A method for measuring the radiation of a display light field

Abstract

This invention provides a method for measuring the radiation of a display field, enabling the measurement of hyperspectral information of a display screen under test. Specifically, the method includes: S1: controlling the display screen under test to display a first set of images, and using the spectral measurement device to obtain the spectral power distribution of region A of the display screen under test under the corresponding image; S2: selecting two or more specific filters based on the spectral power distribution of region A obtained in step S1; S3: controlling the display screen under test to display a second set of images, sequentially inserting the filters selected in step S2 into the optical path, and the light from region B of the display screen under test being received by an area array sensor through an imaging lens and the filters; S4: calculating the spectral power distribution of each position point in region B of the display screen under test when displaying the second set of images, based on the pixel response value of the area array sensor in step S3 and the spectral power distribution of region A of the display screen under test in step S1.

Description

Technical Field

[0001] This invention relates to the field of optoelectronic testing, and more specifically to a method for measuring the radiation of a display light field. Background Technology

[0002] In today's rapidly developing display technology, the rapid and accurate measurement of fundamental optical parameters such as brightness and chromaticity is crucial for display screen research, development, production, and quality control. Display screen brightness and chromaticity are generally measured using point-type or image-type luminance meters. Point-type luminance meters can only measure the brightness and chromaticity of one point at a time, resulting in low efficiency when measuring the entire two-dimensional plane and requiring significant time to evaluate display screen uniformity. Image-type luminance meters, on the other hand, have a two-dimensional area array sensor with a filter in front of it that matches the response to the human eye's visual function, enabling rapid acquisition of the brightness of each point within the two-dimensional plane of the display screen in a single imaging measurement. However, the spectral matching degree of image-type luminance meters is generally lower than that of high-precision filter-type point-type luminance meters. The matching degree between the filter group of image-type luminance meters and the human eye's chromaticity function is generally poor, leading to significant errors in the measured brightness and chromaticity parameters. Although the spectral power distribution of a small area can be measured by a point-type luminance meter to calibrate an image-type luminance meter, the spectrum measured by the spectrometer in this method cannot correspond to each pixel in the image luminance meter. Furthermore, the brightness and color of the display screen are often non-uniform, so the correction coefficient for this small area cannot be applied to the brightness and color correction of the entire display screen area.

[0003] In recent years, hyperspectral image luminance meters have emerged in the market for measuring the light and color of displays. They use a large number of narrowband filters to obtain hyperspectral images, thereby calculating the luminance and chromaticity of each point on the display screen. However, due to the large number of narrowband filters required, the measurement speed is slow and cannot meet the needs for rapid measurement in the research, development, production, and quality control of displays. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method for measuring the radiation of a display light field, aiming to achieve rapid and accurate measurement of the brightness, chromaticity, and uniformity of a display screen.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] This invention provides a method for measuring the radiation of a display light field. Utilizing a spectral measurement device, a filter, and an imaging measurement device including an area array sensor, the method measures the hyperspectral information of the display screen under test. Specifically, it includes the following steps:

[0007] S1: Control the display screen under test to display the first set of images, and use the spectral measurement device to obtain the spectral power distribution of region A of the display screen under test under the corresponding image;

[0008] S2: Based on the spectral power distribution of region A obtained in step S1, select two or more specific filters;

[0009] S3: Control the display screen under test to display the second set of images, and sequentially insert the filters selected in step S2 into the optical path. The light from area B of the display screen under test is received by the area array sensor through the imaging lens and the filters. Each position point in area B of the display screen under test corresponds to a specific pixel point of the area array sensor.

[0010] S4: Based on the pixel response value of the area array sensor in step S3 and the spectral power distribution of area A of the display screen under test in step S1, calculate the spectral power distribution of each position point in area B when the display screen under test displays the second set of images.

[0011] It should be noted that in the above technical solution, region B can be the entire light-emitting area of ​​the display screen under test, and region A can be a designated light-emitting area on the display screen under test, with region A located within region B. Figure 1 As shown. A specific pixel or set of pixels on the area array sensor corresponds to region A. The hyperspectral information of the display screen under test refers to the spectral power distribution data of various locations in region B. The first set of images and the second set of images can each be a single image, or they can each be two or more sets of images. The filter selected in step S2 is generally a bandpass filter.

