JP4830359B2 - Color monitor calibration method, color monitor calibration program, color monitor color management system, etc. - Google Patents

Description

  The present invention relates to a color monitor calibration method for adjusting color reproduction and gradation reproduction characteristics of a color monitor to a desired state when performing color management using the color monitor.

  In recent years, the characteristics of various devices (output devices) such as input devices such as scanners and digital cameras, display devices such as color monitors, and printing devices such as printers have been grasped, and the properties are described in a file. A technique called color management that uses and matches the colors of various devices has become common. This color management is generally performed according to the ICC standard advocated by the ICC (International Color Consortium). In the ICC, a characteristic file is called a profile.

  In order to perform color management of a color monitor, in order to perform color conversion between a color space (RGB) that depends on the characteristics of the color monitor and a color space that does not depend on a device (CIEXYZ, CIELab, etc.) As calibration, a white monitor for adjusting white chromaticity, luminance, and the like, and tone reproduction characteristics are adjusted, and then a color monitor profile is created. It should be noted that the applicant has filed a patent application (Japanese Patent Application No. 2004-0662602) regarding a color monitor calibration and profile creation method.

  The white color measurement used as a reference for the white adjustment, the white color measurement displayed on the color monitor screen, the gray scale displayed on the color monitor screen for adjusting the gradation reproduction characteristics, etc. It is necessary to perform color measurement of the color patches, and when creating the profile, it is necessary to perform color measurement of the three primary colors RGB for color conversion.

  As a method of performing such colorimetry, it is roughly divided into <1> a method of visual observation. <2> A method using a contact-type colorimeter. <3> A method using a non-contact colorimeter. There is.

  <1> According to the visual method, since no special equipment is required, it is inexpensive and the influence of ambient light (the influence of illumination light in the measurement environment) can be reflected in calibration and profile creation. There is an advantage that you can. For example, Patent Document 1 discloses a technique for adjusting tone reproduction characteristics by matching a dither image and a continuous tone image.

  <2> In the method using the contact-type colorimeter, target values for white and gradation reproduction characteristics are determined, color patches of predetermined RGB values are displayed on the color monitor screen, and the colorimetric values are measured. The color monitor is adjusted or the video card is adjusted so as to approach the target value, and a profile is created. According to this method, the colorimeter itself is brought into contact with a colorimetric object (an object having a white color as a reference, a color monitor screen), so that stable measurement with high reproducibility can be performed and the environment can be measured. There is an advantage that it is possible to measure the inherent display characteristics of a color monitor device that eliminates the influence of light (the influence of illumination light in the measurement environment).

  <3> According to the method using a non-contact colorimeter, there is an advantage that stable measurement can be performed while reflecting the influence of ambient light (the influence of illumination light in the measurement environment) in calibration and profile creation.

Japanese Patent Application Laid-Open No. 2004-228561 relates to a method of creating a profile using the same reference value for a white reference value used for color monitor calibration and a white reference value used for profile creation. The technology is disclosed.
Japanese Patent Laid-Open No. 6-35430 JP 2005-094400 A

  In the calibration and profile creation in the color management of the conventional color monitor described above, any one of the three colorimetric methods described above is selected and used. However, the three colorimetric methods described above have not only advantages but also disadvantages. That is, the method <1> visual inspection causes individual differences and lacks reproducibility. Further, in the method using the <2> contact colorimeter, the influence of ambient light (the influence of illumination light in the measurement environment) cannot be reflected in calibration and profile creation. <3> In the method using a non-contact colorimeter, the device body is very expensive compared to the contact-type colorimeter, and the distance between the non-contact colorimeter and the screen of the color monitor, the screen Such as the angle of the angle affects the colorimetric value. Further, since the influence of ambient light is reflected, the inherent display characteristics inherent to the color monitor device cannot be obtained.

  Therefore, when a single color measurement method is used for color management of a color monitor, none of the color measurement methods have the above-mentioned drawbacks and are not optimal color measurement methods.

  On the other hand, the optimum in accordance with the processing in each stage performed at the time of calibration and profile creation described above (for example, colorimetry of white color and gradation reproduction characteristics in calibration, colorimetry of RGB three primary colors in profile creation) It is also possible to select and use a colorimetric method for each process, but in that case, two colorimeters, a non-contact colorimeter and a contact colorimeter, are required. In particular, the non-contact type colorimeter is very expensive and therefore expensive.

  Therefore, the present invention has been made in view of the above-described problems. At each stage performed in the color management system (calibration and profile creation) of the color monitor, each stage is selected from various colorimetry methods. It is an object of the present invention to provide a color monitor management method and a color management system that perform optimum colorimetry according to the purpose using a single colorimeter.

