JP2012163486A - Measurement system, display device, measurement device, correction device and measurement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a measurement system, a display device, a measurement device, a correction device and a measurement method, capable of absorbing an individual difference of display devices to perform accurate measurement of display intensity.SOLUTION: A normal measurement value, which is based on the results of previously measuring a standard screen as a standard of display using a measurement device, and a standard measurement value, which is based on the results of previously measuring the standard screen using a measurement device, are recorded in an LUT1 and an LUT2. Then, the display intensity of display screen measured by the measurement device is corrected based on the normal measurement value and the standard measurement value.

Description

  The present application relates to a measurement system, a display device, a measurement device, a correction device, and a measurement method for measuring display on a display screen with a measurement device for the purpose of adjusting display on the display screen of the display device.

  In display devices such as LCD (Liquid Crystal Display) monitors, CRT (Cathode Ray Tube) monitors, PDP (Plasma Display Panel) monitors, organic EL display monitors, electronic paper, etc., by adjusting the image displayed on the display screen, The display in the original display color is realized. For example, display intensity such as the brightness of the image displayed on the display screen of the display device, the stimulus value of the color component, chromaticity, and density is measured by the measuring device, and the display screen is adjusted based on the measurement result. Furthermore, the measurement results are not limited to adjustment of the display screen of the display device, but include various measurement results such as accumulation of measurement results for the purpose of quality control of the display device, notification of measurement results for the purpose of prompting the user to make adjustments, etc. Used for applications.

  When performing such a measurement, it is preferable to use a reference measurement device including a spectral sensor that has a response sensitivity according to a color matching function based on the sensitivity of the human eye and functions as a reference sensor. However, the reference measurement device having such characteristics may be relatively expensive, and a simple sensor that can be obtained at a relatively low cost is used as the measurement device when the measurement is performed by the user. As such a measuring apparatus, for example, a simple sensor such as a tristimulus sensor or a spectral sensor with reduced accuracy is used.

  FIG. 11 is a graph illustrating an example of an error in spectral response sensitivity of the measurement apparatus. FIG. 11 is a graph showing the characteristics of the measuring apparatus with the horizontal axis representing wavelength and the vertical axis representing relative sensitivity. FIG. 11 shows the characteristics of standard light specified by the International Commission on Illumination (CIE) in 1931. The color matching function of the RGB color system measured as tristimulus values (Red, Green, Blue). Is converted to a color matching function of the XYZ color system. In FIG. 11, the color matching functions indicating the characteristics of the original standard light are indicated by various solid lines as CIE (X), CIE (Y), and CIE (Z). In addition, color matching functions based on measurement values measured using a simple sensor such as a tristimulus value direct reading type are indicated by various broken lines as X, Y, and Z.

  As is clear from FIG. 11, the measured value of the simple sensor has a difference in characteristics as compared with the original color matching function, and the difference is particularly significant as a relative sensitivity deviation in the wavelength region surrounded by the one-dot chain line. Appears. In order to eliminate such a deviation, it is necessary to correct the measured value of the simple sensor to be close to the measured value of the reference measuring device according to the color matching function. As a correction method, a correction matrix M represented by the following formula 1 is used. In the correction matrix M of Equation 1, Xr, Yr, and Zr are values that represent measured values in the XYZ color system when a display screen displaying red (Red) monochromatic light is measured by a simple sensor. Similarly, Xg, Yg, and Zg are values related to green (Green), and Xb, Yb, and Zb are values related to blue (Blue). Further, Xref-r, Yref-r, and Zref-r are values obtained by measuring in the XYZ color system the measured value when a display screen displaying red monochromatic light is measured by the reference measuring device. Similarly, Xref-g, Yref-g, and Zref-g are values related to green, and Xref-b, Yref-b, and Zref-b are values related to blue.

  Such a correction matrix M is recorded in advance in a measuring apparatus using a simple sensor, for example. Then, the actual value obtained by measuring the display screen of the display device with the measuring device is corrected using the correction matrix M, and the display screen of the display device is adjusted based on the correction value of the actual value.

  For example, Patent Document 1 discloses a method of correcting the measurement value of the tristimulus value direct-reading sensor according to the measurement apparatus using a matrix.

JP 2007-093477 A

  However, the correction matrix is created by measuring a reference display device that displays a reference screen serving as a reference for display measurement. The reference display device is a display device having a standard or ideal display characteristic such as display intensity among the same model display devices, which is selected in advance at the development stage or manufacturing stage. Use. There are individual differences between individual display devices, and there are also individual differences between a commercially available display device obtained by a user and a reference display device. Such individual differences cannot be absorbed by a correction matrix created on the basis of the reference display device, and therefore there is a problem that sufficient correction to bring the measured value of the simple sensor close to the measured value of the reference measuring device cannot be expected.

  The present invention has been made in view of such circumstances, and not only the difference between the simple sensor and the reference measurement device, but also the individual difference between the reference display device and the display device to be measured is corrected. An object of the present invention is to provide a measurement system, a display device, a measurement device, a correction device, and a measurement method that can correct a measurement value with high accuracy.

  A measurement system according to the present invention includes a display device that displays an image on a display screen based on an input value, and a measurement device that measures the display intensity of the display screen of the display device. In the measurement system for measuring the display intensity, the display device or the measurement device includes a correction unit that corrects an actual measurement value, and the correction unit is a reference for displaying a display screen of a display device different from the display device in advance. Recording means for recording a first measurement value based on a result measured by the measurement device as a screen, and a second measurement value based on a result obtained by previously measuring the reference screen by a comparison measurement device different from the measurement device; An actual value acquisition means for acquiring an actual value of display intensity of the display screen obtained by measurement, and a correction value obtained by correcting the acquired actual value based on the first measurement value and the second measurement value. Characterized in that it comprises a correction value deriving means.

  In the present invention, the display on the display screen can be measured in consideration of the difference between the measuring device and the comparative measuring device and the difference between the reference screen and the display screen.

  In the measurement system according to the present invention, the correction value deriving unit derives a primary correction value based on a result obtained by dividing the acquired actual measurement value by the first measurement value, and the derived primary correction value is calculated as the first correction value. A secondary correction value is derived based on the result of multiplication by two measurement values, and the derived secondary correction value is used as the correction value.

