profile 105 Data adjustment unit 106 Image correction unit 107 Display device 108 Evaluation image 109 Image data generation unit with built-in ICC profile 110 Image data 111 Image data creation means with built-in ICC profile PatA, PatB Color patches constituting background pattern PatC, Pat0, Pat1, Pat2, Pat3,
Pat4, Pat5, Pat6, Pat7, Pat8
Single color patch

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuhisa Nakamura 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) Inventor Sadahiko Higami 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Incorporated (72) Inventor Rui Sakuta 22-22 Nagaikecho, Abeno-ku, Osaka City, Osaka F-term (reference) 2G020 AA08 DA05 DA16 DA35 DA65 5C082 AA01 AA37 BA34 BB53 BD02 CA12 CA81 CB05 CB08 DA73 DA87 EA20 MM10

Claims (9)

[Claims] 1. A first display area in which an arbitrary one color patch and an arbitrary one color patch different therefrom are arranged at the same ratio and displayed so as to appear as an intermediate color of two colors;
A method for measuring the input / output characteristics of the display device by comparing the input and output characteristics with a second display area displaying a single color patch, wherein black is displayed as one of the two colors of the first display area,
White is displayed as another color, and the average value of the luminance values of the three primary colors constituting black and the luminance values of the three primary colors constituting white is used as the measurement data relating to the input. The luminance values of the three primary colors constituting a single color are adjusted so that the color of the first display area and the color of the second display area are viewed closest to each other, and the single color of the second display area at that time is set. After performing the first step of obtaining the input / output characteristics using the respective luminance values of the three primary colors constituting the output as measurement data relating to the output, black or white is displayed as one of the two colors of the first display area. The color set as the color of the second display area in the previous step is displayed as one of
The average value of each luminance value of the primary colors and the measurement data relating to the input of the color set as the color of the second display area in the previous step is used as the measurement data relating to the input, and the three primary colors constituting the single color of the second display area Are set so that the color of the first display area and the color of the second display area look closest to each other, and each of the three primary colors constituting the single color of the second display area at that time is adjusted. A second step of obtaining input / output characteristics using the luminance value as measurement data relating to output; and setting one of the two colors of the first display area as a color of the second display area in the previous step. Displaying, displaying another color set as the color of the second display area in another previous step as another color, and measuring the input of the color set as the color of the second display area in the previous step. Data and the second display area in the other previous step The average value of the measurement data relating to the input of the color set as the color is defined as the measurement data relating to the input, and the luminance values of the three primary colors constituting the single color of the second display area are adjusted to adjust the color of the first display area to the color of the first display area. A third step of setting the colors of the second display area so as to look closest to each other, and obtaining input / output characteristics as the measurement data relating to the output using the luminance values of the three primary colors constituting the single color of the second display area at that time; And a method for measuring the input / output characteristics of the display device by repeatedly obtaining the input / output characteristics of the display device. 2. When adjusting each luminance value of three primary colors constituting a single color of the second display area, a component of two of the three primary colors and a component of another color are separated from each other. The method for measuring input / output characteristics of a display device according to claim 1, wherein the adjustment is performed in conjunction with the luminance values of the colors, and the fine adjustment of the three colors is performed after a certain degree of adjustment has progressed. 3. In the second display area, a plurality of color patches are arranged on a two-dimensional plane, and a luminance value of one of three primary colors constituting a single color is increased or decreased along one axis, and The luminance values of the remaining two colors are arranged so as to increase or decrease along the other axis orthogonal to the other two colors, and among the plurality of color patches, the color patch that is the color closest to the first display area is determined. 3. The input / output characteristic measuring method for a display device according to claim 1, wherein the luminance values of three primary colors constituting a single color of the selected color patch are selected as measurement data relating to output. 4. A display device whose input / output characteristics are measured by the input / output characteristics measurement method for a display device according to claim 1, wherein the first display area and the first display area are displayed on a display screen. The second display area is displayed, and the luminance values of the three primary colors constituting the single color of the second display area are adjusted so that the color of the first display area and the color of the second display area look closest. And a calibration unit that obtains input / output characteristics using the luminance values of the three primary colors constituting the single color of the second display area at that time as measurement data relating to output. 5. A parameter for image correction is calculated based on measurement data of input / output characteristics obtained by the input / output characteristics measurement method for a display device according to claim 1. An image correction method for a display device that performs color correction of an image using the same. 6. An ICC profile data is created based on input / output characteristic measurement data obtained by the display device input / output characteristic measurement method according to claim 1. An ICC profile creation method for a display device for creating an ICC profile using the same. 7. The method according to claim 6, wherein the ICC profile is updated based on the data for the ICC profile. 8. An image correction parameter is calculated based on measurement data of input / output characteristics obtained by the input / output characteristics measurement method for a display device according to claim 1, and an original image is calculated. The method according to claim 6, wherein the image and the image corrected using the parameter are simultaneously displayed on a display screen, and the data constituting the ICC profile is adjusted while comparing the two images. 9. A storage medium storing a procedure of the input / output characteristic measuring method for a display device according to claim 1 or a method for correcting an image of a display device according to claim 5.