In order to solve the above-mentioned problem, the invention according to claim 1 is a color monitor calibration method using one colorimeter, wherein a reference object having white as a reference irradiated with ambient light is used as the reference object. The colorimetry is performed to obtain a standard colorimetric value as a standard white colorimetric value, and the white color displayed on the color monitor irradiated with the ambient light A colorimetric value acquisition step of acquiring a monitor colorimetric value as a white colorimetric value displayed on the color monitor by performing colorimetry with a colorimeter; and the monitor colorimetric value and the reference colorimetric value A white color adjusting process for adjusting the color of the color monitor so as to match, and a color reproduction displayed by measuring the color patch displayed on the color monitor with the colorimeter 1 while the ambient light is blocked It possesses the gradation reproduction characteristic adjusting step of adjusting, to, The measurement position of the first colorimeter when measuring the white color displayed on the color monitor with the first colorimeter is the size of the white spot displayed on the color monitor and the color monitor. The angle of the display screen and the colorimeter of the one, the angle of the color monitor display screen and the illumination light source that produces the ambient light, and the colorimetric unit in the colorimeter and the direction of the illumination light It is determined based on the length of the end of the one colorimeter .

According to this, the monitor colorimetric value as the white colorimetric value displayed on the color monitor and the reference colorimetric value as the reference white colorimetric value are obtained by reflecting the influence of the ambient light. On the other hand, in the case of tone reproduction characteristics, color measurement is performed without being affected by ambient light so that the expression characteristics unique to the color monitor can be adjusted. At each stage, it is possible to perform a colorimetry suitable for each processing stage with a single colorimeter from among various colorimetry methods, which is optimal for the purpose of each stage. In addition, since only the white part displayed on the color monitor can be measured in a state that prevents the shadow of the colorimeter from being reflected, the colorimetric value of the monitor can be measured more precisely, and the white color can be measured more accurately. Can be adjusted.

  In order to solve the above-described problem, the invention according to claim 2 is the color monitor calibration method according to claim 1, wherein the state in which the ambient light is blocked in the gradation reproduction characteristic adjustment step is the color. The colorimeter of the first aspect is in contact with a display screen of a monitor.

  According to this, by performing color measurement in a state in which the colorimeter is in contact with the display screen of the color monitor to be measured, it is possible to perform stable measurement while blocking ambient light.

  In order to solve the above-mentioned problem, the invention according to claim 3 is the color monitor calibration method according to claim 1 or 2, wherein the reference object in the colorimetric value acquisition step is the colorimeter of the first. Display of the color monitor when measuring the distance between the reference object and the first colorimeter and the white color displayed on the color monitor when measuring with the first colorimeter The distance between the screen and the one colorimeter is the same in a range where the influence of the ambient light irradiated on the reference object and the color monitor is equal.

  According to this, since the monitor colorimetric value and the reference white value can be measured more precisely, the white color can be adjusted more accurately.

In order to solve the above-mentioned problem, the invention according to claim 4 is the color monitor calibration method according to any one of claims 1 to 3 , wherein the white color displayed on the color monitor is measured by the first measurement. The distance between the display screen of the color monitor and the first colorimeter when measuring with a colorimeter is L, and the white portion displayed on the color monitor is Px with a horizontal length of Px. It is assumed that the patch is a rectangular white patch having a length in the direction Py, the horizontal angle of the color monitor display screen and the colorimeter 1 is θw, the vertical angle is θh, and the color monitor display The angle between the screen and the light source of the illumination light that produces the ambient light is θl, and the lengths of the colorimetric unit in the first colorimeter and the end of the first colorimeter in the light source direction of the illumination light are Assuming M, the color monitor The distance L between the colorimeter of the display screen 1, and satisfies the following equation (1) to (3).

これによれば、カラーモニタに表示された白色パッチの大きさや、測色器の角度等を考慮しつつ、測色器の影の映り込みを防いだ状態で測色可能に構成したので、モニタ測色値をより厳密に測定でき、より正確に白色を調整することができる。

According to this configuration, the color patch can be measured while preventing the reflection of the shadow of the colorimeter while taking into account the size of the white patch displayed on the color monitor, the angle of the colorimeter, etc. Colorimetric values can be measured more precisely, and white can be adjusted more accurately.

To solve the above problems, the invention according to claim 5, profile A method for producing a color monitor to be performed after the calibration by the calibration method for a color monitor according to any one of claims 1 to 4 The color monitor has a step of creating a color monitor profile by measuring each of the plurality of color patches displayed on the color monitor with the first colorimeter in a state where the ambient light is blocked. To do.

According to this, it is possible to create a profile using the same colorimeter while reflecting the effect of the invention according to any one of claims 1 to 4 .

In order to solve the above problem, the invention according to claim 6 is the color monitor profile creation method according to claim 5 , wherein the state where the ambient light is blocked is that the display screen of the color monitor displays the first item. The colorimetric device is in contact with the colorimeter.

  According to this, by performing color measurement in a state in which the colorimeter is in contact with the display screen of the color monitor to be measured, it is possible to perform stable measurement while blocking ambient light.