[0012] In the above technical solution, after obtaining the spectral power distribution of the display screen under test A area under the corresponding screen using the spectral measurement device, the peak wavelengths of each primary color of the display screen under test are obtained according to the spectral power distribution of the A area. The selected two or more bandpass filters cover the peak wavelengths of each primary color of the display screen under test measured in step S1.

[0013] Furthermore, each primary color of the display screen under test corresponds to at least one bandpass filter, and the number of bandpass filters is greater than or equal to the number of primary colors of the display screen under test. Generally speaking, the larger the number of bandpass filters, the higher the measurement accuracy, but the measurement time will also increase. In this technical solution, the number of bandpass filters can be reasonably determined according to actual needs.

[0014] In the above technical solution, in step S1, the display screen to be tested is controlled to display a first set of images, the first set of images including two or more different images, and the spectral measurement device measures the spectral power distribution under each image.

[0015] In the above technical solution, step S4 specifically includes: based on the spectral power distribution (S) of region A when the display screen displays the first set of images, as measured by the spectral measurement device in step S1. R (λ), S G (λ), S B (λ)) The spectral power distribution curves of each primary color of the display screen under test and the spectral peak positions of each primary color are obtained by analysis; according to step S3, the light color signal of region B when the display screen under test displays the second set of images is measured using an imaging device, wherein a specific combination of bandpass filters is selected according to the spectral peak positions of each primary color of the display screen under test, and the pixel response values ​​under different bandpass filters are obtained by an area array sensor, thereby calculating the peak intensity coefficients of each primary color at each position point in region B when the display screen under test displays the second set of images. The spectral power distribution of each primary color in area A of the display screen under test is superimposed according to the peak intensity coefficient of each primary color at position (i,j) in area B of the display screen under test. The spectral power distribution S(λ) at position (i,j) in area B of the display screen under test is then calculated according to formula (1). i,j After obtaining the spectral power distribution at each location point in region B, the brightness and chromaticity coordinates of each location point in region B are calculated.

[0016]

[0017] Among them, S R (λ) represents the spectral power distribution of the red primary color; S G (λ) represents the spectral power distribution of the green primary color; S B (λ) represents the spectral power distribution of the blue primary color; represents the peak intensity coefficient of each primary color.

[0018] It should be noted that the peak intensity coefficients of each primary color are... It generally refers to the absolute value coefficient.

[0019] Furthermore, in the above technical solution, the first set of images in step S1 and the second set of images in step S3 have one or more identical images. The response values ​​of region A obtained by the area array sensor under different bandpass filters under the same image are compared with the absolute peak intensity of the spectral power distribution of region A obtained in step S1 to obtain the peak intensity coefficients of each primary color under the combination of the area array sensor and each bandpass filter. Thus, when measuring any image of the display screen under test, the peak intensity coefficients of each primary color at each position point under the corresponding image are obtained.

[0020] Specifically, in the above technical solution, step S2 selects the bandpass filter (filter1, filter2...filter)n The optical path is sequentially entered to obtain the pixel response values ​​(D1, D2…D) of region A obtained by the area array sensor under the selected bandpass filter when the display screen under test displays a specific image. n And compared with the peak intensity (P1(λ1), P2(λ2)...P) of each bandpass filter in the spectral power distribution of region A obtained in step S1. n (λ n Compared to )), where λ1, λ2…λ n To correspond to the peak wavelength; according to formula (2), the area array sensor at the bandpass filter is obtained. n Peak intensity coefficients (k1, k2…k) of each pixel response. n The pixel response values ​​obtained by the area array sensor in step S3 are corrected using the peak intensity coefficients to obtain the peak intensity coefficients of each primary color at each position point in the corresponding image.

[0021]

[0022] Among them, D n The area A obtained by the area array sensor in the bandpass filter n Pixel response under; P n (λ) is the bandpass filter in the spectral power distribution of region A obtained in step S1. n Corresponding peak intensity; k n It is an area array sensor with a bandpass filter. n The peak intensity coefficient of each pixel response.

[0023] It should be noted that the response values ​​of the spectral measurement device under the corresponding image on the display screen and the response values ​​of each pixel of the array sensor under different bandpass filters can be calibrated in advance using a standard light source with a known light radiation intensity distribution. The standard light source is generally a continuous spectrum light source with standard values, including but not limited to standard A light sources, D65 energy spectrum light sources, etc. Based on the previous calibration, the response values ​​of each pixel obtained by the array sensor under different bandpass filters can be directly analyzed to obtain the peak intensity coefficients of each primary color at each location.

