A system for measuring color discrimination

Abstract

The application discloses a color resolution measurement system, comprising a parameter acquisition module, a visual stimulus generation module, a human-computer interaction module, a process control module and a data recording and analysis module. The parameter acquisition module acquires measurement parameters; the visual stimulus generation module generates color visual stimuli for measurement; the human-computer interaction module presents the stimuli to the measured individual and acquires the recognition of the visual stimuli by the measured individual; the process control module controls the measurement process; and the data recording and analysis module records the measurement data and analyzes and determines the color resolution threshold. The color resolution measurement system provided by the application can quantize the resolution capability of the measured individual to various colors through targeted visual stimulus design, measurement process control and data analysis method, can adjust the measurement precision through parameter setting, has simple task design and operation mode, is suitable for animal function evaluation and has a broader application prospect.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of color discrimination detection, and particularly relates to a color discrimination measurement system. BACKGROUND

[0002] For a biological individual, color discrimination is an important visual function, which can help the biological individual find an object only by color difference in the case that the object and the background have the same brightness.

[0003] However, there are very few measuring devices or systems for measuring the color discrimination of a biological individual. The color blindness and weakness detection chart is a relatively familiar tool for checking color discrimination function. However, the color blindness and weakness detection chart can only qualitatively detect color blindness or weakness, and it is difficult to quantify the strength of color discrimination. For example, even if they are normal people, there can be a big difference in the ability to distinguish red and green color differences. Some people have strong distinguishing ability, and some people have weak distinguishing ability. However, such differences in distinguishing ability cannot be distinguished by the color blindness and weakness detection chart as long as they do not reach the level of color blindness or weakness. In addition, the color blindness and weakness detection chart can only detect a few limited colors such as red, green, blue, and purple, and cannot be extended to other colors commonly seen in real life. Finally, due to the limitations of operation mode and application understanding, the color blindness and weakness detection chart is almost impossible to be used for animal function measurement. SUMMARY

[0004] The present application aims at the deficiencies of the prior art and provides a color discrimination measurement system technical solution, which can quantify the distinguishing ability of the measured individual to multiple colors through targeted visual stimulation design, measurement process control and data analysis method, and can adjust the measurement accuracy through parameter setting, and also has a simple task design and operation mode, which is suitable for animal function evaluation and has a wider application prospect.

[0005] In order to solve the above technical problems, the present application adopts the following technical solutions:

[0006] A color discrimination measurement system comprises:

[0007] A parameter acquisition module acquires measurement parameters, including a first color and a second color for distinguishing, a minimum change unit of color contrast of the two colors, and a maximum test amount;

[0008] A visual stimulation generation module generates color visual stimulation for measurement based on the parameters acquired by the parameter acquisition module, the system built-in parameters, and the color contrast transmitted by the process control module;

[0009] A human-computer interaction module presents the generated background and color visual stimulation to the measured individual, and acquires the correct / incorrect identification of the color visual stimulation by the measured individual;

[0010] a flow control module, which adjusts the color contrast of the color visual stimulus based on the reaction of the measured individual to the color visual stimulus until the recognition of the color visual stimulus by the measured individual meets the specified requirements;

[0011] a data recording and analysis module, which records the color contrast of all color visual stimuli in the measurement process and the reaction data of the measured individual, and analyzes and determines the color discrimination threshold of the first color and the second color under the specified correct recognition rate.

[0012] Further, the minimum change unit of the color contrast is 0.5-6.0 dB, and gradually decreases with the measurement process.

[0013] Further, the initial value of the minimum change unit of the color contrast is 2.0 dB, and is adjusted to 1 / 2 of the initial value, i.e. 1.0 dB, after completing the initial 6 test measurements.

[0014] Further, the parameter acquisition module also needs to acquire parameters related to the visual stimulus attributes, including the size of the visual stimulus, the presentation time, and the auxiliary features related to the visual stimulus recognition, and there are two or more visual stimulus attribute options in the test for the measured individual to recognize, and the two attribute options are different by π / 2 radian, for example, π / 4 and 3π / 4.

[0015] Further, the size of the visual stimulus is indicated by diameter, and the diameter size is 2.5-6.0 degrees of visual angle, and the presentation time of the visual stimulus is 1.0-5.0 seconds, and preferably, the presentation time is 3.0 seconds.

[0016] Further, the auxiliary features related to the visual stimulus recognition are shape, orientation or direction, and the auxiliary features are preferably direction features.

[0017] Further, the first color and the second color for recognition are display tricolors of a display device, or other colors mixed and adjusted by display tricolors in a certain proportion.

[0018] Further, the color visual stimulus is mixed by the first color and the second color and presented on a uniform background composed of the first color, and the brightness of the color visual stimulus and the background is exactly the same, and only through color differentiation, the recognition difficulty of the color visual stimulus is indicated by the color contrast C of the color visual stimulus.

[0019] Further, the color visual stimulus is a figure with specific shape features or simple meaning, and should meet the following requirements:

[0020] ;

[0021] ;

[0022] wherein C is the chromatic contrast of the chromatic visual stimulus: L mean，color1 represents the luminance of the background composed of the first color, l pattern，color1 represents the luminance corresponding to the first color in the chromatic visual stimulus, l pattern，color2 represents the luminance corresponding to the second color in the chromatic visual stimulus.

[0023] Further, in the flow control module, the specific steps of adjusting the chromatic contrast of the chromatic visual stimulus are as follows:

[0024] S1-1, if the current trial is the first trial, the chromatic contrast of the chromatic visual stimulus uses a first value, and the preferred first value is 0.50;

[0025] S1-2, if the result of the measured individual recognizing the chromatic visual stimulus in the previous trial is correct, the chromatic contrast of the chromatic visual stimulus is reduced by 1 minimum change unit in the next trial; if the recognition result in the previous trial is incorrect, the chromatic contrast of the chromatic visual stimulus is increased by a first specified number of minimum change units in the next trial; wherein the first specified number is a positive integer greater than 1, and the preferred first specified number is 3;

[0026] S1-3, if the number of trials presented to the measured individual has reached the set maximum test amount, or the chromatic contrast of the chromatic visual stimulus presented to the measured individual repeatedly fluctuates within a first specified range, or the chromatic contrast of the chromatic visual stimulus has reached the upper and lower limits of the measured range of chromatic contrast for 3 times or a total of 5 times, the test is terminated; preferably, the first specified range is 5 chromatic contrast minimum change units.