  In the present invention, the display on the display screen can be measured in consideration of the difference between the measuring device and the comparative measuring device and the difference between the reference screen and the display screen.

  In the measurement system according to the present invention, the correction unit records the first measurement value and the second measurement value in the recording unit in association with a plurality of input values, respectively. Input value acquisition means for acquiring an input value, and reading means for reading the first measurement value and the second measurement value associated with the acquired input value from the recording means, the correction value deriving means, The correction value is derived based on the first measurement value and the second measurement value read by the reading means.

  In the present invention, measurement according to the input value can be performed.

  In the measurement system according to the present invention, the correction unit calculates a difference value between the theoretical value of the display intensity of the display screen displayed based on the input value and the first measurement value or the second measurement value on the recording unit. In the case where the first measurement value or the second measurement value corresponding to the input value acquired by the input value acquisition unit is not recorded in the recording unit, and is recorded in association with a plurality of input values in advance. Means for calculating an interpolated measurement value corresponding to the acquired input value from the first measurement value or the second measurement value recorded in the recording means, and an input value acquired from the difference value recorded in the recording means And means for calculating an alternative measurement value by adding the calculated interpolation difference value to the calculated interpolation measurement value. The correction value deriving means is read by the reading means. Instead of the first measured value or the second measured value Characterized in that you have to use a substitute measurements.

  In the present invention, in an interpolation process performed when a measurement value corresponding to the acquired input value is not recorded, an interpolation process using the interpolation measurement value and the interpolation difference value is performed.

  A display device according to the present invention includes a display screen that displays an image, and the display device that measures the display intensity of the display screen by a measurement device, the display intensity of the display screen obtained by the measurement of the measurement device. A first measurement based on a result of measurement by the measurement device using an actual measurement value acquisition unit for acquiring an actual measurement value, and using the acquired actual measurement value in advance as a reference screen serving as a display screen of a display device different from the device itself. And correction value deriving means for deriving a correction value corrected based on a value and a second measurement value based on a result obtained by measuring the reference screen in advance with a reference measurement device serving as a measurement reference.

  In the present invention, the display on the display screen can be measured in consideration of the difference between the measurement device and the reference measurement device and the difference between the reference screen and the display screen.

  The measuring device according to the present invention is a measuring device that measures the display intensity of a display screen included in a display device, an actual value acquisition unit that acquires an actual value of display intensity of the display screen obtained by measurement, and an acquired actual measurement A first measurement value based on a result obtained by measuring in advance a display screen of a display device different from the display device as a reference screen serving as a display reference, and a result obtained by measuring the reference screen in advance with another measurement device. Correction value deriving means for deriving a correction value corrected based on the second measurement value based thereon.

  In the present invention, not only the difference from the reference measurement apparatus but also the difference between the reference screen and the display screen can be taken into account to measure the display on the display screen.

  The correction device according to the present invention is a correction device that measures the display intensity of a display screen included in a display device with a measurement device and corrects an actual measurement value obtained by the measurement, and the display obtained by measurement of the measurement device. Actual measurement value acquisition means for acquiring an actual measurement value of the display intensity of the screen, and the acquired actual measurement value was measured in advance by the measurement device using a display screen of a display device different from the display device as a reference screen serving as a display reference A correction value deriving unit for deriving a correction value corrected based on a first measurement value based on the result and a second measurement value based on a result obtained by measuring the reference screen in advance with a reference measurement device serving as a measurement reference; It is characterized by that.

  In the present invention, the display on the display screen can be measured in consideration of the difference between the measurement device and the reference measurement device and the difference between the reference screen and the display screen.

  The measuring method according to the present invention is a measuring method for measuring the display intensity of the display screen of the display device with the measuring device, the measuring device measures the display intensity of the display screen, the measuring device or the display device, A first measurement value based on a result measured by the measurement device using a display screen of a display device different from the display device in advance as a reference screen serving as a reference for display, and a measurement for comparison different from the measurement device in advance. The second measurement value based on the result measured by the apparatus is recorded in advance, and the actual measurement value of the display intensity of the display screen by the measurement apparatus is corrected based on the first measurement value and the second measurement value. A correction value is derived.

  The measurement system, the display device, the measurement device, the correction device, and the measurement method according to the present invention are based on the difference between the measurement devices and the difference between the reference screen and the display screen. Measure the display on the display screen after correcting the above. As a result, it is possible to correct measured values that eliminate individual differences between individual display devices, and it is possible to accurately correct measured values of measuring devices to measured values according to color matching functions. There is an effect.

  In the present invention, since the first measurement value and the second measurement value are recorded in advance in association with the input value of the image, the measurement value can be corrected according to the input value. Even if a value is input to the display device, it is possible to perform highly accurate measurement.

  Furthermore, the present invention uses the interpolated measured value and the interpolated difference value when the measured value is recorded in association with the input value, and there is no measured value related to the corresponding input value and the interpolation process is performed. Perform interpolation processing. As a result, it is possible to realize a highly accurate measurement as compared with a case where only the measurement value is linearly interpolated.

In the measuring method which concerns on Embodiment 1 of this invention, it is a perspective view which shows the external appearance of an example of each apparatus used for the measurement of display intensity | strength. It is a block diagram which shows the structural example of the display apparatus and measuring apparatus which are used for the measuring method which concerns on Embodiment 1 of this invention. It is a functional block diagram which shows the structural example of the correction | amendment part with which the display apparatus used with the measuring method which concerns on Embodiment 1 of this invention is provided. It is a flowchart which shows an example of the measurement process of the display apparatus used with the measuring method which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows notionally correction of a measured value in the measuring method which concerns on Embodiment 1 of this invention. 5 is a graph conceptually showing correction of a measured value in the measurement method according to Embodiment 1 of the present invention. In the measurement method which concerns on Embodiment 1 of this invention, it is explanatory drawing which shows notionally an example of the recording content of the table which shows the relationship between an input value and the stimulus value of each color component. In the measuring method which concerns on Embodiment 1 of this invention, it is explanatory drawing which shows notionally an example of the recording content of the table which shows the relationship between an input value and the difference value of each color component. It is a flowchart which shows an example of the interpolation process of the display apparatus used with the measuring method which concerns on Embodiment 1 of this invention. It is a block diagram which shows the structural example of the display apparatus used for the measuring method which concerns on Embodiment 2 of this invention, and a measuring apparatus. It is a graph which shows the example of the error of the spectral response sensitivity of a measuring device.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof.