[0024] In the above technical solution, step S1 involves the first set of images including two or more images at different gray levels. Step S4 analyzes the primary color spectral power distribution of the first set of images at different gray levels. When analyzing the second set of images, the gray level of each location is determined based on the pixel response value. The primary color spectral power distribution of the corresponding gray level is combined with the primary color peak intensity coefficient to obtain the spectral power distribution of each location. The reason for measuring the spectral power distribution at multiple gray levels is that the spectral power distribution of some displays changes with different gray levels. This solution fully considers this problem, determines the gray level region based on the response value, and then calls upon a more suitable spectral power distribution of the same type to combine with the primary color peak intensity coefficient to obtain more accurate hyperspectral information.

[0025] Specifically, using the first set of images, the correspondence between the peak intensity coefficients of each primary color and the grayscale at each location point in region B when the display screen under test displays different grayscale images is obtained, and a database is established. When measuring the second set of images, the spectral power distribution of the primary color at the corresponding grayscale is found using the peak intensity coefficients of each primary color, and the spectral power distribution at each location point under the current grayscale is further obtained.

[0026] It should be noted that a typical display screen is composed of three primary pixels: red, blue, and green. Each color's sub-pixel outputs 256 gray levels, and the gray levels of the displayed image are generally expressed as (gray level R, gray level G, gray level B). The primary color image refers to a pure color image with 255 gray levels displayed by a single sub-pixel, i.e., pure red (255,0,0), pure green (0,255,0), and pure blue (0,0,255). An image composed of multiple primary colors is a mixed image displayed by the red, blue, and green primary color sub-pixels according to different required gray level ratios. When the display screen displays red, blue, and green with gray levels all at 255, the displayed image is pure white (255,255,255). Those skilled in the art should understand that display screens may contain other primary colors besides red, blue, and green, and the above description can also be referenced.

[0027] As a technical solution, in order to obtain more accurate luminance and chromaticity coordinates of each location point in region B, filters or combinations of filters that simulate the photometric or chromatic response of the human eye can be introduced to further correct the luminance and chromaticity coordinates of each location point in region B. Specifically, after step S4, the following steps are also included:

[0028] S5: Insert the filter (tristimulus value filter group) that simulates the photometric or chromatic response of the human eye into the measurement optical path, such as... Figure 5 As shown, the display screen under test is controlled to display the third set of images to be tested. The light beam emitted by the display screen enters the area array sensor through the filter, thereby obtaining the brightness value or tristimulus value of each position point in area B of the display screen under test.

[0029] S6: Based on the spectral power distribution obtained in step S4, a correction algorithm is used to obtain the brightness or tristimulus value correction coefficients for each location point in region B.

[0030] S7: Use the correction coefficient obtained in step S6 to correct the brightness value or tristimulus value obtained in step S5, and obtain the corrected brightness value or tristimulus value of each position point in area B of the third group of images.

[0031] Preferably, the third set of images in step S5 is the same as the second set of images.

[0032] In the above technical solution, the correction algorithm mentioned in step S6 includes, but is not limited to, spectral mismatch correction algorithm and ratio method.

[0033] In one specific implementation, the tristimulus value correction coefficient F of the location point (i,j) in the region of the display screen under test B is... * (S Z (λ)) i,j The tristimulus correction coefficient F for location point (i,j) in region B is calculated using the spectral mismatch correction algorithm and formula (3). * (S Z (λ)) i,j .

[0034]

[0035] Among them, S A (λ) represents the relative spectral power distribution of the standard light source; s rel () represents the actual spectral response curve obtained by using an area array sensor with a filter that simulates the colorimetric response of the human eye (x) rel (), y rel () and z rel ());S Z () represents the relative spectral power distribution of the display screen under test; V(λ) represents the three standard chromaticity observer functions x(), y(λ), and z(). The tristimulus correction coefficients F are obtained from this. * (S Z There are three corresponding ()), denoted as k(). i,j k() i,j k(z) i,j .

[0036] In another specific implementation, the tristimulus value correction coefficient F of the location point (i,j) in the region of the display screen under test B is... * (S Z The expression () is obtained by the ratio method, and there are three corresponding values, denoted as k(x). i,j k() i,jk(z) i,j It is calculated according to formula (4).

[0037]

[0038] in, The tristimulus values ​​are calculated for the spectral power distribution of each location point (i,j) obtained in step S4. The tristimulus values ​​for each location point (i,j) obtained in step S5.