[0027] Further, in the data recording and analysis module, the specific steps of analyzing and determining the color discrimination threshold value include:

[0028] S2-1, based on the recorded reaction data, list the chromatic contrast used in each trial completed normally, and the correct / incorrect situation of the measured individual recognizing the chromatic visual stimulus;

[0029] S2-2, based on the list sorted out in S2-1, select the chromatic contrast where the change trend of the chromatic contrast changes in the measurement process, and all are recorded as C cri ;

[0030] S2-3, if the number of C cri is less than a second specified number, the analysis is ended and a prompt "threshold value cannot be determined, should be re-measured" is given; otherwise, proceed to step S2-4, and the preferred second specified number is 8;

[0031] S2-4, if the difference between the maximum value and the minimum value of all C cri is not more than a third specified number of contrast minimum change units, then the reciprocal of the arithmetic mean of all C cri is determined to be the color resolution threshold of the measured individual for the first color and the second color; otherwise, go to S2-5, and the preferred third specified number is 5;

[0032] S2-5, among all C cri , in the order of occurrence, the first 3 or the first 4 C cri are removed, so that the number of remaining C cri is even, and then the reciprocal of the arithmetic mean of all remaining C cri is taken, and the result is the color resolution threshold of the measured individual for the first color and the second color.

[0033] Further, the human-computer interaction module comprises a color brightness evaluation and conversion unit, which regularly evaluates the brightness of the screen when the display device presents any one of the three primary colors, and converts the theoretical brightness of the first color and the second color required to be presented by each pixel point of the color visual stimulus into the closest real application hardware brightness actual level closest to the theoretical requirement;

[0034] The specific working steps of the color brightness evaluation and conversion unit are as follows:

[0035] S3-1, using any one of the display three primary colors, in the single color display mode, according to the hardware brightness level indicated by the display device bit depth, the actual brightness of the screen under each hardware brightness level is measured and recorded in sequence;

[0036] S3-2, the evaluation data is fitted using the following formula to obtain the fitting parameters and determine the functional relationship between the screen actual brightness and the hardware brightness level:

[0037] ;

[0038] ;

[0039] ;

[0040] Wherein, lum c1 , lum c2 , lum c3 are the actual measured brightness of the screen when using one of the display three primary colors alone; level c1 , level c2 , level c3 are the hardware brightness levels; lum c1，max , lum c2，max , lumc3，max respectively are the maximum values of the measured brightness of the screen when one of the three primary colors is displayed alone; a1 c1 , a1 c2 , a1 c3 , a2 c1 , a2 c2 , a2 c3 , b1 c1 , b1 c2 , b1 c3 , BP c1 , BP c2 , BP c3 are fitting parameters; min(·) is the minimum function; max(·) is the maximum function;

[0041] S3-3, when presenting the color visual stimulus, according to the first color and the second color, the proportional relationship between the display three primary colors, and the luminance of the first color and the second color required to be presented on each pixel point of the color visual stimulus transmitted by the visual stimulus generation module, the luminance of each color required to be presented in the display three primary colors is determined, and the specific formula is as follows:

[0042] ;

[0043] ;

[0044] ;

[0045] Wherein, lum(x,y) c1 , lum(x,y) c2 and lum(x,y) c3 represent the luminance of the point with coordinates (x, y) on the color visual stimulus image, which respectively corresponds to the three colors c1, c2 and c3 in the display three primary colors; l(x,y) color1 and l(x,y) color2 represent the luminance of the point with coordinates (x, y) on the color visual stimulus image, which respectively corresponds to the first color color1 and the second color color2 required to be distinguished; Ratio color1，c1 , Ratio color1，c2 and Ratio color1，c3 represent the proportion of the luminance of c1, c2 and c3 in the mixed light of the first color color1 when the display three primary colors c1, c2 and c3 are mixed and adjusted; Ratio color2，c1 , Ratio color2，c2 and Ratio color2，c3represents the proportion of the brightness of c1, c2 and c3 in the mixed light of the second color when the second color color2 is mixed by using the display tricolors c1, c2 and c3;

[0046] S3-4, according to the function relationship between the actual screen brightness and the hardware brightness level obtained in S3-2, the lum(x, y) obtained in S3-3 is converted into the hardware brightness level level c1 , lum(x, y) c2 , lum(x, y) c3 corresponding to the display tricolors that should be used when actually presented c1 , level c2 and level c3 , according to the principle of rounding, level c1 , level c2 and level c3 is converted into the level closest to the theoretical value for the display device , c1 , level , c2 and level , c3 , that is

[0047] ;

[0048] ;

[0049] ;

[0050] wherein level c1 , level c2 and level c3 are the hardware brightness theoretical levels that should be used when presenting the color visual stimulus, calculated according to the formula in S3-2, level , c1 , level , c2 and level , c3 are the hardware brightness actual levels actually used after conversion;

[0051] S3-5, calculate the difference between the hardware brightness theoretical level that should be used when presenting the color visual stimulus and the hardware brightness actual level actually used after conversion, if the absolute value of the difference between the hardware brightness theoretical level and the hardware brightness actual level of any color in the display tricolors exceeds 0.10, prompt the data recording and analysis module that the color visual stimulus presentation is inaccurate, and mark the test number presenting the color visual stimulus as "abnormal".

[0052] Furthermore, in the data recording and analysis module, the steps for analyzing and determining the color resolution threshold also include:

[0053] Before executing S2-1, determine the number of trials marked as "abnormal". If the number is less than 10% of the total number of trials, then execute S2-1.

[0054] If this number is greater than or equal to 10% of all trials, list all color contrasts that appeared in the trials that were completed normally. Based on the correct / incorrect identification of the measured individuals in these trials, calculate the accuracy rate of the measured individuals in distinguishing colored visual stimuli under the above color contrast conditions. Then find the color contrast with a resolution rate greater than the specified accuracy rate and closest to the specified accuracy rate, and the color contrast with a resolution rate less than the specified accuracy rate and closest to the specified accuracy rate. Use linear interpolation to calculate the color contrast under the specified accuracy rate. This is the color discrimination threshold for the measured individuals to distinguish the first color from the second color.