Embodiment 1 FIG.
FIG. 1 is a perspective view showing an external appearance of an example of each device used for measurement of display intensity in the measurement method according to Embodiment 1 of the present invention. In FIG. 1, reference numeral 1 denotes a display device such as a liquid crystal monitor. The display device 1 is a display device to be measured and includes a display unit 10 such as a liquid crystal panel. Displays an image based on input values such as the gradation value and amplitude of the image signal. The display device 1 is not limited to a liquid crystal monitor, and may be a device such as a CRT monitor, a PDP monitor, an organic EL display monitor, a projector, or electronic paper. The display device 1 is connected to a signal output device (not shown) such as a personal computer, a TV tuner, a DVD player, a game machine, various medical devices, and various machine tools. Output. The display device 1 and the signal output device may be integrated.

  The image displayed on the display screen 10 a of the display device 1 is measured by the measuring device 2. The measuring device 2 is connected to the display device 1 so as to be communicable by wired or wireless communication means. The measuring device 2 is a device that measures display intensity such as brightness of an image displayed on the display screen 10a, stimulus values, chromaticity, and density of RGB color components, and a sensor such as a tristimulus value direct reading sensor is used. .

  Next, a specific example for realizing the measurement method according to Embodiment 1 of the present invention will be described. FIG. 2 is a block diagram showing a configuration example of the display device 1 and the measurement device 2 used in the measurement method according to Embodiment 1 of the present invention.

  In addition to the display unit 10 described above, the display device 1 includes various mechanisms such as an input unit 11, an image processing unit 12, a reception unit 13, and a correction unit 14.

  The input unit 11 has a function of receiving an input of an image signal from the signal output device, and is configured by a mechanism such as a connector conforming to various communication standards and its attached circuit. The input unit 11 converts the image signal received from the signal output device into a signal that can be processed by the image processing unit 12, and outputs the converted image signal to the image processing unit 12.

  The image processing unit 12 is a mechanism such as an image controller that displays an image on the display unit 10 based on an image signal received from the input unit 11, a control unit 120 such as an MPU that controls the mechanism, and a flash that records various information. A recording unit 121 such as a memory is provided. The image signal received by the image processing unit 12 is an input value indicating a gradation value obtained by classifying each color component into, for example, 256 discrete values of 0 to 255 for each of a plurality of pixels constituting the image. By displaying pixels with luminance based on the gradation values on the display unit 10, the user can visually recognize a display image that is an aggregate of pixels. The classification number for the image signal is not limited to 256 levels, and may be lower or higher. 2 illustrates an image signal input from the outside of the display device 1 as an input value. However, the present invention is not limited to this, and an image signal is generated inside the display device 1 and the generated image signal is used as an input value. You may do it. Further, not only a digital value such as a gradation value but also an analog value such as an amplitude voltage value of a signal may be used as an input value. For example, state information such as brightness value, color temperature, and gradation characteristics indicating the state of an image set by the user is recorded in the recording unit 121, and the image processing unit 12 is recorded as a set value. The image quality of the image displayed on the display unit 10 is adjusted based on the information. Further, the image processing unit 12 adjusts the image displayed on the display screen 10 a of the display unit 10 based on the actual measurement value input from the correction unit 14 when displaying the image. As the image adjustment method based on the actual measurement value, various existing techniques such as the use of LUT (Look Up Table) based on various γ curves recorded in advance in the recording unit 121 are applied. Note that the actual measurement value input from the correction unit 14 is not the actual measurement value itself obtained by the measurement of the measuring device 2 but the actual measurement value corrected by the correction unit 14 by a method described later. Further, the image processing unit 12 outputs the input value such as the gradation value included in the image signal received from the input unit 11 and the state information recorded in the recording unit 121 to the correction unit 14.

  The receiving unit 13 has a function of receiving an actual measurement value transmitted from the measuring device 2, and is configured by a mechanism such as a connector conforming to various communication standards and its attached circuit. The receiving unit 13 converts the actual measurement value received from the measurement apparatus 2 into a signal that can be processed by the correction unit 14, and outputs the converted actual measurement value to the correction unit 14.

  The correction unit 14 is a mechanism such as a microcomputer that corrects the actual measurement value received from the measurement apparatus 2 and outputs the corrected actual measurement value to the image processing unit 12, and includes a control unit 140 such as an MPU that controls the entire mechanism, and various types. A recording unit 141 such as a flash memory for recording information is provided. The correction unit 14 is manufactured as an embedded circuit of the display device 1, but may be manufactured as an optional device that can be separately incorporated into the existing display device 1. The correction unit 14 receives an input of the input value and the state information from the image processing unit 12 and functions as a correction device that corrects the measurement value under the control of the control unit 140 based on the input value and the state information. A specific example of processing will be described later.

  The measuring device 2 includes various mechanisms such as a detection unit 20, a color value calculation unit 21, and a transmission unit 22.

  The detection unit 20 is a mechanism that uses a sensor as a light receiving element such as a CCD that detects display intensity such as luminance of an image displayed on the display screen 10a of the display device 1, stimulus values, chromaticity, and density of each color component. The display intensity is output to the color value calculator 21 as a count value for each wavelength.

  The colorimetric value calculation unit 21 is a calculation circuit that converts the count value for each wavelength input from the detection unit 20 into a display intensity that can be processed as an actual measurement value by performing calculation such as integration. The actually measured value (display intensity) is passed to the transmitter 22.

  The transmission unit 22 is configured by a mechanism such as a connector conforming to various communication standards and its attached circuit. The transmission unit 22 converts the actual measurement value received from the color value calculation unit 21 into a communication signal and transmits the communication signal to the display device 1.