[0039] Furthermore, in step S3, the second set of images consists of each primary color and a mixture of all primary colors at the same gray level; in step S4, the spectral power distribution at each position under these images is obtained; in step S5, filters simulating the colorimetric response of the human eye are sequentially applied; in step S6, the correction algorithm used is a matrix correction algorithm, and the tristimulus value correction coefficients at each position point are correction coefficient matrices; the third set of images in steps S5 and S7 are arbitrary display images.

[0040] It should be noted that the tristimulus value correction matrix for location point (i,j) in region B can be obtained using a matrix correction algorithm. Specifically, taking a red-blue-green three-primary-color display screen as an example, the images in the specific image set include three-primary-color images (pure red (255,0,0), pure green (0,255,0), pure blue (0,0,255)). Based on the spectral power distribution of region B of each image obtained in step S4, the tristimulus values ​​of the three primary colors can be calculated. Based on the tristimulus values ​​of the three primary colors of each image obtained in step S5 Tristimulus value correction matrix R i,j The result is obtained by formula (5).

[0041]

[0042]

[0043] After calculating and obtaining the tristimulus value correction matrix R, filters simulating the human eye's colorimetric response are sequentially inserted into the optical path to obtain the tristimulus values ​​M. i,j As shown in formula (6), then combined with the correction matrix R i,j The corrected tristimulus value M' i,j It is obtained by formula (7).

[0044]

[0045]

[0046] in, It measures the tristimulus values ​​before correction. These are the corrected tristimulus values.

[0047] Furthermore, to improve measurement efficiency and reduce measurement steps, a pre-set calibration coefficient database is used to achieve rapid measurement. Specifically, different types of calibration displays are used as calibration objects, and the calibration displays are controlled to display different grayscale images. Steps S1-S7 are repeated to obtain the tristimulus value correction coefficients of the calibration displays under different grayscale images and their correspondence with the tristimulus values ​​obtained by the filter channel simulating the human eye's colorimetric response. When measuring the display under test, the tristimulus values ​​obtained by the filter channel simulating the human eye's colorimetric response are directly used to call the tristimulus value correction coefficients in the database, thereby obtaining the corrected tristimulus values ​​of the display under test.

[0048] The beneficial effects of this invention are as follows: This invention provides a method for measuring the radiation of a display light field. Hyperspectral measurement can be achieved by selecting a small number of narrowband filters according to the display screen under test. In addition, by combining a filter group that simulates the colorimetric response of the human eye, the brightness and colorimetric measurements of each point on different grayscale images of the display screen under test can be achieved quickly and accurately. The measurement scheme is simple and easy to implement, which greatly improves the measurement efficiency and reduces the measurement cost. Attached Figure Description

[0049] Appendix Figure 1 This is a schematic diagram of area A and area B of the display screen under test.

[0050] Appendix Figure 2 This is a schematic diagram illustrating the principle of the technical solution of the present invention;

[0051] Appendix Figure 3 This is a schematic diagram of a display light field radiation measurement device provided in Embodiment 1 of the present invention;

[0052] Appendix Figure 4 This is a flowchart of a display light field radiation measurement method provided in Embodiment 1 of the present invention;

[0053] Appendix Figure 5 This is a schematic diagram of a display light field radiation measurement device provided in Embodiment 2 of the present invention;

[0054] Appendix Figure 6 This is a flowchart of a display light field radiation measurement method provided in Embodiment 2 of the present invention;

[0055] Appendix Figure 7 This is a flowchart of a display light field radiation measurement method provided in Embodiment 3 of the present invention;

[0056] Appendix Figure 8 This is a flowchart of a display light field radiation measurement method provided in Embodiment 4 of the present invention.

[0057] In the diagram, 1 is an optical lens, 2 is a reflector, 3 is a signal processing and output unit, 4 is an area array sensor, 5 is a color filter wheel, 5-1 is a bandpass filter, 5-2 is a filter that simulates the colorimetric response of the human eye, 6 is a spectral measurement device, and 7 is a coaxial drive device. Detailed Implementation

[0058] The specific embodiments of the present invention are described below with reference to the accompanying drawings. However, those skilled in the art should understand that the following embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Those skilled in the art should understand that modifications can be made to the following embodiments without departing from the scope and spirit of the present invention. The scope of protection of the present invention is defined by the appended claims.