[0055] Furthermore, in steps S1-3, the color contrast presented to the measured individual fluctuates repeatedly within a first specified range, specifically referring to: using the last obtained C... cri Based on the first specified range, a fourth specified number of C has been accumulated. cri The fourth specified quantity ranges from 6 to 20, with the preferred fourth specified quantity being 8.

[0056] The present invention, by adopting the above-described technical solution, has the following beneficial effects:

[0057] This invention can quantify the ability of an individual to distinguish multiple colors through targeted visual stimulus design, measurement process control, and data analysis methods. The measurement accuracy can be adjusted through parameter settings. It also features simple task design and operation, making it suitable for evaluating animal functions and possessing broader application prospects. Attached Figure Description

[0058] The present invention will be further described below with reference to the accompanying drawings:

[0059] Figure 1 This is an example diagram of a color resolution measurement system according to the present invention;

[0060] Figure 2 This is a schematic diagram of the color visual stimulation of the present invention;

[0061] Figure 3 This is a schematic diagram of the testing process of the present invention. Detailed Implementation

[0062] like Figure 1As shown, it is a color resolution measurement system of the present application, comprising:

[0063] (1) Parameter acquisition module, acquiring measurement parameters, including the first color and the second color for resolution, the minimum change unit of the color contrast of the two colors, and the maximum test amount;

[0064] (2) Visual stimulation generation module, generating color visual stimulation for measurement based on the parameters acquired by the parameter acquisition module, the system built-in parameters and the color contrast transmitted by the process control module;

[0065] (3) Human-computer interaction module, presenting the generated background and color visual stimulation to the measured individual, and acquiring the identification correct / incorrect situation of the color visual stimulation by the measured individual;

[0066] (4) Process control module, continuously adjusting the color contrast of the color visual stimulation based on the reaction situation of the measured individual to the color visual stimulation, until the identification situation of the color visual stimulation by the measured individual reaches the specified requirements;

[0067] (5) Data recording and analysis module, recording the color contrast of all color visual stimulations in the measurement process and the reaction data of the measured individual, and analyzing and determining the color resolution threshold of the first color and the second color under the specified resolution correct rate based on the above.

[0068] The maximum test amount acquired by the parameter acquisition module is related to the test completion time, and also has a certain influence on the measurement result. If the maximum test amount is small, the test completion time will be relatively short, but accurate and effective test results may not be obtained (for specific content, please refer to the introduction of the process control module and the data recording and analysis module below). If the maximum test amount is large, accurate and effective test results can be obtained, but the test completion time is relatively long. Therefore, generally, the maximum test amount will be selected as a moderate value, for example, 60-120 trials (trials). Preferably, the maximum test amount can be set to 80 trials. Among them, a trial represents "presenting a stimulus and accepting the identification situation of the measured individual to the stimulus presented this time".

[0069] The minimum change unit of the color contrast acquired by the parameter acquisition module is directly related to the measurement accuracy. The minimum change unit of the color contrast is equivalent to the minimum scale of the measuring tool (for example, meter ruler or vernier caliper) in length measurement. Therefore, the smaller the minimum change unit, the higher the measurement accuracy. Of course, the minimum change unit is not the smaller the better. According to the process control rules of the present system (for reference, please refer to the introduction of the process control module below), the smaller the minimum change unit, the more difficult the process of changing the initial level of presenting the stimulus to the level corresponding to the real functional level of the measured individual during measurement (see Figure 3The longer the "Phase One" in the process is, the more test times and time are consumed. In the case of fixed test times, the more test times consumed in the "Phase One", the less test times in the "Phase Two" which has a decisive influence on the measurement result, the less data obtained in the "Phase Two", and the lower accuracy of the measurement result (the analysis method of data in the "Phase Two" and its relationship with the measurement result will be described later). Therefore, it is unnecessary to pursue too small a minimum change unit.

[0070] Generally, the minimum change unit should be determined before the measurement and kept stable during the measurement. The stable minimum change unit means that the gap between two adjacent difficulty levels defined by the minimum change unit is fixed. This helps to control the error in the measurement process and ensure the accuracy of the measurement result. In practical application, the minimum change unit of contrast ratio can be defined by using the commonly used dB method in engineering, which is specifically:

[0071] ;

[0072] Therefore, the difference of 1.0 dB is about 1.122 times the difference of contrast ratio. In practical use, it is generally selected within the range of 0.5-6.0 dB as appropriate.

[0073] In addition, in order to quickly pass the "Phase One" in the test process (see Figure 3 ), a larger contrast ratio minimum change unit can be selected in the first few test times of the measurement. Preferably, the initial value of the color contrast minimum change unit is 2.0 dB, and after completing the initial 6 test times of measurement, it is adjusted to 1 / 2 of the initial value, i.e. 1.0 dB.

[0074] The first color and the second color obtained by the parameter acquisition module are not limited in principle and can be display tricolors of the display device or other colors mixed and adjusted from the display tricolors according to a certain proportion. But from the practical measurement operation restrictions (see the introduction of the related process control module and data recording and analysis module later), it can be seen that selecting the first color and the second color from the display tricolors of the display device can obtain better results and more accurate results. Generally, the display tricolors of the display device are red, green and blue, and preferably the first color is red and the second color is green.

[0075] The parameter acquisition module can also acquire parameters related to the visual stimulus attributes, including the size of the visual stimulus. The size of the visual stimulus is usually indicated by the diameter, with the unit of visual angle. The macular area of the human eye is generally not more than 6 degrees of visual angle, so the value range of the stimulus size is generally 2.5-6.0 degrees of visual angle. The parameters related to the visual stimulus attributes also include the presentation time of the visual stimulus, and the value range of the presentation time is 1.0-5.0 seconds. Preferably, the presentation time is 3.0 seconds. The parameters related to the visual stimulus attributes also include auxiliary features related to stimulus recognition. When the measured individual recognizes the stimulus, the recognition is mainly based on color contrast information, but the perception of color contrast cannot be directly fed back. Therefore, the stimulus should include auxiliary features, including shape, orientation or direction, such as Figure 2 shape features. Figure 2 In the above-mentioned

[0076] After acquiring the necessary parameters, the visual stimulus generation module can generate color visual stimuli for measurement based on the parameters acquired by the parameter acquisition module, the system built-in parameters, and the color contrast delivered by the process control module. It should be noted that simpler graphic stimuli have more intuitive meaning, are easier to recognize, and are more conducive to animal testing.