According to the present invention, at each stage performed during color management of a color monitor, among various colorimetry methods, an optimum colorimetry method according to the purpose of each stage is used. Can be performed with a single colorimeter. Also, the monitor colorimetric value can be measured more precisely, and the white color can be adjusted more accurately.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings. This embodiment relates to a color management system S that performs color measurement suitable for the purpose of each stage using a single colorimeter at each stage of calibration and profile creation in color monitor color management. An example to which the invention is applied is shown.

[Configuration and function of color management system S]
First, the color management system S according to the present embodiment will be conceptually described with reference to FIG.

  FIG. 1 is an explanatory diagram showing a schematic configuration and a usage state of the color management system S according to the present embodiment.

  As shown in the figure, the color management system S includes a color monitor 1 as a color management target, white paper as a reference object having white as a reference, white patches and color patches displayed on the color monitor 1, and the like. And a computer 3 that connects the color monitor 1 and the colorimeter 2 and actually performs processing for calibration and profile creation.

  The color monitor 1 is a display device that performs color reproduction by additive color mixing of the three primary colors R (red), G (green), and B (blue), such as a color CRT, a color liquid crystal display device, and a color plasma display display device. I just need it.

  In this embodiment, the colorimeter 2 uses a contact-type colorimeter that has been commercially available.

  FIG. 2 is a block diagram illustrating a schematic configuration example of the computer 3. As shown in the figure, the computer 3 includes a control unit 31 including a CPU (Central Processing Unit) having a calculation function, a working RAM (Random Access Memory), a ROM (Read Only Memory) storing various data and programs, and the like. And a storage unit 32 as a storage means composed of an HD or the like for storing and storing (storing) white patch data, color patch data, and the like, and an external device connection unit 33, and a control unit 31, The storage unit 32 and the external device connection unit 33 are connected to each other via a bus 34. Then, the control unit 31 performs overall control of the entire computer 3 by reading and executing a calibration / profile creation program (described later) stored in the ROM or the storage unit 32 by the CPU.

  The control unit 31 includes a CPU (not shown), a working RAM, a ROM for storing various control programs including the calibration / profile creation program of the present invention, data, and the like, an oscillation circuit, and the like. Based on the operation signal from the unit, control information for controlling each of the constituent members to realize the operation corresponding to the operation information included in the operation signal is generated, and the control information is transmitted via the bus 34. Is output to the corresponding constituent member to control the operation of each constituent member. In addition, the control unit 31 executes a calibration program and a profile creation program stored in a ROM or the like, thereby cooperating with other constituent members to obtain a colorimetric value acquisition unit, a white color adjustment unit, a gradation It functions as reproduction characteristic adjustment means and profile creation means.

  Here, the calibration program / profile creation program stored in the ROM or the storage unit 32 includes a calibration module for calibrating a color monitor, a profile creation module for creating a color monitor profile, and A setting module for displaying menus for calibration and profile creation, displaying a message for guiding the operator to a predetermined operation, and further displaying a window for requesting the operator to set various parameters. Consists of.

  The external connection unit 33 is used to send an instruction signal to the color monitor 1 via a video card built in the computer 3, a VGA cable, a DVI cable, a BNC cable, or the like. Furthermore, it is configured to receive data from the colorimeter 2 by a serial method, a USB method, IEEE1394, or other appropriate method.

[Color monitor color management]
First, a specific method of color management of a color monitor will be described with reference to FIGS.

  3A is a flowchart showing the color management process of the color monitor, FIG. 3B is a flowchart showing the calibration process, and FIG. 3C is a flowchart showing the white calibration process. FIG. 3D is a flowchart showing the profile creation process. This process is performed by the control unit 31 of the computer 3 executing a calibration program / profile creation program.

  In the color management process of the color monitor shown in FIG. 3A, first, a calibration process is performed (step S11), and then a profile creation process is performed (step S12).

  First, the calibration process in step S11 will be specifically described with reference to the flowcharts shown in FIGS. 3 (B) and 3 (C).

1. Calibration process
1-1. White calibration processing First, white calibration processing is performed to adjust white (step S21). Next, the specific content of the white calibration process in step S21 will be described with reference to the flowchart shown in FIG.

  The control unit 31 of the computer 3 functions as a colorimetric value acquisition unit, and measures the white color of white paper as a reference object having a reference white color by the colorimeter 2 to acquire a reference colorimetric value (step). S31). In this color measurement, the color measurement is performed in a state where the ambient light is applied to the white paper. This ambient light is a state where the light is scattered throughout the space and gives appropriate brightness to the entire measurement chamber. More specifically, it refers to indirect light such as light reflected from an object in the measurement room where the illumination light in the measurement environment (measurement room) actually performs color measurement. Furthermore, depending on the position of the white paper, It may also include direct light directly irradiated onto the paper. Note that white paper is preferably measured in a measurement environment using typical illumination light that is expected to be observed by an actual color monitor. As a result, the tristimulus values (XYZ) obtained as a result of the color measurement by the colorimeter 2 reflect the influence of the illumination light from the white paper.