  FIG. 3 is a functional block diagram showing a configuration example of the correction unit 14 included in the display device 1 used in the measurement method according to Embodiment 1 of the present invention. Under the control of the control unit 140 based on various information recorded in the recording unit 141, the correction unit 14 is a measured value acquisition unit 14a, an input value acquisition unit 14b, a state information acquisition unit 14c, a standard measurement value derivation unit 14d, a reference It functions as the measurement value deriving unit 14e, the primary correction value deriving unit 14f, and the secondary correction value deriving unit 14g.

  The actual measurement value acquisition unit 14a has a function of acquiring the display intensity received from the measurement device 2 as an actual measurement value.

  The input value acquisition unit 14b has a function of acquiring an input value such as a gradation value related to an image displayed on the display screen 10a.

  The state information acquisition unit 14c has a function of acquiring state information such as a brightness value indicating the state of an image, a color temperature, and gradation characteristics.

  The standard measurement value deriving unit 14d has a function of deriving a standard measurement value (first measurement value) used for correcting the actual measurement value. The standard measurement value is a measurement value based on a result obtained by measuring a reference screen serving as a display reference in advance using a measurement apparatus. As the measurement device used for measuring the reference screen, it is desirable to use the measurement device 2 that actually measures the display intensity in the present embodiment, but has the same or similar measurement characteristics as the measurement device 2. It is possible to use another measuring device capable of measuring that can be regarded as equivalent to the measurement by the measuring device 2. The reference screen serving as a display reference is a display screen of a display device (standard display device) different from the display device 1 but having the same specifications selected for use in adjustments such as device calibration. Since the display intensity of the reference screen varies depending on the input value and the state information, the standard measurement value for each input value and state information is recorded in the recording unit 141 in advance as a first table TBL1 in a format such as LUT. The standard display device is selected from the group of display devices having the same specifications as the display device 1 and has a standard or ideal display characteristic such as display intensity at the development stage or the manufacturing stage.

  The standard measurement value deriving unit 14d refers to the first table TBL1 based on the input value and the state information, and derives a standard measurement value corresponding to the input value and the state information. If the gradation values classified into 256 gradations from 0 to 255 are used for the RGB components as the input values, there are 256 cubed input values, and status information for each input value. If each standard measurement value is recorded, the amount of information becomes enormous. Therefore, the standard measurement values corresponding to all the input values and the state information are not recorded in the first table TBL1, but only the standard measurement values corresponding to a specific input value or the like are recorded. And about the standard measurement value corresponding to the input value etc. which are not recorded, a standard measurement value is derived | led-out by the interpolation process mentioned later.

  The reference measurement value deriving unit 14e has a function of deriving a reference measurement value (second measurement value) used for correcting the actual measurement value. The reference measurement value is a measurement value based on a result obtained by measuring the above-described reference screen in advance using a reference measurement device (comparison measurement device) serving as a measurement reference. The reference measurement device is a measurement device having a function as a measurement reference sensor. For example, a spectroscopic color measurement device having higher measurement accuracy and higher performance than the measurement device 2 is used. Further, the reference value for each input value and state information is recorded in advance in the recording unit 141 as the second table TBL2 in a format such as LUT.

  The reference measurement value deriving unit 14e refers to the second table TBL2 based on the input value and the state information, and derives a reference measurement value corresponding to the input value and the state information. In the second table TBL2, not only the reference measurement values corresponding to all the input values and the state information are recorded, but only the reference measurement values corresponding to a specific input value or the like are recorded, and if necessary, Thus, a reference measurement value is derived by interpolation processing described later. For convenience of explanation, the first table TBL1 and the second table TBL2 are shown as different tables, but are configured as one table that records standard measurement values and reference measurement values in association with input values and state information. Anyway.

  The primary correction value deriving unit 14f functions as a divider for deriving the primary correction value by dividing the actual measurement value acquired by the actual measurement value acquiring unit 14a by the standard measurement value derived by the standard measurement value deriving unit 14d. Have.

  The secondary correction value deriving unit 14g multiplies the primary correction value derived by the primary correction value deriving unit 14f by the secondary correction value derived by the reference correction value deriving unit 14e to derive a secondary correction value. It functions as a vessel.

  The correction unit 14 outputs the secondary correction value derived by the secondary correction value deriving unit 14g to the image processing unit 12 as a corrected measurement value.

  In FIG. 3, the configuration example of the correction unit 14 is conceptually illustrated as a functional block diagram, but even if configured as a program executed by the control of the control unit 140, a part or all of the program is a chip such as a VLSI. It may be configured as hardware built in.

  The procedure of dividing the actual measurement value by the standard measurement value and then multiplying by the reference measurement value is merely an example. That is, after multiplying by the standard correction value, it may be divided by the standard measurement value, or the quotient obtained by dividing the standard correction value by the standard measurement value may be multiplied by the actual measurement value. Furthermore, not only multiplication and division, but other calculations such as addition and subtraction may be used to correct the actual measurement values based on the standard measurement value and the reference measurement value. And you may make it perform the tertiary correction | amendment which fine-tunes a calculation result as needed.

  Next, the measurement process of the display device 1 will be described. FIG. 4 is a flowchart showing an example of measurement processing of the display device 1 used in the measurement method according to Embodiment 1 of the present invention. The flowchart shown in FIG. 4 shows the measurement process of the display device 1 with a focus on the process of the correction unit 14. The display device 1 displays an image based on the input value on the display screen 10a of the display unit 10 according to the set state information. Then, the display intensity of the display screen is measured by the measuring device 2, and the measuring device 2 transmits the actual measurement value obtained by the measurement to the display device 1.

  The correction unit 14 uses the various types of information recorded in the recording unit 141 and executes the following processing under the control of the control unit 140. The correction unit 14 acquires the actual measurement value received by the display device 1 from the measurement device 2 by the actual measurement value acquisition unit 14 (S101).

  Further, the correction unit 14 acquires an input value by the input value acquisition unit 14b (S102), and acquires state information by the state information acquisition unit 14c (S103).