[0077] The color visual stimulus is presented on a uniform background, which has the same brightness as the background but presents different colors. The background only contains the first color, and the color of the color visual stimulus is a mixture of the first color and the second color. The difficulty of recognizing the color visual stimulus is indicated by the color contrast C of the color visual stimulus.

[0078] The color visual stimulus is a pattern drawn using lines of uniform thickness. When drawing, the following requirements should be met:

[0079] ;

[0080] ;

[0081] wherein C is the color contrast of the color visual stimulus: L mean，color1 represents the brightness of the background composed of the first color, l pattern，color1 represents the brightness corresponding to the first color in the color visual stimulus, l pattern，color2 represents the brightness corresponding to the second color in the color visual stimulus.

[0082] Some color pattern stimuli are as follows Figure 3The first color of the left 3 columns is red and the second color is green. The first color of the rightmost column is blue and the second color is green. The left two columns of the figure use the letter stimuli O and Q, and the right two columns use simple figure stimuli. The color contrast of the left first column and the right two columns is the maximum value 1.0, which is very easy to identify, while the color contrast of the left second column is smaller, which is relatively difficult to identify.

[0083] To ensure that the brightness values of the first color and the second color of the visual stimulus actually presented to the measured individual are accurately achieved, the color brightness evaluation and conversion unit is included in the human-computer interaction module. The brightness of the screen when displaying any one of the three primary colors is evaluated regularly, and the theoretical brightness of the first color and the second color required to be presented on each pixel point of the color visual stimulus is converted to the closest theoretical requirement and real application hardware brightness actual level.

[0084] It should be noted that due to the variability of the display device hardware settings (for example, the "brightness", "contrast" and "Gamma" parameter options adjusted by buttons on the display), and the impact of display device hardware aging during use, the brightness distribution of the display device under different hardware brightness levels will inevitably change during use. Therefore, regular evaluation of the display device is a necessary prerequisite to ensure the accuracy of visual stimulus display.

[0085] The hardware brightness level of the display device is usually determined by the display bit depth. When the display bit depth is 8 bits, the hardware brightness level of the display device is divided into 2^8=256 levels; when the display bit depth is 10 bits, the hardware brightness level of the display device is divided into 2^10=1024 levels. More intuitively, when the display bit depth is 8 bits, the 256 hardware brightness levels correspond to the brightness of the 256 cases of "r=0, g=0, b=0", "r=1, g=1, b=1" to "r=255, g=255, b=255" in the color palette; when the display bit depth is 10 bits, the 1024 hardware brightness levels correspond to the brightness of the 1024 cases of "r=0, g=0, b=0", "r=1, g=1, b=1" to "r=1023, g=1023, b=1023" in the color palette.

[0086] It is worth mentioning that, in the absence of special processing, the default setting used by display devices when displaying images is "linear relationship between rgb value and brightness". In other words, the actual brightness corresponding to "r=200, g=200, b=200" by default is twice the actual brightness corresponding to "r=100, g=100, b=100". However, this is not the case for most display devices, for which the actual brightness corresponding to "r=200, g=200, b=200" is more than twice the actual brightness corresponding to "r=100, g=100, b=100". The relationship between the actual display brightness value corresponding to 256 hardware brightness levels and the rgb value is often a power function relationship, and in a few cases, a more complex curve relationship, such as an S-shaped curve. Such a setting is beneficial for highlighting more brightness levels when presenting images, but is not conducive to accurately controlling the presentation brightness of visual stimuli.

[0087] Therefore, the system cannot use the default settings of the display device to present visual stimuli. To improve the scope of application and accuracy, the system uses a segmented power function to evaluate the correspondence between hardware brightness levels and actual brightness.

[0088] After periodic measurement and evaluation, the functional relationship between "theoretical brightness value of the visual stimulus required to be presented when using only any one of the display primary colors" and "the required hardware brightness level value" can be obtained or updated. On this basis, the theoretical brightness value required to be presented on each pixel point of the visual stimulus generated by the visual stimulus generation module can be converted into the required hardware brightness level value and accurately presented.

[0089] The specific working steps of the color brightness evaluation and conversion unit are as follows:

[0090] S3-1, using any one of the display primary colors, in single-color display mode, according to the hardware brightness level indicated by the display device bit depth, sequentially evaluate and record the actual screen brightness at each hardware brightness level;

[0091] S3-2, use the following formula to fit the evaluation data to obtain the fitting parameters and determine the functional relationship between the screen actual brightness and the hardware brightness level:

[0092] ;

[0093] ;

[0094] ;

[0095] Wherein, lum c1 , lum c2 , lum c3respectively are measured screen luminance when one of the display primary colors is used alone; level c1 , level c2 , level c3 is the hardware luminance level; lum c1，max , lum c2，max , lum c3，max respectively are maximum values of measured screen luminance when one of the display primary colors is used alone; a1 c1 , a1 c2 , a1 c3 , a2 c1 , a2 c2 , a2 c3 , b1 c1 , b1 c2 , b1 c3 , BP c1 , BP c2 , BP c3 are fitting parameters; min(·) is the minimum function; max(·) is the maximum function;

[0096] S3-3, when presenting the color visual stimulus, according to the first color and the second color, the proportional relationship between the display primary colors, and the luminance of the first color and the second color required to be presented on each pixel point of the color visual stimulus transmitted by the visual stimulus generation module, determine the luminance of each color of the display primary colors required to be presented, the specific formula is as follows:

[0097] ;

[0098] ;

[0099] ;

[0100] wherein lum(x,y) c1 , lum(x,y) c2 and lum(x,y) c3 represent the luminance of the point with coordinates (x, y) on the color visual stimulus image, which respectively corresponds to the three colors c1, c2 and c3 of the display primary colors; l(x,y) color1 and l(x,y) color2 represent the luminance of the point with coordinates (x, y) on the color visual stimulus image, which respectively corresponds to the first color color1 and the second color color2 required to be distinguished; Ratio color1，c1 , Ratio color1，c2 and Ratio color1，c3Ratio represents the proportion of brightness of each of the three primary colors c1, c2, and c3 in the mixed light of color1. color2，c1 Ratio color2，c2 With Ratio color2，c3 This indicates the brightness proportions of c1, c2, and c3 in the mixed light of the second color color2 when the three primary colors c1, c2, and c3 are mixed.