  Subsequently, the control unit 31 of the computer 3 functions as a colorimetric value acquisition unit and a white color adjustment unit, and sends white patch data stored in advance in the storage unit 32 to the color monitor 1, and the color monitor 1 is transmitted from the computer 3. A white patch based on the received white patch data is displayed, the white patch is color-measured by the colorimeter 2 to obtain a monitor colorimetric value, and white adjustment of the color monitor 1 is performed (step S32), and the process is terminated. To do. In the color measurement of the white patch, the color measurement is performed in a state in which appropriate environmental light is applied to the white patch displayed on the color monitor 1 in the same manner as the color measurement in step S31.

  Here, the white adjustment of the color monitor 1 will be specifically described. First, the reference colorimetric value acquired in step S31 and the monitor colorimetric value acquired in step S32 are obtained from the colorimeter 2 (or the colorimetric value obtained by operating the input unit (not shown) by the user). In the computer 3).

  Then, the calibration module stored in the storage unit 32 compares the reference colorimetric value with the monitor colorimetric value, and determines whether or not the difference between the two is within a predetermined error range. When the calibration module transmits a signal from the control unit 31 to the color monitor 1 via the external connection unit 33 for each of RGB in the external connection unit 33 when it is out of the predetermined error range. A video board (not shown) provided is adjusted, and a white patch having a new white color is displayed on the color monitor 1. At this time, the RGB gradation values output from the control unit 31 remain 255 and are not changed. If the color monitor 1 is an analog format, the gain of the amplifier of the D / A converter provided for each of R, G, and B provided in the external connection unit 33 may be changed and adjusted. When the main body of the color monitor 1 has a monitor display adjustment function, the control unit 31 transmits an RGB adjustment instruction signal to the color monitor 1 via the external connection unit 33, and the color monitor 1 receives the received RGB adjustment. The monitor display may be adjusted based on the instruction signal.

  Subsequently, color measurement is performed on a white patch having a new white color to obtain a monitor colorimetric value, and the process of step S32 is performed until the difference from the reference colorimetric value falls within a predetermined error range. As an example of the predetermined error range, for example, if the reference colorimetric value is (X = 60.7, Y = 62.7, Z = 46.9), the monitor colorimetric value is (X = 60.5). ˜60.9, Y = 62.5 to 62.9, Z = 46.7 to 47.1) (that is, a range of ± 0.2 respectively) is an error range. The reference colorimetric values (X = 60.7, Y = 62.7, Z = 46.9) are described later using a commercially available contact colorimeter (Gretag Macbeth i1) as the measuring instrument 2. A color evaluation D50 fluorescent lamp (HITACHI lunch white color rendering AAA FLR40S N-EDL / M · NU) was used as a light source of illumination light, and the color was measured under test conditions under an illuminance of 520 lux.

  Note that the colorimetry in step S31 and step S32 needs to be performed in a state where the ambient light is applied to the white paper and white patch that are the measurement target (a state in which the influence of the ambient light is reflected), so the colorimetry is performed. It is more preferable that the device 2 is not in contact with the white paper or the display screen of the color monitor 1 and is separated to some extent (non-contact).

  FIG. 4A shows an explanatory diagram of measurement positions when the display screen of the color monitor 1 is measured. According to the example shown in the figure, the colorimeter 2 measures at a position separated from the display screen of the color monitor 1 by a distance L.

  FIG. 4B shows a graph of the distance L between the colorimeter 2 and the color monitor 1 and the colorimetric values (XYZ). As shown in the figure, when the color measurement is performed while changing the distance L, a drop point at which all the values of the X, Y, and Z values that are the colorimetric values start to decrease is obtained. This is due to the fact that the colorimeter 2 also performs color measurement on portions other than the white patch displayed on the color monitor 1, that is, the display screen portion outside the white patch. Therefore, the distance L between the display screens of the colorimeter 2 and the color monitor 1 is preferably closer (smaller) than the distance L ′ corresponding to the descending point.