  Next, the correction unit 14 extracts a standard measurement value group from the first table TBL1 corresponding to the acquired state information by the standard measurement value deriving unit 14d (S104), and acquires the acquired input from the extracted standard measurement value group. A standard measurement value corresponding to the value is derived (S105). The process of step S104 indicates a process of extracting a plurality of standard measurement values corresponding to the acquired state information from the first table TBL1 in which standard measurement values are recorded in association with the state information and input values. For example, when a plurality of first tables TBL1 in which input values and standard measurement values are associated are recorded for each state information, the first table TBL1 corresponding to the acquired state information is extracted. The process of step S105 indicates a process of deriving a standard measurement value corresponding to the acquired input value from the standard measurement value group for which the state information is determined. In deriving the standard measurement value corresponding to the input value, interpolation processing is performed as necessary.

  The correction unit 14 extracts the reference measurement value group from the second table TBL2 corresponding to the acquired state information by the reference measurement value deriving unit 14e (S106), and corresponds to the acquired input value from the extracted reference measurement value group. A reference measurement value is derived (S107). The process of step S106 indicates a process of extracting a plurality of reference measurement values corresponding to the acquired state information from the second table TBL2 in which the reference measurement values are recorded in association with the state information and input values. For example, when a plurality of second tables TBL2 in which input values and standard measurement values are associated are recorded for each state information, the second table TBL2 corresponding to the acquired state information is extracted. The process of step S107 indicates a process of deriving a reference measurement value corresponding to the acquired input value from the reference measurement value group whose state information has been determined. In deriving the reference measurement value corresponding to the input value, interpolation processing is performed as necessary.

  Next, the correction unit 14 derives a primary correction value by dividing the actual measurement value of the display intensity acquired by the actual measurement value acquisition unit 14a by the standard measurement value by the primary correction value deriving unit 14f (S108).

  Next, the correction unit 14 derives a secondary correction value by multiplying the primary correction value by the reference measurement value by the secondary correction value deriving unit 14g (S109).

  The correction unit 14 outputs the derived secondary correction value to the image processing unit 12 as a corrected measurement value. Then, the display device 1 adjusts the display on the display screen based on the secondary correction value by the processing of the image processing unit 12 (S110). In this way, the adjustment process is executed. For convenience of explanation, it is described that the processes of steps S101 to S110 are performed in order. For example, the processes of steps S101 to S103 are performed in parallel, and the processes of S104 and S106 are performed in parallel. It is possible to design appropriately. Although the display screen display is adjusted in step S110, the present invention is not limited to this, and the measurement value corrected in step S109 may be displayed on the display screen of the display device 1 to notify the user. In addition, the measurement value corrected in step S109 may be stored in the display device 1, the measurement device 2, or another device.

  Next, the correction of the measurement value according to the measurement method of the present invention will be conceptually described. FIG. 5 is an explanatory diagram conceptually showing correction of a measured value in the measurement method according to Embodiment 1 of the present invention. The table in the center of FIG. 5 shown as A shows the relationship between the input value and the measured value. The column in the center of the table shows the gradation values classified into 256 levels from 0 to 255 as the input values, and the measured values of the image displayed on the display screen based on the input values in the columns on both sides of the input values. Is shown in the XYZ color system. The left side of the input value indicates a reference measurement value obtained by measuring the reference screen using a reference measurement device. For example, an image having an input value of 128 is displayed on a standard display device, and a result of measuring the displayed image using a reference measurement device is (X128, Y128, Z128) using an XYZ color system. Become. The right side of the input value indicates a standard measurement value that is displayed on a standard display device and the displayed image is measured using the measurement device 2. For example, an image having an input value of 128 is displayed on a standard display device, and a result of measuring the displayed image using the measuring device 2 is obtained using the XYZ color system (X′128, Y′128). , Z′128).

  The graph on the upper left side in FIG. 5 shown as B shows the reference measurement value measured on the reference screen using the reference measurement device on the XYZ color axis indicating the XYZ color system and connected by a solid line.

  The lower right graph in FIG. 5 shown as C shows the standard measurement value measured on the reference screen using the measuring device 2 on the XYZ axis indicating the XYZ color system and connected by a solid line. . Further, the display screen 10a is displayed with the same input value on the display device 1 to be measured, and the measurement value measured using the measurement device 2 is indicated by a broken line. That is, the difference between the solid line and the broken line in the graph C indicates the variation due to the individual difference of the display device 1 based on the measurement result of the measurement device 2.

  A graph on the lower left side in FIG. 5 shown as D shows a measurement value obtained by measuring the display screen 10a of the display device 1 to be measured using the reference measurement device on the XYZ axis indicating the XYZ color system. It is shown and connected with a solid line. Moreover, the broken line has shown the reference | standard measured value which measured the display screen 10a using the reference | standard measuring apparatus, and is the same as the continuous line shown in the graph B. FIG. That is, the difference between the solid line and the broken line in the graph D indicates the variation due to the individual difference of the display device 1 based on the measurement result of the reference measurement device. The measurement value indicated by the solid line in the graph D is the measurement value originally desired to be obtained according to the color matching function, but it is difficult for the user to obtain an expensive reference measurement device. In the present invention, the change due to the individual difference of the display device 1 obtained by the inexpensive measurement device 2 shown in the graph C is used to correct the reference measurement value shown by the broken line in the graph D, thereby indicating the solid line in the graph D. The measured value was obtained.

  FIG. 6 is a graph conceptually showing correction of measured values in the measurement method according to Embodiment 1 of the present invention. In each graph, the horizontal axis represents the input value indicated by the gradation value, and the vertical axis represents the luminance value as the display intensity, indicating the measurement characteristics of each measuring device.

The graph shown as A on the upper left side in FIG. 6 shows the characteristics when the reference screen displayed on the standard display device is measured. The thick line shows the measurement characteristics of the reference measurement device, and the thin line shows the measurement. The measurement characteristics of the device are shown. As shown in the graph A, since the measurement characteristics of the reference measurement device and the measurement device are different, the curves indicating the relationship between the gradation value and the luminance value do not match. For example, when the gradation value is 255, the luminance value measured by the reference measuring device is 300 [cd / m ² ], whereas the luminance value measured by the measuring device is 250 [cd / m ² ].