[0101] S3-4. Based on the functional relationship between the actual screen brightness and the hardware brightness level obtained in S3-2, calculate lum(x,y) obtained in S3-3. c1 lum(x,y) c2 lum(x,y) c3 The hardware brightness level that should be used when converting to actual display, corresponding to the three primary colors of the display. c1 level c2 with level c3 Then, according to the principle of rounding, the level is... c1 level c2 with level c3 Converted to the level closest to the theoretical value for display devices , c1 level , c2 with level , c3 ,Right now

[0102] ;

[0103] ;

[0104] ;

[0105] Among them, level c1 level c2 with level c3 This refers to the theoretical hardware brightness level that should be used when presenting colored visual stimuli, calculated based on the formula in S3-2. , c1 level , c2 with level , c3 It is the actual hardware brightness level after conversion, which is close to the theoretical requirement.

[0106] S3-5, the difference between the hardware brightness theoretical level that should be used when presenting the color visual stimulus and the hardware brightness actual level that is actually applied after conversion, if the absolute value of the difference between the hardware brightness theoretical level and the hardware brightness actual level exceeds 0.10 when displaying any one of the three primary colors, prompting the data recording and analysis module that the color visual stimulus presentation is inaccurate, and marking the test as "abnormal" when presenting the color visual stimulus.

[0107] It should be noted that the actual hardware brightness level that should be used when presenting according to the formula in S3-2 c1 , level c2 and level c3 , are often non-integers, but the actual hardware brightness level used by the display device must be a positive integer. Therefore, in actual operation, rounding is usually used to obtain level , c1 , level , c2 and level , c3 . From this point of view, there is often a certain deviation between the actual brightness and the theoretical calculation value. To effectively reduce the deviation, the display depth of the display device should be more than 10 bits, the higher the better. However, it should be noted that if the first color and the second color are not the display three primary colors of the display device, but other colors mixed and adjusted by the display three primary colors according to a certain proportion, the probability and degree of deviation will greatly increase in the above rounding process. Therefore, S3-5 checks if the deviation of any one of the three primary colors exceeds 0.10, and determines that the stimulus presentation is inaccurate, and marks the test as "abnormal" when presenting the visual stimulus, to facilitate subsequent data analysis and processing.

[0108] After the visual stimulus is generated, it can be presented to the measured individual, and after obtaining the recognition of the measured individual to the stimulus, the next stimulus is presented. This cycle continues until all tests are completed. During the measurement process, the flow control module continuously adjusts the color contrast of the visual stimulus (i.e., the difficulty level of the stimulus). The specific steps are as follows:

[0109] S1-1, if the current test is the first test, the color contrast of the color visual stimulus uses a first value, and the preferred first value is 0.50;

[0110] S1-2, if the result of the individual being measured identifying the color vision stimulus in the previous test is correct, then in the next test, the color contrast of the color vision stimulus is reduced by 1 minimum change unit; if the result of the previous test is incorrect, then in the next test, the color contrast of the color vision stimulus is increased by the first specified number of minimum change units; wherein the first specified number is a positive integer greater than 1, and preferably, the first specified number is 3;

[0111] S1-3, if the number of tests presented to the individual being measured has reached the set maximum test amount, or the color contrast of the color vision stimulus presented to the individual being measured repeatedly fluctuates within the first specified range, or the color contrast of the color vision stimulus has reached the upper and lower limits of the measured color contrast range for 3 consecutive times or a total of 5 times, the test is terminated; preferably, the first specified range is 5 contrast minimum change units.

[0112] It should be noted that due to the hardware limitations of the display device, the actual measurable color contrast has upper and lower limits. If the function of the individual being measured is too good or too poor, exceeding the measurable range of the system, the color contrast adjusted by the process control module will always fluctuate around the upper and lower limits of the measured color contrast range, such as the case mentioned in S1-3, "the color contrast of the color vision stimulus has reached the upper and lower limits of the measured color contrast range for 3 consecutive times or a total of 5 times", so at this time, continuing to measure has no meaning and should be terminated in time.

[0113] Figure 3 Part of the test process is shown. The black or red circles in the figure represent each test, the horizontal coordinate represents the order position of the test in all tests, and the vertical coordinate represents the color contrast level corresponding to the stimulus presented in the test. The difference between adjacent color contrast levels on the vertical coordinate is 2 dB. The "√" above and "×" below the circle in the figure represent the identification of the individual being measured in the test. From the figure, it can be seen that when the individual being measured identifies correctly (i.e. "√"), the difficulty level in the next test is increased by 1 level, i.e. the color contrast level is reduced by 1 level (for example, reduced by 2 dB based on 0.200, to 0.200 / 10^(2 / 20) = 0.158); when the individual being measured identifies incorrectly (i.e. "×"), the difficulty level in the next test is reduced by 3 levels, i.e. the color contrast level is increased by 3 levels (for example, increased by 2*3 = 6 dB based on 0.200, to 0.200*10^(2*3 / 20) = 0.0400).

[0114] The aforementioned process control rules inevitably lead to a phenomenon: if the performance of the measured individual is stable and unaffected by any non-sensory factors (e.g., fatigue, proficiency, rewards, or penalties), and the testing volume is sufficiently large, the color contrast presented to the measured individual in the later stages of the test will inevitably fluctuate around a certain level (see reference...). Figure 3 (The situation after the 14th trial). Even if there are occasional deviations from this level (see reference). Figure 3 In the case of the 30th attempt, the process rules mentioned above will also be applied back (see reference). Figure 3 (The situation in trials 31-38). This specific level is actually the true functional level of the individual being measured. For example, Figure 3 The true level of the measured individual should be between 3 and 6 in color contrast.