  Note that the distance L between the colorimeter 2 and the white paper is the distance corresponding to the descent point after obtaining the descent point at which all of the X-value, Y-value, and Z-value, which are colorimetric values, begin to fall in the same manner as above. It is preferably closer (smaller) than L ′. Furthermore, the distance L between the white paper and the colorimeter 2 when measuring white paper, and the display screen and colorimeter of the color monitor 1 when measuring the white patch displayed on the color monitor 1 The distance L to 2 is preferably the same so that the influence of ambient light is equally reflected in the measurement result. Therefore, even if the distance is not exactly the same, the influence of the ambient light irradiated on the white paper reflected in the color measurement result obtained by measuring the white color of the white paper and the color measurement obtained by measuring the white patch displayed on the color monitor 1 are measured. The distance L should be the same as long as the influence of the ambient light applied to the white patch displayed on the color monitor 1 reflected in the color result is the same (equal range). For example, the white color of white paper is measured. When the color is to be measured, the white paper may be placed on the display screen of the color monitor 1 or the color measurement may be performed while standing against the display screen. In this case, it is preferable that nothing is displayed on the color monitor 1 so that light from the display screen of the color monitor 1 is not measured by the colorimeter 2. Furthermore, it is preferable that the measurement position of the colorimeter 2 is a position where the shadow of the colorimeter 2 does not appear on the white paper which is the measurement target or the white patch displayed on the color monitor 1.

1-2. Gradation reproduction characteristic calibration process The gradation reproduction characteristic calibration process performed in step S22 will be described by returning to the flowchart shown in FIG.

  The control unit 31 functions as a tone reproduction characteristic adjusting unit, and sends out the color patch data of the color patch data stored in advance in the storage unit 32 to the color monitor 1, and the color monitor 1 receives the color patch received from the computer 3. A color patch based on the data is displayed, and the color patch is measured by the colorimeter 2 to adjust the gradation reproduction characteristics (step S22). Thereafter, the process ends. This color patch uses, for example, a gray scale having the same value for each of RGB.

  More specifically, the calibration module stored in the storage unit 32 causes the control unit 31 to output RBG values stored in advance in the storage unit 32 (R, G, and B are equal to each other), and to the color monitor 1. Displays a gray scale corresponding to the RGB value. Then, the color scale displayed on the colorimeter 2 is measured, and the obtained colorimetric value is input from the colorimeter 2 (or the colorimetric value obtained by the user operating an input unit not shown). To the computer 3. The calibration module changes the RGB values in various ways, and repeats the gray scale display by the color monitor 1 and the color measurement by the colorimeter 2. The number of gray scale colorimetric values to be obtained can be arbitrarily determined, and the gradation reproduction characteristics can be determined with higher accuracy as the number of gray scales is increased. As another example of the color patch, a single color scale having a plurality of gradations may be used for each of RGB.

  Then, in consideration of the γ characteristic of the γ value (gamma value) for each RGB input by the user operating an input unit (not shown), the γ characteristic of the γ value input as the luminance displayed on the color monitor 1 In accordance with the control of the control unit 31, adjustment is performed on the video board provided in the external connection unit 33, and a lookup table is created for each RGB.

  If the main body of the color monitor 1 has a monitor display adjustment function, the lookup table may be held in the color monitor 1. In this case, the control unit 31 first transmits an RGB adjustment instruction signal based on the γ value input to the color monitor 1 via the external connection unit 33, and the color monitor 1 is based on the received RGB adjustment instruction signal. Make adjustments. Then, the color monitor 1 returns the adjustment result to the control unit 31, and the control unit 31 creates a lookup table for each RGB based on this, and sends the lookup table to the color monitor 1 via the external connection unit 33. The color monitor 1 stores the received lookup table in a memory or the like (not shown) provided in the color monitor 1.

  Note that the color measurement in step S22 is preferably performed in a state where ambient light is blocked in order to measure display characteristics unique to the device of the color monitor 1. As an example, if the colorimeter 2 is in contact (contact) with the display screen of the color monitor 1 to be measured, it is possible to perform stable measurement while blocking ambient light.

  In addition, you may perform the process of step S21 mentioned above and step S22 in any order. That is, after adjusting the tone reproduction characteristics using a desired γ value (step S22), it is possible to perform white adjustment so that all the values of R, G, and B are 255 (step S21). It is.

  Then, returning to the flowchart shown in FIG. 3A, profile creation processing is performed (step S12), and the processing is terminated.

  Next, the profile creation process performed in step S12 will be described in detail using the flowchart shown in FIG.

2. Profile Creation Processing The profile created here is a color for matching the color reproduced on the color monitor 1 with the color reproduced by another device such as a printing press or printer via a device-independent standard color space. Used for conversion.

  By the way, when CIE XYZ as the standard color space is used, signals of gradation values R, G, and B are input to the color monitor 1, and colorimetric values of colors actually displayed on the color monitor 1 at that time are obtained. It is known that X, Y, and Z are expressed as determinants represented by the following formula (4).

式（４）において、Ｘ値、Ｙ値、Ｚ値は、ガンマ値（γ値）γにおいて、ＸＲ、ＹＲ、ＺＲは赤の原色（Ｒ＝２５５、Ｇ＝Ｂ＝０）、ＸＧ、ＹＧ、ＺＧは緑の原色（Ｒ＝０、Ｇ＝２５５、Ｂ＝０）、ＸB、ＹB、ＺBは青の原色（Ｒ＝Ｇ＝０、Ｂ＝２５５）のみが表示された場合の測色色度である。

In equation (4), X value, Y value, Z value are gamma values (γ values) γ, XR, YR, ZR are red primary colors (R = 255, G = B = 0), XG, YG, ZG is the colorimetric chromaticity when only the green primary colors (R = 0, G = 255, B = 0) and XB, YB, ZB are the blue primary colors (R = G = 0, B = 255) are displayed. is there.