[0059] Example 1

[0060] This embodiment discloses an imaging optical radiation measurement device, such as... Figure 3 As shown, the system includes an optical lens 1, a reflector 2, a signal processing and output unit 3, an area array sensor 4, a color filter wheel assembly 5, a spectral measurement device 6, and a coaxial drive device 7. The reflector 2 is located on the color filter wheel assembly 5, and its position can be switched via the coaxial drive device 7. When the reflector 2 is in the measurement optical path, it guides the light beam into the spectral measurement device 6 to obtain the spectral power distribution of a specified point on the display screen under test. When the reflector 2 is removed from the measurement optical path, the light beam emitted by the display screen under test passes through the bandpass filter 5-1 of the color filter wheel assembly 5 and is received by the area array sensor 4. The coaxial drive device 7 can sequentially insert different filters 5-1 into the measurement optical path. The signal processing and output unit 3 processes and calculates the signals received by the spectral measurement device 6 and the area array sensor 4.

[0061] This embodiment discloses a method for measuring the radiation of a display light field, such as... Figure 4 As shown, the response values ​​of the area array sensor under different bandpass filters and the spectral measurement device are calibrated beforehand using a standard A light source. Then, using the spectral measurement device, filters, and an imaging measurement device including the area array sensor, the hyperspectral information of the display screen under test is measured. Specifically, this includes:

[0062] A1: Use a standard light source with a known light radiation intensity distribution to calibrate the response of the spectral measurement device and the area array sensor under different bandpass filters, and obtain the corresponding correction coefficients;

[0063] A2: Control the display screen under test to display red, blue, and green primary color images. Use a spectral measurement device to measure the three primary color images respectively to obtain the spectral power distribution (S) of the three primary color images in area A of the display screen under test. R (λ) i,j S G (λ) i,jS B (λ) i,j );

[0064] A3: Based on the spectral power distribution of region A obtained in step A1, obtain the peak wavelength positions of the spectral power distribution of the three primary color images, and select three narrowband filters whose center wavelength is closest to the three peak wavelength positions.

[0065] A4: Control the display screen under test to display the image to be tested. Sequentially insert the three narrowband filters selected in step A3 into the optical path. The light from region B of the display screen under test is received by the area array sensor after passing through the imaging lens and the filters. The area array sensor obtains the response values ​​of each pixel under different bandpass filters, and then calculates the peak intensity coefficients of each primary color at each position point in region B when the display screen under test displays the image to be tested. Each location point in the B region of the display screen under test corresponds to a specific pixel point of the area array sensor;

[0066] A5: By analyzing the spectral power distribution (S) of each primary color in area A of the display screen under test... R (λ), S G (λ), S B (λ) According to the peak intensity coefficient of each primary color at each location point in area B of the display screen under test. Superimpose using the formula The spectral power distribution S(λ) at each location (i,j) in region B of the display screen under test is calculated. i,j Among them, S R (λ) i,j S represents the spectral power distribution of the red primary color. G (λ) i,j The spectral power distribution of the green primary color, S B (λ) i,j The spectral power distribution of the blue primary color. These are the peak intensity coefficients for each primary color; in this embodiment, the peak intensity coefficients for each primary color refer to absolute value coefficients.

[0067] A6: After obtaining the spectral power distribution of each location point in region B, the brightness and chromaticity coordinates of each location point in region B are obtained by calculation.

[0068] Example 2

[0069] This embodiment discloses an imaging optical radiation measurement device, such as... Figure 5As shown, the system includes an optical lens 1, a reflector 2, a signal processing and output unit 3, an area array sensor 4, a color filter wheel assembly 5, a spectral measurement device 6, and a coaxial drive device 7. The reflector 2 is located on the color filter wheel assembly 5, and its position can be switched via the coaxial drive device 7. When the reflector 2 is in the measurement optical path, it guides the light beam into the spectral measurement device 6 to obtain the spectral power distribution of a specified point on the measured object. When the reflector 2 is removed from the measurement optical path, the light beam from the measured object is received by the area array sensor 4 through the color filter wheel assembly 5. The color filter wheel 5 contains a bandpass filter 5-1 and a filter 5-2 that simulates the colorimetric response of the human eye. The coaxial drive device 7 can sequentially insert different filters into the measurement optical path. The signal processing and output unit 3 processes and calculates the signals received by the spectral measurement device 6 and the area array sensor receiver 4.