[0115] therefore, Figure 3 The entire testing process can be divided into two phases. Phase one begins at the start of the test (the first trial) and continues until the individual's recognition of the stimulus first changes (the 17th trial). All subsequent phases fall under phase two. In phase one, the stimulus difficulty level is gradually adjusted from its initial level to a level close to the individual's actual functional level; this is the preparation phase for obtaining valid measurement data. In phase two, the stimulus difficulty level fluctuates around the individual's actual functional level; this is the phase where valid measurement data is actually obtained.

[0116] Theoretically, it can be predicted that during Phase Two, when the presented color contrast level reaches the true level of the measured individual, the following relationship should exist:

[0117] ;

[0118] in, It represents the probability that the measured individual can correctly perceive a stimulus when the color contrast level reaches the individual's true level. It represents the degree to which the color contrast level decreases in the next test after the measured individual has correctly perceived and responded to the measurement. It represents the probability that the measured individual fails to perceive the stimulus correctly when the color contrast level reaches the individual's true level. It represents the degree to which the color contrast level increases in the next test when the measured individual fails to perceive and respond correctly.

[0119] In combination with the aforementioned rules, "if the result of the color vision stimulus recognition of the measured individual is correct in one test, then the color contrast is reduced by one minimum change unit in the next test; if the result of the color vision stimulus recognition is incorrect, then the color contrast is increased by the first specified number (n) of minimum change units in the next test", the above formula can be derived as p correct = n x p incorrect , according to the established fact that p correct + p incorrect = 100%, the above formula can be derived as p correct = n / ( n + 1). Specifically, when n is 2, p correct = 66.7%; when n is 3, p correct = 75.0%; when n is 4, p correct = 80.0%; and when n is 5, p correct = 83.3%. Therefore, in theory, when n takes different values and is combined with sufficient test quantity, the color resolution threshold at a specific resolution accuracy can be specified by the above flow control method.

[0120] Of course, due to the limitations of measurement accuracy (minimum change unit of color contrast) and various errors, it is difficult to exactly reach the real level of the measured individual in the actual measurement of the presented color contrast level of the stimulus, and generally there is repeated fluctuation around the real level. Therefore, in the actual measurement, statistical methods can be used to take the arithmetic mean of the contrast corresponding to all data points (represented by a red "X" in Figure 3 ) "from correct recognition to incorrect recognition" and data points (represented by a red "√" in Figure 3 ) "from incorrect recognition to correct recognition" in the fluctuation process, so as to infer the real level of the measured individual. According to statistical laws, the more the above data points, the closer the arithmetic mean of the contrast corresponding to these data points to the real level of the measured individual. That is, the larger the test quantity, the higher the accuracy of the analysis result.

[0121] In summary, the above process control method, data analysis rule and sufficient test quantity can ensure the accuracy of the measurement result. The process control method can ensure the positioning of the test result on the S-shaped measurement curve in theory, and the data analysis rule and sufficient test quantity can ensure that the actual operation / analysis result approaches the theoretical value in statistics, meeting the operational requirements of practical applications.

[0122] It is worth mentioning that the control of measurement accuracy in the system can be achieved by adjusting the minimum change unit of color contrast (i.e., the difference between adjacent levels of stimulus intensity), which is not directly related to the process control method, data analysis rule and test quantity. Therefore, the control of measurement accuracy and the accuracy of measurement result in the system are independent of each other and separated from each other.

[0123] In the data recording and analysis module, the specific steps of analyzing and determining the color discrimination threshold value include:

[0124] S2-1, based on the recorded reaction data, listing the color contrast used in each test that is completed normally, and the correct / incorrect situation of the color vision stimulus recognized by the measured individual;

[0125] S2-2, based on the list sorted out in S2-1, selecting the color contrast where the change trend of the color contrast in the measurement process changes, and all of them are recorded as C cri ;

[0126] S2-3, if the number of C cri is less than the second specified number, the analysis is ended and a prompt "threshold value cannot be determined, should be re-measured" is given; otherwise, step S2-4 is entered, and the preferred second specified number is 8;

[0127] S2-4, if the difference between the maximum value and the minimum value of all C cri is not more than the third specified number of contrast minimum change units, the reciprocal of the arithmetic mean of all C cri is determined as the color discrimination threshold value of the measured individual for the first color and the second color; otherwise, step S2-5 is entered, and the preferred third specified number is 5;

[0128] S2-5, among all C cri , according to the time order of occurrence, the first 3 or the first 4 C cri are removed, so that the number of remaining C cri is even, and then the reciprocal of the arithmetic mean of all remaining C cri is taken, and the result is the color discrimination threshold value of the measured individual for the first color and the second color.

[0129] C cri mentioned in S2-2, i.e.,​ Color contrast at the middle red circle. In addition, the C cri The analysis method of taking the arithmetic mean has been described in the foregoing. However, in actual operation, due to the unfamiliarity of the measured individual with the measurement method and process and possible operation errors, the first several C cri , are all lower than the subsequent C cri . Therefore, under the premise of ensuring that there are sufficient C cri and the difference between C cri , the first several C cri may be eliminated in S2-5 to improve the accuracy of the analysis results. In addition, the purpose of "eliminating the first 3 or the first 4 C cri , so that the number of remaining C cri is even" is also to ensure that the number of data points that "change from correct identification to incorrect identification" and the number of data points that "change from incorrect identification to correct identification" in the remaining C cri are the same, so as to provide the accuracy of the analysis results.

[0130] Based on the step descriptions of S2-1 to S2-5, it can be understood that if, during the measurement process, the C cri always fluctuate within the first specified range and have accumulated to the fourth specified number, the test can be terminated in advance even if the current test number has not reached the maximum test amount, and the existing C cri are used to calculate the color discrimination threshold of the measured individual at the specified correct identification rate. Generally, the value of the fourth specified number is in the range of 6 to 20. Preferably, the fourth specified number is 8.