  In the graph shown as B on the right side in FIG. 6, the curve indicated by the solid line is a characteristic when the reference screen is measured by the reference measurement device, and the curve indicated by the broken line is the display of the display device 1 to be measured. Although the screen is a measurement value originally intended to be obtained by measurement, the measurement requires a reference measurement device, and it is difficult for the user to obtain an expensive reference measurement device as described above.

  In the graph shown as C on the lower left side in FIG. 6, the curve indicated by the dotted line is a characteristic when the display screen 10 a of the display device 1 to be measured is measured by the measuring device 2. A curve indicated by a solid line indicates characteristics when the reference screen displayed on the standard display device is measured by the measurement apparatus, and is the same curve as the curve indicated by the thin line in the graph A.

  As shown in the graph B and the graph C, regarding the measurement of the display screen displayed when the gradation value is 255, the measurement value measured on the reference screen and the measurement measured on the display screen 10a are 0.88. A rate of change has occurred. In the measurement method according to the present invention, the change rate of 0.88 is regarded as the individual difference of the display device 1 with respect to the display device, and the measured value by the reference measurement device for the display image in the case of the input gradation 255, ie, the graph B By multiplying 300 [cd / m 2] on the curve shown as a solid line by the rate of change 0.88, it is possible to obtain a value 264 [cd / m 2] that should be measured.

  Next, the interpolation process of the display device 1 will be described. As described above, in the measurement method according to the present invention, the reference measurement value and the standard measurement value are recorded for each state information and each input value, so that the recording unit 121 having a large recording capacity is required. Therefore, as a method for reducing the recording capacity, the recording capacity is reduced not by recording each input value but by recording only the reference measurement value and the standard measurement value corresponding to the specific input value. And, for reference measurement values and standard measurement values corresponding to unrecorded input values, it can be handled by performing interpolation processing based on reference measurement values and standard measurement values corresponding to a plurality of recorded input values. A process of substituting a reference measurement value and a standard measurement value to be performed is performed. However, since the display characteristic of the display device to be measured is a power function γ curve, sufficient accuracy cannot be expected by general linear interpolation. Therefore, in the measurement method of the present invention, high-precision interpolation processing is realized by using the difference between the theoretical value and the measured value instead of the measured value.

  FIG. 7 is an explanatory diagram conceptually showing an example of the recorded contents of a table showing the relationship between the input value and the stimulus value of each color component in the measurement method according to Embodiment 1 of the present invention. FIG. 7 is an example of a table used as the first table TBL1 or the second table TBL2, and shows standard measurement values or reference measurement values with respect to input values as stimulus values of RGB color components. In addition, on the assumption that the stimulus value of each color component is converted into the XYZ color system and then processed by the image processing unit 12, an example of performing conversion to the XYZ color system using the table is shown. Yes. Further, the table shown in FIG. 7 performs substantially the same processing when used for derivation with respect to any of the standard measurement values recorded in the first table TBL1 and the reference measurement values recorded in the second table TBL2. In the following description, the measurement values are shown as a recorded table.

  The input value is acquired as a gradation value classified into 256 levels from 0 to 255, but the stimulation values corresponding to all the input values are not recorded, but 0, 8, 16,. Only stimulus values corresponding to specific input values are recorded.

  FIG. 8 is an explanatory diagram conceptually showing an example of the recorded contents of a table showing the relationship between the input value and the difference value of each color component in the measurement method according to Embodiment 1 of the present invention. FIG. 8 is an example of tables used as the first table TBL1 and the second table TBL2. When performing the interpolation processing according to the present invention, as the first table TBL1 and the second table TBL2, together with the table showing the relationship between the input value and the stimulus value shown in FIG. 7, the input value and the difference value shown in FIG. A table showing the relationship is provided. For convenience of explanation, in the following explanation, the table shown in FIG. 7 is shown as a measurement value table, and the table shown in FIG. 8 is shown as a difference value table. The measurement value table and the difference value table can be configured as one data file associated with the input value, and can be used as the first table TBL1 and the second table TBL2.

  The difference value recorded in the difference value table indicates the difference between the measured value measured in advance and the theoretical value of the display intensity of the image displayed on the screen based on the input value. In the difference value table shown in FIG. 8, the difference value with respect to the input value is shown as the stimulus value of each RGB color component. Note that the stimulus value of each color component is added to the stimulus value converted into the XYZ color system using the measurement value table and then processed by the image processing unit 12 according to the table. An example of performing conversion to a color system is also shown. When the difference value table is applied to the first table TBL1, the difference value related to the theoretical value of the display intensity of the reference screen displayed on the standard display device is used, and when the difference value table is applied to the second table TBL2, The difference value related to the theoretical value of the display intensity of the display screen displayed on the measuring device is used. As described above, since the measurement value is a power function curve, it is not possible to expect sufficient accuracy when performing linear interpolation. However, since the difference between the theoretical value and the measured value changes in a linear function, in the present invention, linear interpolation is performed with the difference value, and this is added to the theoretical value so that the accuracy is not impaired. Is realized.

  The input value is acquired as a gradation value classified into 256 levels from 0 to 255, but the differential values corresponding to all the input values are not recorded, but 0, 8, 16,. Only the difference value corresponding to a specific input value is recorded.

  Next, specific processing contents of the interpolation processing performed using the measurement value table and the difference value table will be described. FIG. 9 is a flowchart showing an example of interpolation processing of the display device 1 used in the measurement method according to Embodiment 1 of the present invention. The flowchart shown in FIG. 9 shows the interpolation processing of the display device 1 centering on the processing of the correction unit 14.

  The correction unit 14 uses the various types of information recorded in the recording unit 141, and as a process for deriving the standard measurement value in step S105 of the adjustment process shown in FIG. Perform interpolation processing. The correcting unit 14 determines whether or not the measurement value associated with the acquired input value is recorded in the measurement value table of the first table TBL1 (S201).