  In other words, the expression (4) displays the colorimetric values X, Y, and Z of the colors displayed when the signals having the gradation values R, G, and B are input to the color monitor 1, respectively. This is a conversion formula for converting the color of RGB color space (device-dependent color space) unique to the color monitor 1 into the color of the standard color space of CIEXYZ among the profiles of the color monitor 1.

  Then, the equation obtained by solving equation (4) for R, G, and B exactly converts the color in the standard color space of CIE XYZ into the color of the color space by RGB (device dependent color space) unique to the color monitor 1. This is the conversion formula. Therefore, in the profile creation process performed in step S12, it is first necessary to specify the above formula (4) by the profile creation module.

  In the present embodiment, since the profile creation process is performed after the calibration process, the white calibration process and the gradation reproduction characteristic calibration process do not need to be performed, and are used in the processes in steps S31 and S22. The reference white colorimetric value or γ value that is the reference may be temporarily stored in the storage unit 32, and the profile creation module may be obtained from the storage unit 32. If calibration is not performed, or if it is necessary to measure again due to changes in measurement conditions (changes in the model of the measuring instrument 2 or changes in the effects of ambient light due to changes in illumination light, etc.) It is necessary to perform processing similar to the calibration processing.

  In order to obtain XR, YR, ZR, XG, YG, ZG, XB, YB, ZB in the above formula (4), in the process of FIG. 3D, first, the control unit 31 functions as a profile creation unit, A plurality of color patches indicating the three primary colors RGB displayed on the color monitor 1 are each measured by the colorimeter 2 (step S41).

  Then, white reference colorimetric values and γ values that are temporarily stored in the storage unit 32 and used as the reference in the processing of step S31 and step S22 are acquired (step S42), and based on these, the color monitor 1 is acquired. Is created (step S43), and the process ends. In the case of color measurement, it is desirable to measure in a state where ambient light is blocked in order to measure the display characteristics specific to the device of the color monitor 1 as in the case of the color measurement in step S22. As an example, if the colorimeter 2 is in contact (contact) with the display screen on which the color patch 1 of the color monitor 1 to be measured is displayed, the ambient light is blocked and stable measurement is performed. Can do.

  According to the present embodiment described above, at each stage performed during color management of the color monitor, an optimum colorimetry method according to the purpose of each stage is selected from each of the various colorimetry methods at each processing stage. It is possible to perform suitable colorimetry with a single colorimeter.

  In the above embodiment, the CIEXYZ space is used as the standard color space. However, the present invention is not limited to this, and other color spaces such as the 1976 CIELab space defined by the International Commission on Illumination (CIE) may be used.

[Other variations]
Next, a more preferable color measurement method will be described for the color measurement performed in the white calibration process described with reference to the flowchart of FIG. 3B (step S21) and FIG. 3 (C).

  As described above, in the color measurement in the white calibration process, it is necessary to perform the color measurement in a state where the ambient light is applied to the white patch to be measured (a state in which the influence of the environmental light is reflected). The colorimetric position by the colorimeter 2 is preferably not separated from the display screen of the color monitor 1 and separated to some extent, and the shadow of the colorimeter 2 is reflected on the white patch displayed on the color monitor 1 that is the measurement target. It is preferable that the position does not fall.

  Therefore, the measurement position of the colorimeter 2 when measuring the white color of the white patch displayed on the color monitor 1 is the size of the white spot displayed on the color monitor 1 (in this embodiment). The size of the white patch), the angle of the display screen of the color monitor 1 and the colorimeter 2, the angle of the light source of the illumination light that creates the ambient light and the display screen of the color monitor 1, and the colorimeter 2 It is preferable to determine based on the length of the colorimetric unit and the end of the colorimeter 2 in the illumination light direction.

  An example will be described with reference to FIGS. FIG. 5 is a display example of the color monitor 1 displaying a white patch. 6A to 6C are explanatory diagrams of measurement positions of the colorimeter 2 when the display screen of the color monitor 1 is measured.

  As shown in FIGS. 5 and 6, when the white color of the white patch displayed on the color monitor 1 is measured by the colorimeter 2, the distance between the display screen of the color monitor 1 and the colorimeter 2 is L, The horizontal length of the white patch displayed on the color monitor 1 is Px, the vertical length is Py, the horizontal angle between the display screen of the color monitor 1 and the colorimeter 2 is θw, and the vertical angle Is θh, the angle of the light source of the illumination light that creates the ambient light and the display screen of the color monitor 1 is θl, and the colorimetric unit in the colorimeter 2 and the light source direction of the illumination light (in the case shown in FIG. 6A) If the length from the end of the colorimeter 2 in the direction of the drawing is M, all of the expressions (1) to (3) below the distance L between the display screen of the color monitor 1 and the colorimeter 2 are satisfied. It is desirable.

