JP3854492B2 - Color vision inspection device and color discrimination ability investigation device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a color vision inspection apparatus and a color discrimination ability investigation apparatus .
[0002]
[Prior art]
Since color vision is unique to an individual, there are individual differences, and it is extremely difficult to know how others are perceived, and it is considered that it cannot be quantified.
The most extreme example of the individual difference in color vision is an event called color vision abnormality. In the most extreme case, all colors cannot be distinguished.
[0003]
As a method for inspecting color blindness, the Ishihara color vision test table, in which patterns such as numbers are printed according to color points, was recommended by the 14th International Ophthalmology in 1933 and has been used almost as the only method thereafter.
However, in this inspection method, since the printed matter is viewed with reflected light, it is difficult to ensure illumination conditions in addition to the problem of discoloration of printing ink and discoloration due to weathering of printing paper, so the reliability of the inspection result is not necessarily high. .
In addition, since the inspection checks whether or not the characters can be read from the inspection table, even if qualitative determination is possible, how difficult it is to read, in other words, how much color blindness is. We cannot know quantitatively.
[0004]
Not only that, but a bigger problem with the Ishihara color vision test is that the inspector's privacy is uncertain because the inspector and the inspector face each other. The issue of human rights violations such as job discrimination due to
[0005]
In addition, a strict color vision test is performed by a color matching test using monochromatic light, but this test is not only a large-scale apparatus but also a quantitative test is very difficult.
[0006]
SUMMARY OF THE INVENTION
The purpose of the present invention is to solve the problems of these conventional color vision inspection methods, while ensuring the privacy of the inspected person sufficiently, the reliability of the test results is high, and the color vision abnormality is quantitatively detected. A color vision inspection apparatus capable of knowing the degree is provided.
[0007]
In this application, the color matching test is performed using a computer display having a controlled emission color.
Since this color matching test is performed in an environment where only the subject uses a computer, privacy is ensured. In addition, since the emission color is managed, not only is the test result reliable enough, but a quantitative test result can be obtained by the binary search method, and errors can be eliminated from the test result by inconsistency inspection. Is possible.
[0008]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
First, a color expression method will be described with reference to FIG.
For example, there is a method of specifying a color expression by a standard number as defined in JIS, for example. However, since this method does not allow the whole color to be glimpsed, it was practically used in 1931 by the International Commission on Illumination (CIE: Commission). The “CIE 1931 chromaticity diagram (hereinafter simply referred to as“ chromaticity diagram ”)” based on the “XYZ color system” defined by Internationale de l'Eclairage is generally adopted.
[0009]
FIG. 1 shows a schematic diagram of a “chromaticity diagram”. This diagram expresses chromaticity (hue, saturation) on the xy axis, and expresses lightness on the Y axis (not shown). Similar to a solid. All colors existing in the natural world can be expressed by coordinate values of the chromaticity diagram, and the main wavelength component and saturation of the color can be read from the chromaticity diagram.
[0010]
On the chromaticity diagram, the human visible range has a horseshoe shape 1 as shown in the figure, the upper part is green (G), the lower left part is blue (B), the lower right part is red (R), The central part of the horseshoe shape is white (W), and the outside is black which is an invisible color. In this figure, the numbers written along the horseshoe shape 1 are the wavelengths of the colors expressed in nm.
In FIG. 1, a triangle 2 expressed as “CRT” is a color expression range by a CRT display, and a triangle 3 expressed as “TFT” is a color expression range by a TFT liquid crystal display.
[0011]
Next, the color vision abnormality will be described with reference to FIG.
The vast majority of people need three colors (red, blue, yellow or R, G, B) to represent a color, and such color vision is called three-color vision.
However, there is a color vision that does not require three colors for color expression, and such color vision is called color blindness.
Color vision that can be expressed by only two colors is called two-color color vision, and color vision that can be expressed by only one color is called one-color color vision.
[0012]
The two-color type color vision associated with the chromaticity diagram is shown in FIG.
A color vision abnormality in which a color arranged on a straight line drawn from the convergence point P shown in FIG. 2A cannot be identified is called a first-type two-color color vision (P).
A color vision abnormality in which a color arranged on a straight line drawn from the convergence point D shown in FIG. 2B cannot be identified is called a second type two-color color vision (D).
A color vision abnormality in which a color arranged on a straight line drawn from the convergence point T shown in FIG. 2C cannot be identified is called a third type two-color color vision (T).
Further, even in the case of three-color type color vision, a color vision whose ratio of the three colors is significantly different from normal is called abnormal three-color type color vision, and such color vision is called weak color.
[0013]
These convergence points P, D, and T are called confusion color centers, and P: x = 0.747, y = 0.253, z = 0.000, respectively.
D: x = 1.080, y = −0.080, z = 0.000
T: x = 0.175, y = 0.004, z = 0.821
It has been confirmed that.
[0014]
The invention of the present application displays color and achromatic colors existing on these straight lines called confusion color lines on a display by a computer, and causes the subject to determine whether or not a chromatic color is displayed. Judgment is automatically performed.