  If it is determined in step S201 that the data is recorded (S201: YES), the correction unit 14 extracts a measurement value associated with the acquired input value from the measurement value table of the first table TBL1. A standard measurement value in step S105 is derived. If necessary, a difference value associated with the acquired input value is extracted from the difference value table of the first table TBL1, and the extracted difference value is added to the measurement value extracted from the measurement value table. The standard measurement value may be used. And the process after step S106 of an adjustment process is performed.

  In step S201, when it is determined that no data is recorded (S201: NO), the correction unit 14 calculates an interpolated measurement value from a plurality of measurement values recorded in the measurement value table of the first table TBL1 (S202). . In step S202, each measurement value associated with a plurality of input values recorded in the measurement value table is extracted, and an interpolation measurement value is calculated by performing linear interpolation based on the extracted measurement value. For example, when the acquired input value is 10, the stimulus value associated with the input value 8 and the stimulus value associated with the input value 16 are extracted, and linear interpolation processing is performed, thereby performing interpolation measurement. Calculate the value. The calculation of the interpolation measurement value is performed for each color component.

  Further, the correction unit 14 calculates an interpolation difference value from a plurality of difference values recorded in the difference value table of the first table TBL1 (S203). In step S203, each measurement value associated with a plurality of input values recorded in the difference value table is extracted, and an interpolation difference value is calculated by performing linear interpolation based on the extracted measurement value. For example, when the acquired input value is 10, the difference value associated with the input value 8 and the difference value associated with the input value 16 are extracted, and the interpolation difference value is obtained by performing linear interpolation processing. Is calculated. The interpolation difference value is calculated for each color component.

  Then, the correction unit 14 calculates an alternative measurement value by adding the calculated interpolation difference value to the calculated interpolation measurement value (S204). The alternative measurement value calculated in step S204 is used as an alternative value for the standard measurement value in step S105. That is, the standard measurement value is derived by the processing in steps S202 to S204.

  The correction unit 14 uses the measurement value table and the interpolation value table of the second table TBL2 by performing the same interpolation process in the derivation of the reference measurement value in step S107 of the adjustment process shown in FIG. The reference measurement value is derived. In this way, the interpolation process is executed. In the linear interpolation process, various calculation methods for improving accuracy, such as calculation using three or more values, can be applied. It has been experimentally found that by performing such an interpolation process, it is possible to derive a value with higher accuracy than the conventional linear interpolation process. In addition, the interpolation processing shown in the present application can be applied to interpolation processing for the purpose of reducing recorded contents and improving accuracy even in methods other than the measurement method of the present application.

  In the first embodiment, the form using the table indicating the relationship between the input value and the stimulus value of each color component has been described. However, the present invention is not limited to this. For example, the form in which the theoretical value is calculated each time, etc. It can be developed in various forms. And in the form which calculates a theoretical value each time, the theoretical measured value corresponding to the input value determined not to be recorded is calculated in the step S202, and the calculated theoretical measured value is calculated in the step S204. This can be realized by adding the interpolated difference value and measuring the alternative measurement value. By doing so, the table showing the relationship between the input value and the stimulus value of each color component shown in FIG. 7 becomes unnecessary, and it becomes possible to execute interpolation processing with a simpler circuit.

  As described above, the measurement method according to Embodiment 1 of the present application can be realized.

Embodiment 2. FIG.
The second embodiment is a mode in which the correction unit in the first embodiment is provided not in the display device side but in the measurement device. In the following description, components similar to those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and detailed description thereof is omitted.

  FIG. 10 is a block diagram showing a configuration example of the display device 1 and the measurement device 2 used in the measurement method according to Embodiment 2 of the present invention.

  The display device 1 includes various mechanisms such as a display unit 10, an input unit 11, an image processing unit 12, a reception unit 13, and a transmission unit 15.

  The receiving unit 13 has a function of receiving a measurement value transmitted from the measuring device 2, and is configured by a mechanism such as a connector conforming to various communication standards and its attached circuit. Note that the measured value received by the receiving unit 13 in the second embodiment is a measured value obtained by correcting the optical value actually measured by the measuring apparatus 2, that is, the actually measured value corrected in the first embodiment.

  The transmission unit 15 has a function of transmitting input values and state information to the measuring device 2, and is configured by a mechanism such as a connector conforming to various communication standards and its attached circuit. In FIG. 10, the receiving unit 13 and the transmitting unit 15 are illustrated as different mechanisms. However, when the communication unit conforms to a communication standard capable of bidirectional communication, the receiving unit 13 and the transmitting unit 15 are formed as an integrated mechanism. You may make it do.

  The measuring device 2 includes various mechanisms such as a detection unit 20, a colorimetric value calculation unit 21, a transmission unit 22, a reception unit 23, a correction unit 24, and the like.

  The transmission unit 22 transmits the actual measurement value corrected by the correction unit 24 to the display device 1.

  The receiving unit 23 is configured by a mechanism such as a connector conforming to various communication standards and its attached circuit. The receiving unit 23 receives input values and state information from the display device 1. In FIG. 10, the transmission unit 22 and the reception unit 23 are shown as different mechanisms. However, if the communication unit conforms to a communication standard capable of bidirectional communication, the transmission unit 22 and the reception unit 23 are formed as an integrated mechanism. You may make it do.

  The correction unit 24 is a mechanism such as a microcomputer that corrects the actual measurement value output from the colorimetric value calculation unit 21 and outputs the corrected actual measurement value to the transmission unit 22 so as to be transmitted to the display device 1. A control unit 240 such as an MPU for control and a recording unit 241 such as a flash memory for recording various information are provided. The correction unit 24 is manufactured as an embedded circuit of the measurement device 2, but may be manufactured as an optional device that can be separately incorporated into an existing measurement device. The correction unit 24 functions as a correction device that receives an input of the input value and the state information from the display device 1 via the reception unit 23, and corrects the measurement value under the control of the control unit 240 based on the input value and the state information. .

  The specific processing of the correction unit 24 is substantially the same as that of the correction unit 14 included in the display device 1 described in the first embodiment.