[0131] It should be noted that the test is terminated in advance under the above conditions, which in essence effectively shortens the measurement time on the basis of ensuring the reliability of the measurement results. Therefore, when the measured individual is an animal that cannot effectively communicate, the above setting helps to complete the test as soon as possible on the basis of ensuring the effectiveness of the measurement.

[0132] In addition, it has been mentioned above that if the first color and the second color are not the display tristimulus colors of the display device, but other colors mixed and adjusted by the display tristimulus colors in a certain proportion, the probability and degree of a larger deviation of the color of the stimulus found by S3-5 verification during the generation and presentation of the color visual stimulus will be greatly increased, at this time, it is likely that a situation will occur: although the maximum test amount is completed, due to too many test times being marked as "abnormal" (for example, the number is not less than 10% of all test times), according to the operation of S2-1 to S2-5, the result cannot be normally obtained. Therefore, in the above case, the data recording and analysis module will take another method to calculate the color resolution threshold at the specified resolution accuracy based on the existing data. The specific method is as follows:

[0133] List all the color contrast of the test times that are normally completed, and according to the correct / incorrect identification of the measured individual in these test times, calculate the correct rate of the measured individual in distinguishing the color visual stimulus under the above color contrast, and then find the color contrast with a resolution accuracy greater than the specified accuracy and closest to the specified accuracy, and the color contrast with a resolution accuracy less than the specified accuracy and closest to the specified accuracy, and use linear interpolation to calculate the color contrast under the specified accuracy, which is the color resolution threshold of the measured individual in distinguishing the first color and the second color.

[0134] For example, if the correct identification rate of the measured individual under the color contrast level 5 is 100%, the correct identification rate under the color contrast level 6 is 80%, the correct identification rate under the color contrast level 7 is 70%, the correct identification rate under the color contrast level 8 is 60%, and the correct identification rate under the color contrast level 9 is 40%. Then it can be determined that the color contrast level corresponding to the resolution threshold of the correct identification rate of 75% should be between level 6 and level 7. At this time, using linear interpolation, it can be calculated that the color contrast level corresponding to the correct identification rate of 75% should be level 6.5.

[0135] Finally, optionally, considering the concept of color resolution of the first color and the second color, the relative resolution between the two colors is expressed, which includes "resolving the second color from the first color" and "resolving the first color from the second color". Therefore, the first color and the second color can be designated as the background color alternately and measured twice. That is, the first time, the first color is designated as the background, and the ability to "resolve the second color from the first color" is measured; the second time, the second color is designated as the background, and the ability to "resolve the first color from the second color" is measured. The results of the two measurements are finally taken as the arithmetic mean to determine the color resolution threshold of the measured individual in distinguishing the first color and the second color.

[0136] The above merely illustrates the specific embodiments of the present application, but the technical features of the present application are not limited thereto. Any simple change, equivalent replacement or modification, etc. made on the basis of the present application for realizing basically the same technical effects, are all included in the protection scope of the present application.

Claims

1. A system for measuring color discrimination, comprising: The application comprises: a parameter acquisition module, which acquires measurement parameters, including the minimum change unit of color contrast for distinguishing between a first color and a second color, and the maximum test amount; a visual stimulus generation module, which generates color visual stimuli for measurement based on the parameters acquired by the parameter acquisition module, system built-in parameters, and color contrast delivered by the process control module; a human-computer interaction module, which presents the generated background and color visual stimuli to the measured individual, and acquires the correct / incorrect identification of the color visual stimuli by the measured individual; a process control module, which continuously adjusts the color contrast of the color visual stimuli based on the reaction of the measured individual to the color visual stimuli, until the identification of the color visual stimuli by the measured individual meets the specified requirements; a data recording and analysis module, which records the color contrast of all color visual stimuli in the measurement process and the reaction data of the measured individual, and analyzes and determines the color discrimination threshold of the first color and the second color under the specified correct identification rate.

2. A system for measuring color discrimination according to claim 1, characterized in that: The minimum change unit of the color contrast ranges from 0.5 to 6.0 dB and gradually decreases with the measurement process.

3. The system for measuring color discrimination according to claim 1, wherein: The parameter acquisition module also needs to acquire parameters related to the properties of the visual stimuli, including the size of the visual stimuli, the presentation time, and the auxiliary features related to the identification of the visual stimuli, and there are two or more options for the properties of the visual stimuli in the test for the measured individual to identify. The size of the visual stimuli is indicated by the diameter, and the diameter size ranges from 2.5 to 6.0 degrees of visual angle. The presentation time of the visual stimuli ranges from 1.0 to 5.0 seconds. The auxiliary features related to the identification of the visual stimuli are shape, orientation, or direction.

4. The system for measuring color discrimination according to claim 1, wherein: The first color and the second color for distinguishing are display primary colors of a display device, or other colors mixed and adjusted from display primary colors in proportion.

5. The system for measuring color discrimination according to claim 1, wherein: The color visual stimuli are mixed from the first color and the second color and presented on a uniform background composed of the first color. The brightness of the color visual stimuli and the background is exactly the same, and the identification difficulty of the color visual stimuli is indicated by the color contrast C of the color visual stimuli. The color visual stimuli are graphics with specific shape features or simple meanings, and should meet the following requirements: ； ； wherein C is the chromatic contrast of the color vision stimulus; l mean，color1 represents the luminance of the background composed of the first color; l pattern，color1 represents the luminance in the color vision stimulus corresponding to the first color; l pattern，color2 represents the luminance in the color vision stimulus corresponding to the second color.

6. The system for measuring color discrimination according to claim 1, wherein: In the process control module, the specific steps for adjusting the color contrast of the color visual stimuli are as follows: S1-1, if the current trial is the first trial, the color contrast of the color visual stimuli uses the first value; S1-2, if the result of the identification of the color visual stimuli by the measured individual in the previous trial is correct, the color contrast of the color visual stimuli in the next trial is reduced by 1 minimum change unit; if the identification result in the previous trial is incorrect, the color contrast of the color visual stimuli in the next trial is increased by the first specified number of minimum change units; wherein the first specified number is a positive integer greater than 1. S1-3, if the number of tests presented to the measured individual has reached the set maximum test amount, or the color contrast of the color visual stimulus presented to the measured individual repeatedly fluctuates within the first specified range, or the color contrast of the color visual stimulus has reached the upper and lower limits of the measured color contrast range for 3 times in succession or 5 times in total, then terminate the test.