上記式（１）及び（２）は、カラーモニタ１に表示された白色パッチの大きさを考慮したものであり、式（３）は測色器２のカラーモニタ１への映りこみ防止を考慮したものである。

The above formulas (1) and (2) take into consideration the size of the white patch displayed on the color monitor 1, and the formula (3) takes into consideration the prevention of the reflection of the colorimeter 2 on the color monitor 1. It is a thing.

  As described above, the color measurement position by the color measuring device 2 is determined in consideration of the size of the white patch displayed on the color monitor 1 and the reflection of the color measuring device 2 on the color monitor 1, so that the more accurate. Colorimetry can be performed, and it is possible to perform satisfactory color monitor calibration and profile creation based on this using only one colorimeter.

It is explanatory drawing which shows the outline of a structure of the color management system S which concerns on this embodiment, and a use condition. 2 is a block diagram illustrating a schematic configuration example of a computer 3. FIG. (A) It is a flowchart which shows the color management process of a color monitor. (B) is a flowchart showing a calibration process. (C) is a flowchart which shows a white calibration process. (D) is a flowchart showing a profile creation process. (A) It is explanatory drawing of the measurement position at the time of measuring the display screen of the color monitor 1. FIG. (B) is a graph of the distance L between the colorimeter 2 and the color monitor 1 and the colorimetric values (XYZ). It is the example of a display of the color monitor 1 which displayed the white patch. It is explanatory drawing of the measurement position of the colorimeter 2 at the time of measuring the display screen of the color monitor 1. FIG.

Explanation of symbols

S Color management system 1 Color monitor
2 Colorimeter 3 Computer 31 Control Unit 32 Storage Unit 33 External Device Connection Unit 34 Bus S Color Management System

Claims (14)

In the color monitor calibration method using the colorimeter of No. 1,
A reference color measurement value is obtained as a reference white colorimetric value by measuring the color of a reference object having a reference white color irradiated with ambient light using the first colorimeter. Colorimetry for obtaining a monitor colorimetric value as a colorimetric value of white displayed on the color monitor by measuring the white color displayed on the color monitor irradiated with light with the first colorimeter. Value acquisition process;
A white adjustment step for adjusting the color of the color monitor so that the monitor colorimetric value matches the reference colorimetric value;
A gradation reproduction characteristic adjustment step of adjusting the gradation reproduction characteristic by measuring the color patch displayed on the color monitor with the colorimeter in the state where the ambient light is blocked;
I have a,
The measurement position of the first colorimeter when measuring the white color displayed on the color monitor with the first colorimeter is the size of the white portion displayed on the color monitor and the color monitor. The angle of the display screen and the colorimeter of the one, the angle of the color monitor display screen and the illumination light source that produces the ambient light, and the colorimetric unit in the colorimeter and the direction of the illumination light A color monitor calibration method, wherein the color monitor calibration method is determined based on a length from an end of the one colorimeter . The color monitor calibration method according to claim 1,
The color monitor calibration method according to claim 1, wherein the state in which the ambient light is blocked in the gradation reproduction characteristic adjusting step is a state in which the first colorimeter is in contact with the display screen of the color monitor. The color monitor calibration method according to claim 1 or 2,
In the colorimetric value acquisition step, the distance between the reference object and the first colorimeter and the white color displayed on the color monitor when measuring the reference object with the first colorimeter. The distance between the display screen of the color monitor and the first colorimeter when measuring with the first colorimeter is a range in which the influence of the ambient light irradiated on the reference object and the color monitor is equal. And a color monitor calibration method characterized by the same. The color monitor calibration method according to any one of claims 1 to 3,
When the white color displayed on the color monitor is measured by the colorimeter 1, the distance between the display screen of the color monitor and the colorimeter 1 is L,
The white spot displayed on the color monitor is a rectangular white patch having a horizontal length Px and a vertical length Py.
The horizontal angle of the display screen of the color monitor and the colorimeter 1 is θw, the vertical angle is θh,
The angle of the light source of the illumination light that produces the display screen of the color monitor and the ambient light is θl,
When the length of the colorimetric unit in the one colorimeter and the end of the one colorimeter in the light source direction of the illumination light is M,
A color monitor calibration method , wherein a distance L between the display screen of the color monitor and the first colorimeter satisfies the following equations (1) to (3) .