  In the display device 1 and the measurement device 2 according to the second embodiment configured as described above, the input value and the state information are transmitted from the display device 1 to the measurement device 2. In the measurement apparatus 2, the actual measurement value obtained by the measurement is corrected based on the input value and the state information by the processing of the correction unit 24, and the corrected actual measurement value is transmitted to the display apparatus 1. In the display device 1, an image is displayed on the display unit 10 by the image processing unit 12 based on the actually measured value that has been corrected. Further, the interpolation processing shown in the first embodiment is performed as necessary.

  As described above, the measurement method according to Embodiment 2 of the present application can be realized.

  The forms shown in the first and second embodiments are only a part of the innumerable examples of the present application, and are based on the results of measuring the reference screen displayed on the standard display device with the reference measurement device and the measurement device. Thus, the present invention can be applied to various forms in which processing such as image adjustment is performed after correcting an actual measurement value obtained by measuring an image to be measured.

  For example, in the first embodiment, the correction unit is incorporated in the display device, and in the second embodiment, the correction unit is incorporated in the measurement device. However, the present invention is not limited thereto, and an apparatus including the correction unit is provided. You may make it provide as an apparatus different from a display apparatus and a measuring apparatus.

  In addition, various forms can be applied to the actual value conversion method, such as converting each stimulus value of the RGB component into an XYZ coordinate system value using a correction matrix instead of a table.

DESCRIPTION OF SYMBOLS 1 Display apparatus 10 Display part 10a Display screen 11 Input part 12 Image processing part 120 Control part 121 Recording part 13 Receiving part 14 Correction part 140 Control part 141 Recording part 14a Actual value acquisition means 14b Input value acquisition means 14c Status information acquisition means 14d Standard measurement value derivation means 14e Reference measurement value derivation means 14f Primary correction value derivation means 14g Secondary correction value derivation means 15 Transmitter 2 Measuring device 20 Detection section 21 Colorimetric value calculation section 22 Transmission section 23 Reception section 24 Correction section 240 Control Section 241 Recording section

Claims (8)

In a measurement system comprising: a display device that displays an image on a display screen based on an input value; and a measurement device that measures the display intensity of the display screen of the display device, and the display device measures the display intensity of the display screen. ,
The display device or measuring device is
A correction unit that corrects the actual measurement value
The correction unit
A first measurement value based on a result of measurement performed by the measurement device using a display screen of a display device different from the display device in advance as a reference screen serving as a display reference; Recording means for recording a second measurement value based on the result of measurement at
Actual value acquisition means for acquiring an actual value of display intensity of the display screen obtained by measurement,
And a correction value deriving means for deriving a correction value obtained by correcting the acquired actual measurement value based on the first measurement value and the second measurement value. The correction value deriving means includes
Based on the result obtained by dividing the acquired actual measurement value by the first measurement value, a primary correction value is derived,
A secondary correction value is derived based on a result obtained by multiplying the derived primary correction value by the second measurement value;
The measurement system according to claim 1, wherein the derived secondary correction value is used as the correction value. The correction unit is
The first measurement value and the second measurement value are recorded in the recording means in association with a plurality of input values, respectively.
Furthermore,
Input value acquisition means for acquiring an input value of the display device;
Reading means for reading the first measurement value and the second measurement value associated with the acquired input value from the recording means;
3. The correction value deriving unit is configured to derive a correction value based on the first measurement value and the second measurement value read by the reading unit. 4. Measuring system. The correction unit is
In the recording means, a difference value between the theoretical value of the display intensity of the display screen displayed based on the input value and the first measurement value or the second measurement value is recorded in association with a plurality of input values in advance. Yes,
When the first measurement value or the second measurement value corresponding to the input value acquired by the input value acquisition unit is not recorded in the recording unit,
Means for calculating an interpolated measurement value corresponding to the acquired input value from the first measurement value or the second measurement value recorded in the recording means;
Means for calculating an interpolation difference value corresponding to the acquired input value from the difference value recorded in the recording means;
Means for calculating an alternative measurement value by adding the calculated interpolation difference value to the calculated interpolation measurement value,
The measurement system according to claim 3, wherein the correction value deriving unit uses an alternative measurement value instead of the first measurement value or the second measurement value to be read by the reading unit. In a display device comprising a display screen for displaying an image, and measuring the display intensity of the display screen by a measuring device,
Actual value acquisition means for acquiring an actual value of display intensity of the display screen obtained by measurement of the measurement device;
The acquired actual measurement value is a first measurement value based on a result measured by the measurement device using a display screen of a display device different from its own device as a reference screen as a display reference, and a reference for measuring the reference screen in advance. And a correction value deriving means for deriving a correction value corrected based on the second measurement value based on the result measured by the reference measurement device. In the measuring device for measuring the display intensity of the display screen provided in the display device,
Actual value acquisition means for acquiring an actual value of display intensity of the display screen obtained by measurement,
A first measurement value based on a result obtained by measuring an acquired actual measurement value in advance using a display screen of a display device different from the display device as a reference screen as a display reference, and the reference screen is previously measured by another measurement device. And a correction value deriving unit for deriving a correction value corrected based on the second measurement value based on the result. In the correction device for measuring the display intensity of the display screen provided in the display device with a measurement device, and correcting the actual value obtained by the measurement,
Actual value acquisition means for acquiring an actual value of display intensity of the display screen obtained by measurement of the measurement device;
The first measurement value based on the measurement result obtained by the measurement device using the display screen of the display device different from the display device as a reference screen as a display reference, and the reference screen measured in advance. A correction apparatus comprising: a correction value deriving unit that derives a correction value corrected based on a second measurement value based on a result measured by a reference measurement apparatus serving as a reference. In the measuring method of measuring the display intensity of the display screen of the display device with a measuring device,
The measuring device is
Measure the display intensity of the display screen,
The measuring device or display device is
A first measurement value based on a result measured by the measurement device using a display screen of a display device different from the display device in advance as a reference screen serving as a reference for display, and a measurement for comparison different from the measurement device in advance. The second measurement value based on the result measured by the device is recorded in advance,
A measurement method characterized by deriving a correction value obtained by correcting an actual measurement value of the display intensity of the display screen by the measurement device based on the first measurement value and the second measurement value.

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