7. A system for measuring color discrimination according to claim 6, characterized in that: In the data recording and analysis module, the specific step of analyzing to determine the color resolution threshold value comprises: S2-1, based on the recorded reaction data, list the color contrast used in each test that is completed normally, and the correct / incorrect condition of the color visual stimulus recognized by the measured individual; S2-2, based on the list sorted out in S2-1, select the color contrast at which the change trend of the color contrast in the measurement process changes, and all mark as C cri ; S2-3, if the number of C cri is less than a second specified number, then end the analysis and prompt "Threshold cannot be determined, re-measure"; otherwise, proceed to step S2-4. S2-4, if the difference between the maximum value and the minimum value of the C cri values does not exceed a third specified number of color contrast minimum change units, then the inverse of the arithmetic mean of all C cri values is determined to be the color discrimination threshold of the measured individual for the first color and the second color; otherwise, proceed to S2-5. S2-5, in all C cri , the first 3 or the first 4 C cri , so that the number of remaining C cri is even, then take the reciprocal of the arithmetic mean of all remaining C cri , the result is the color resolution threshold of the measured individual for the first color and the second color.

8. A system for measuring color discrimination according to claim 7, characterized in that: The color brightness evaluation and conversion unit in the human-computer interaction module regularly evaluates the brightness of the screen when any one of the three primary colors is presented by the display device, and converts the theoretical brightness of the first color and the second color required to be presented on each pixel point of the color visual stimulus into the closest real application hardware brightness actual level closest to the theoretical requirement; The specific working steps of the color brightness evaluation and conversion unit are as follows: S3-1, using any one of the three primary colors displayed, in the single-color display mode, according to the hardware brightness level indicated by the display device bit depth, the actual brightness of the screen under each hardware brightness level is evaluated and recorded in sequence; S3-2, use the following formula to fit the evaluation data to obtain the fitting parameters and determine the functional relationship between the screen actual brightness and the hardware brightness level: ； ； ； wherein lum c1 , lum c2 , lum c3 are measured screen luminances when using one of the display primary colors alone; level c1 , level c2 , level c3 are hardware luminance levels; lum c1，max , lum c2，max , lum c3，max are maximum values of measured screen luminances when using one of the display primary colors alone; a1 c1 , a1 c2 , a1 c3 , a2 c1 , a2 c2 , a2 c3 , b1 c1 , b1 c2 , b1 c3 , BP c1 , BP c2 , BP c3 are fitting parameters; min(·) is a minimum function; max(·) is a maximum function; S3-3, when presenting the color visual stimulus, according to the proportional relationship between the first color, the second color and the three primary colors displayed, and the brightness of the first color and the second color required to be presented on each pixel point of the color visual stimulus transmitted by the visual stimulus generation module, the brightness of each color required to be presented in the three primary colors displayed is determined, and the specific formula is as follows: ； ； ； wherein lum(x, y) c1 , lum(x, y) c2 , lum(x, y) c3 denote the luminance of the point with coordinates (x, y) on the color vision stimulus image, which respectively corresponds to the luminance of the three colors cl, c2 and c3 in the display tricolor; l(x, y) color1 , l(x, y) color2 denote the luminance of the point with coordinates (x, y) on the color vision stimulus image, which respectively corresponds to the luminance of the first color colorl and the second color color2 to be distinguished; Ratio color1，c1 , Ratio color1，c2 , Ratio color1，c3 denote the proportion of the luminance of cl, c2 and c3 in the mixed light of the first color colorl when the first color colorl is mixed and adjusted using the display tricolor cl, c2 and c3; Ratio color2，c1 , Ratio color2，c2 , Ratio color2，c3 denote the proportion of the luminance of cl, c2 and c3 in the mixed light of the second color color2 when the second color color2 is mixed and adjusted using the display tricolor cl, c2 and c3; S3-4. Based on the function relationship between the actual screen luminance and the hardware luminance level obtained in S3-2, convert the lum(x, y) obtained in S3-3 into the hardware luminance level level c1 corresponding to the display primary colors that should be used at the actual presentation c2 c3 c1 c2 c3 c1 c2 c3 , c1 , c2 , c3 i.e.​​​​​​​​​​ ； ； ； wherein level c1 , level c2 and level c3 are the hardware luminance theoretical levels that should be used when presenting the color visual stimuli, calculated according to the formula in S3-2, level , c1 , level , c2 and level , c3 are the hardware luminance actual levels applied after the conversion. S3-5, calculate the difference between the theoretical level of the hardware brightness that should be used when presenting the color visual stimulus and the actual level of the hardware brightness actually used after conversion, if the absolute value of the difference between the hardware brightness theoretical level and the hardware brightness actual level of any one of the three primary colors displayed exceeds 0.10, then prompt the data recording and analysis module that the color visual stimulus presentation is inaccurate, and mark the test number presenting the color visual stimulus as "abnormal".

9. A system for measuring color discrimination according to claim 8, characterized in that: In the data recording and analysis module, the step of analyzing to determine the color resolution threshold value further comprises: Before performing S2-1, first determine the number of test numbers marked as "abnormal", if the number is less than 10% of the total number of tests, then perform S2-1; If the number is greater than or equal to 10% of all test times, list all color contrast appearing in normally completed test times, and according to the correct / incorrect condition of the measured individual in these test times, calculate the correct rate of the measured individual in distinguishing color visual stimuli under the color contrast condition, and then find the color contrast with correct rate greater than the specified correct rate and closest to the specified correct rate, and the color contrast with correct rate less than the specified correct rate and closest to the specified correct rate, and use linear interpolation to calculate the color contrast under the specified correct rate, which is the color discrimination threshold of the measured individual in distinguishing the first color and the second color.

10. The system for measuring color discrimination according to claim 7, wherein: In step S1-3, the color contrast presented to the measured individual repeatedly fluctuates within a first specified range, specifically: taking the last obtained C cri as a reference, a fourth specified number of C cri have been cumulatively obtained within the first specified range, the fourth specified number being in the range of 6 to 20.

Images