[0070] This embodiment also discloses a method for measuring the radiation of a display light field, such as... Figure 6 As shown, the measurement steps include:

[0071] B1: Use a standard light source with a known light radiation intensity distribution to calibrate the response of the spectral measurement device and the area array sensor under different bandpass filters, and obtain the corresponding correction coefficients;

[0072] B2: Control the display screen under test to display red, blue, and green primary color images respectively. Use a spectral measurement device to measure the three primary color images respectively to obtain the spectral power distribution (S) of the three primary color images in area A of the display screen under test. R (λ) i,j S G (λ) i,j S B (λ) i,j );

[0073] B3: Based on the peak wavelength positions of the spectral power distribution of the three primary color images in region A, select three narrowband filters whose center wavelength is closest to the three peak wavelength positions.

[0074] B4: Control the display to show the image to be tested. Sequentially insert the three narrowband filters selected in step B3 into the optical path. The light from region B of the display screen under test is received by the area array sensor after passing through the imaging lens and the filters. The area array sensor obtains the response values ​​of each pixel under different bandpass filters, and then calculates the peak intensity coefficients of each primary color at each position point in region B when the display screen under test shows the image to be tested. Each location point in the B region of the display screen under test corresponds to a specific pixel point of the area array sensor;

[0075] B5: By analyzing the spectral power distribution (S) of each primary color in area A of the display screen under test... R (λ), S G(λ), S B (λ) According to the peak intensity coefficient of each primary color at each location point in area B of the display screen under test. Superimpose using the formula The spectral power distribution S(λ) at each location (i,j) in region B of the display screen under test is calculated. i,j Among them, S R (λ) i,j S represents the spectral power distribution of the red primary color. G (λ) i,j The spectral power distribution of the green primary color, S B (λ) i,j The spectral power distribution of the blue primary color. These are the peak intensity coefficients for each primary color; in this embodiment, the peak intensity coefficients for each primary color refer to absolute value coefficients.

[0076] B6: Filters simulating the colorimetric response of the human eye are sequentially inserted into the optical path. The light beam emitted from the display screen under test enters the area array sensor through the filters, thereby obtaining the tristimulus values ​​M at various locations in region B of the display screen under test with the same image. i,j ;

[0077] B7: The spectral power distribution S(λ) of each location point (i,j) in region B of the display screen under test, obtained from step B5. i,j The response curves of the tristimulus value filter channels were used, and the tristimulus value correction coefficients F at each location point in region B were obtained using a spectral mismatch correction algorithm. * (S Z (λ)) i,j According to the formula Calculations show that Where S A (λ) represents the relative spectral power distribution of the standard light source; s rel () represents the actual spectral response curve obtained by using an area array sensor with a filter that simulates the colorimetric response of the human eye (x) rel (), y rel () and z rel ());S Z () represents the relative spectral power distribution of the display screen under test; V(λ) represents the three standard chromaticity observer functions x(), y(), and z(). The tristimulus correction coefficients F are obtained from this. * (S Z There are three corresponding ()), denoted as k(). i,j k() i,j k(z) i,j .

[0078] B8: Tristimulus value correction coefficient F obtained in step B7.* (S Z ()) The tristimulus value M obtained in step B6 i,j Perform calibration to obtain the calibrated tristimulus values ​​M' for each location point in area B of the current display screen. i,j Furthermore, the brightness and chromaticity coordinates of each point in area B of the current display screen are obtained.

[0079] Example 3

[0080] This embodiment also discloses another imaging-based optical radiation measurement method, such as... Figure 7 As shown, the measurement steps include:

[0081] C1: Controls the display screen under test to show a pure white image;

[0082] C2: Use a spectral measurement device to obtain the spectral power distribution of area A of the display screen under the corresponding image, and select three or more specific bandpass filters according to the spectral power distribution;

[0083] C3: Control the display screen under test to display the primary color image, and sequentially insert the bandpass filter selected in step C2 into the optical path. The light in area B of the display screen under test is incident through the imaging lens and received by the area array sensor through the filter. The position point in area B of the display screen under test corresponds to the specific pixel point of the area array sensor. The primary color image refers to a pure red, pure green or pure blue image.

[0084] C4: Based on the pixel response values ​​of the area array sensor in step S3 and the spectral power distribution of area A of the display screen under test in step C1, calculate the spectral power distribution of each point in area B of the current screen of the display screen under test, and then calculate the tristimulus values ​​of the three primary colors of each screen.