  In the color monitor profile creation method performed after calibrating by the color monitor calibration method according to claim 1,
  A color having a step of creating a color monitor profile by measuring each of the plurality of color patches displayed on the color monitor with the first colorimeter while the ambient light is blocked How to create a monitor profile.   The color monitor profile creation method according to claim 5.
  The color monitor profile creation method, wherein the state in which the ambient light is blocked is a state in which the first colorimeter is brought into contact with the display screen of the color monitor.   A computer included in a color monitor calibration system using one colorimeter
  A reference color measurement value is obtained as a reference white colorimetric value by measuring the color of a reference object having a reference white color irradiated with ambient light using the first colorimeter. Colorimetry for obtaining a monitor colorimetric value as a colorimetric value of white displayed on the color monitor by measuring the white color displayed on the color monitor irradiated with light with the first colorimeter. Value acquisition means,
  White adjustment means for adjusting the color of the color monitor so that the monitor colorimetric value matches the reference colorimetric value;
  A color monitor that functions as gradation reproduction characteristic adjusting means for adjusting the gradation reproduction characteristic by measuring the color patch displayed on the color monitor with the colorimeter 1 and adjusting the gradation reproduction characteristic with the ambient light blocked. A calibration program,
  The measurement position of the first colorimeter when measuring the white color displayed on the color monitor with the first colorimeter is the size of the white portion displayed on the color monitor and the color monitor. The angle of the display screen and the colorimeter of the one, the angle of the color monitor display screen and the illumination light source that produces the ambient light, and the colorimetric unit in the colorimeter and the direction of the illumination light A calibration program for a color monitor, characterized in that the calibration program is determined on the basis of the length of the one colorimeter.   The color monitor calibration program according to claim 7,
  A color monitor calibration program which causes the gradation reproduction characteristic adjusting means to function as a state in which the color measuring device is in contact with the display screen of the color monitor when the ambient light is blocked .   The color monitor calibration program according to claim 7 or 8,
  When the colorimetric value acquisition unit measures the color of the reference object with the colorimeter, the distance between the reference object and the colorimeter and the white color displayed on the color monitor. The distance between the display screen of the color monitor and the first colorimeter when measuring with the first colorimeter is a range in which the influence of the ambient light irradiated on the reference object and the color monitor is equal. A color monitor calibration program characterized in that it functions so as to be the same.   The color monitor calibration program according to any one of claims 7 to 9,
  When the white color displayed on the color monitor is measured by the colorimeter 1, the distance between the display screen of the color monitor and the colorimeter 1 is L,
  The white spot displayed on the color monitor is a rectangular white patch having a horizontal length Px and a vertical length Py.
  The horizontal angle of the display screen of the color monitor and the colorimeter 1 is θw, the vertical angle is θh,
  The angle of the light source of the illumination light that produces the display screen of the color monitor and the ambient light is θl,
  When the length of the colorimetric unit in the one colorimeter and the end of the one colorimeter in the light source direction of the illumination light is M,
  A color monitor calibration program characterized in that a distance L between the display screen of the color monitor and the first colorimeter satisfies the following formulas (1) to (3).

  A computer functioning by the color monitor calibration program according to any one of claims 7 to 10,
  In a state in which the ambient light is blocked, the plurality of color patches displayed on the color monitor are each measured by the first colorimeter to further function as profile creating means for creating a profile of the color monitor. A color monitor profile creation program.   The color monitor profile creation program according to claim 11,
  The color monitor profile creation program characterized in that the state in which the ambient light is blocked is a state in which the first colorimeter is in contact with the display screen of the color monitor.   A color monitor calibration system using one colorimeter, wherein the color monitor includes a computer connected to be capable of transmitting and receiving information to and from the color monitor.
  The computer
  A reference color measurement value is obtained as a reference white colorimetric value by measuring the color of a reference object having a reference white color irradiated with ambient light using the first colorimeter. Colorimetry for obtaining a monitor colorimetric value as a colorimetric value of white displayed on the color monitor by measuring the white color displayed on the color monitor irradiated with light with the first colorimeter. Value acquisition means,
  White adjustment means for adjusting the color of the color monitor so that the monitor colorimetric value matches the reference colorimetric value;
  Gradation reproduction characteristic adjusting means for adjusting the gradation reproduction characteristic by measuring the color patch displayed on the color monitor with the colorimeter in the state where the ambient light is blocked;
  Have
  The measurement position of the first colorimeter when measuring the white color displayed on the color monitor with the first colorimeter is the size of the white portion displayed on the color monitor and the color monitor. The angle of the display screen and the colorimeter of the one, the angle of the color monitor display screen and the illumination light source that produces the ambient light, and the colorimetric unit in the colorimeter and the direction of the illumination light A color monitor calibration system characterized in that the color monitor calibration system is determined on the basis of a length with respect to an end of the one colorimeter.   14. The color monitor color management system including the color monitor calibration system according to claim 13, wherein the computer includes:
  And a profile creating means for creating a color monitor profile by measuring each of the plurality of color patches displayed on the color monitor with the first colorimeter while the ambient light is blocked. Color monitor color management system.

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