[0085] C5: Control the display screen under test to sequentially display pure red, pure green, and pure blue images. Repeat steps C2-C4 to obtain the spectral power distribution (S) at each location point in region B of the pure red, pure green, and pure blue images. R (λ), S G (λ), S B (λ));

[0086] C6: Control the display screen under test to sequentially display pure white, pure red, pure green, and pure blue images. Simulate human eye color response by sequentially inserting filters into the optical path. Light from region B of the display screen under test is incident through the imaging lens and received by the area array sensor via the filters, obtaining the tristimulus values ​​of the pure color images at each location point in region B.

[0087] C7: Tristimulus values ​​obtained from the spectral power distribution based on C5. and the tristimulus values ​​obtained from C6 Through formula The tristimulus value correction matrix R is calculated and obtained. i,j ;in,

[0088] C8: Controls the display screen to show the image to be tested, and sequentially inserts filters simulating the color response of the human eye into the optical path to obtain tristimulus values ​​M. i,j Combined with the tristimulus value correction matrix R obtained from C7 i,j According to formula M' i,j = i,j · i,j The corrected tristimulus values ​​M' of each position point in area B of the current display screen are calculated. i,j Furthermore, the brightness and chromaticity coordinates of each point in area B of the current display screen are obtained.

[0089] Example 4

[0090] This embodiment also discloses another imaging-based optical radiation measurement method, such as... Figure 8 As shown, the measurement steps include:

[0091] D1: Use a standard light source with a known light radiation intensity distribution to calibrate the response of the spectral measurement device and the area array sensor under different bandpass filters, and obtain the corresponding correction coefficients;

[0092] D2: Control the display screen under test to display different grayscale images, and use a spectral measurement device to measure each grayscale image to obtain the spectral power distribution (S) of each grayscale image in area A of the display screen under test. Rt (λ), Gt (λ), Bt (λ)), where t is 0-255 representing the grayscale level of the grayscale image;

[0093] D3: Based on the spectral power distribution of region A obtained in step D2, obtain the peak wavelength positions of the spectral power distribution of the three primary color images, and select three narrowband filters whose center wavelength is closest to the three peak wavelength positions.

[0094] D4: Control the display screen under test to display different grayscale images described in step D2. Sequentially insert the three narrowband filters selected in step D3 into the optical path. The light from region B of the display screen under test is received by the area array sensor after passing through the imaging lens and the filters. The area array sensor obtains the response values ​​of each pixel under different bandpass filters, and then calculates the peak intensity coefficients of each primary color at each position point in region B when the display screen under test displays grayscale image t. Each location point in the B region of the display screen under test corresponds to a specific pixel point of the area array sensor;

[0095] D5: Establish the peak intensity coefficients of each primary color from steps D1 to D4. Spectral power distribution (S Rt (λ), Gt (λ), Bt (λ)) and the corresponding database of grayscale t.

[0096] D6: Control the display screen under test to display the image to be tested. Sequentially insert the three narrowband filters selected in step D3 into the optical path. The light from region B of the display screen under test is received by the area array sensor after passing through the imaging lens and the filters. The area array sensor obtains the response values ​​of each pixel under different bandpass filters, and then calculates the peak intensity coefficients of each primary color at each position point in region B when the display screen under test displays the image to be tested.

[0097] D7: Based on the peak intensity coefficients of each primary color at various locations in region B when the screen under test displays the image under test, obtained in step D6. In step D6, a search is performed in the database to obtain the corresponding grayscale and the spectral power distribution (S) of each primary color. Rt (λ), Gt (λ), Bt (λ)).

[0098] D8: By analyzing the spectral power distribution (S) of each primary color in area A of the display screen under test... Rt (λ), Gt (λ), Bt (λ) According to the peak intensity coefficient of each primary color at each location point in area B of the display screen under test. Superimpose using the formula The spectral power distribution S at each location (i,j) in region B of the display screen under test was calculated. t (λ) i,j Among them, S Rt (λ) represents the spectral power distribution of red at gray level t, S Gt (λ) i,j S represents the spectral power distribution of green at gray level t. Bt (λ) i,j The spectral power distribution of blue at gray level t is shown. represents the peak intensity coefficient of each primary color at grayscale t; in this embodiment, the peak intensity coefficient of each primary color refers to the absolute value coefficient.

[0099] D9: After obtaining the spectral power distribution of each location point in region B, the brightness and chromaticity coordinates of each location point in region B are obtained by calculation.

Claims

1. A method of displaying light field radiometry, characterized in that, The measurement of hyperspectral information of a display screen under test is achieved using a spectral measurement device, a filter, and an imaging measurement device including an area array sensor. The specific steps include: S1: Control the display screen under test to display the first set of images, and use the spectral measurement device to obtain the spectral power distribution of region A of the display screen under test under the corresponding image; S2: Based on the spectral power distribution of region A obtained in step S1, obtain the primary color peak wavelength of the display screen under test, and select two or more specific bandpass filters, the conduction band of the selected bandpass filters covering the primary color peak wavelength of the display screen under test. S3: Control the display screen under test to display the second set of images, and sequentially insert the filters selected in step S2 into the optical path. The light from area B of the display screen under test is received by the area array sensor through the imaging lens and the filter. Each position point in area B of the display screen under test is imaged onto the corresponding pixel point of the area array sensor, and the area array sensor obtains the corresponding pixel response value. S4: Based on the pixel response value of the area array sensor in step S3 and the spectral power distribution of area A of the display screen under test in step S1, calculate the spectral power distribution of each position point in area B when the display screen under test displays the second set of images.

2. A method of displaying light field radiometry according to claim 1, wherein, Each primary color of the display screen under test corresponds to at least one bandpass filter, and the number of bandpass filters is greater than or equal to the number of primary colors of the display screen under test.

3. A method of displaying light field radiometry according to claim 1, wherein, In step S1, the first set of images includes two or more different images, and the spectral measurement device measures the spectral power distribution under each image.

4. The method for measuring the radiation of a display light field as described in claim 1, characterized in that, Step S4 specifically includes: analyzing the spectral power distribution of each primary color of the display screen under test based on the spectral power distribution of region A of the display screen under test measured in step S1. Based on the pixel response values ​​of the area array sensor in step S3, the position points of the display screen under test when displaying the second set of images are calculated. Peak intensity coefficients of each primary color () The spectral power distribution at each location point is obtained by combining the spectral power distribution of each primary color with the peak intensity coefficient of each primary color. .

5. The method for measuring the radiation of a display light field as described in claim 4, characterized in that, The first set of images in step S1 and the second set of images in step S3 have one or more identical images. The response values ​​of region A obtained by the array sensor under different bandpass filters in the same image are compared with the peak intensity of the spectral power distribution of region A obtained in step S1 to obtain the primary color peak intensity coefficient under the combination of the array sensor and each bandpass filter. Then, when measuring any image of the display screen under test, the peak intensity coefficient of each primary color at each position point under the corresponding image is obtained.

6. A method for measuring the radiation of a display light field as described in any one of claims 4 or 5, characterized in that, In step S1, the first set of images includes two or more images at different gray levels; in step S4, the spectral power distribution of primary colors in different gray levels of the display screen under test is analyzed, so that while calculating the peak intensity coefficient of primary colors at each position point when the display screen under test displays the second set of images, the gray level at each position point is determined, and the spectral power distribution of primary colors at each position point is obtained by combining the spectral power distribution of primary colors at the corresponding gray level with the peak intensity coefficient of primary colors.

7. The method for measuring the radiation of a display light field as described in claim 1, characterized in that, The following steps are included after step S4: S5: Insert a filter that simulates the light intensity or color intensity response of the human eye into the optical path, control the display screen under test to display the third set of images to be tested, and the area array sensor obtains the brightness value or tristimulus value of each position point in area B of the display screen under test. S6: Based on the spectral power distribution obtained in step S4, a correction algorithm is used to obtain the brightness or tristimulus value correction coefficients for each location point in region B. S7: Use the correction coefficient obtained in step S6 to correct the brightness value or tristimulus value obtained in step S5, and obtain the corrected brightness value or tristimulus value of each position point in area B of the third group of images.

8. The method for measuring the radiation of a display light field as described in claim 7, characterized in that, The third set of images in step S5 is the same as the second set of images. The correction algorithm in step S6 includes a spectral mismatch correction algorithm and a ratio method.

9. The method for measuring the radiation of a display light field as described in claim 7, characterized in that, The second set of images in step S3 consists of each primary color and a mixture of all primary colors at the same gray level. In step S4, the spectral power distribution at each position under these images is obtained. In step S5, filters that simulate the colorimetric response of the human eye are sequentially switched in. The correction algorithm used in step S6 is a matrix correction algorithm, and the tristimulus value correction coefficients at each position point are correction coefficient matrices. The third set of images in steps S5 and S7 are arbitrary display images.

Images