The colors on the computer are represented by R, G, B3 colors each having a gradation of 8 bits (256) and a total of 24 bits (16,777,216).
In some graphic computers, R, G, and B colors are expressed by a total of 30 bits (1,073,741,824) with 10-bit (1024) gradations.
The relationship between the color expressed on the computer and the chromaticity diagram is unambiguously defined by the international standard “61966-2-1” of the International Commission on Illumination, and the color on the chromaticity diagram is based on this relationship. Is displayed on the computer.
[0015]
A color vision inspection method and a color vision inspection apparatus according to an embodiment of the present invention will be described with reference to FIG.
FIG. 3 shows a case where the abnormality of the first-type two-color color vision (P) related to the confusion color center P is inspected, and the confusion color passing through the confusion color center P and the white center point C on the chromaticity diagram. A straight line PC is drawn, and among the two points where the confusion color line PC intersects the triangle 2, the point far from the confusion color center P (green) is P1, and the near point (red) is P1 '. .
[0016]
The chromatic colors (green) corresponding to these points P1 are synthesized on a computer and arranged with the achromatic colors (gray) of the same brightness on the CRT display 4, and as shown in FIG. Is displayed.
One of the colors displayed in the rectangles 5 and 6 is always an achromatic color, and both the rectangles 5 and 6 may be displayed in an achromatic color. In the example of FIG. 4, the rectangle 5 is a chromatic color and the rectangle 6 is an achromatic color.
A black line 7 is arranged at the boundary between the two rectangles so that the colors of the rectangle 5 and the rectangle 6 cannot be directly compared.
[0017]
The subject compares the color of the rectangle 5 displayed on the CRT display 4 with the color of the rectangle 6, and clicks the left button of the computer when determining that the colors are different. The means for inputting the judgment result to the computer is not limited to the left button of the mouse, and appropriate input means such as an appropriate key on the keyboard and a dedicated switch can be used. In order to preserve the operation, the operation is concealed by operating the mouse button.
[0018]
When the operation is performed, the computer recognizes that the subject has determined that the color of the rectangle 5 is different from the color of the rectangle 6, and when the operation is not performed within a predetermined time (for example, 2 seconds), the computer The test subject recognizes that the color of the rectangle 5 is not different from the color of the rectangle 6.
The display time of 2 seconds is insufficient for the subject to think and is a time that must be judged intuitively.
[0019]
When the subject performs an operation, the computer determines that the subject has recognized that one of the colors is chromatic.
If the subject does not perform an operation, the computer determines that the subject has recognized that only the achromatic gray color is displayed or that the subject has not been recognized that the chromatic color has been displayed.
[0020]
If the subject's judgment is valid, a more detailed examination is performed by binary search or dichotomizing search. (See “Iwanami Information Science Dictionary” for “Binary Search”)
The binary search is illustrated in FIG. In this description, it is assumed that there is no error in the operation of the subject and that the operation corresponding to his / her own judgment is correctly performed.
In this figure, C and P1 are points C and P1, respectively, existing on the confusion color line CP shown in FIG. Further, the points described as 1, 1/2, 1/4... Are points on the confusion color line CP when the C point is 0 and the P1 point is 1. .
[0021]
When the subject determines that the colors of the points P1 and C are not different, it is not necessary to perform further inspection between the points P1 and C.
When the subject judges that the colors of P1 and C are different, the same inspection is performed for the point P2 located in the middle between the points C-P1.
[0022]
When the subject determines that the color of the point P2 is different from the color of the point C, the same inspection is performed on the point P3 located in the middle of the point P2-C, and thereafter the same inspection is performed in detail.
When the subject determines that the color of the point P2 and the color of the point C are not different, it is not necessary to perform further inspection between the points P2 and C. Instead, the same inspection is performed for the point P6 located in the middle of the points P1-P2.
[0023]
By performing such an inspection, it is determined which point color can finally be determined to be different from the point C. The accuracy can be determined up to 2-n points by n inspections.
Similarly, the same inspection is performed for the point P1 ′ on the first type two-color type color vision (P) with respect to the same convergence point P, and further, the second type two-color type color vision (D) and the confusion about the confusion color center D. A similar test is performed for the third type two-color color vision (T) related to the color center T.
[0024]
The inspection for the first-type two-color color vision (P), the second-type two-color color vision (D), and the third-type two-color color vision (T) is not performed in order but is performed by mixing them appropriately. .
[0025]
If these inspections are performed without error, the minimum number of inspections required when the inspection accuracy is 2-n is (n + 1) × 2 (direction) × 3 (confused color center).
Therefore, as shown in FIG. 5, [n = 4], that is, an inspection result with an accuracy of 1/16 can be obtained by (4 + 1) × 2 × 3 = 30 inspections.
[0026]
The results obtained in this way are quantitative, and the state of color vision can be visually expressed by entering the results in a chromaticity diagram.
Furthermore, the contents of abnormal three-color type color vision can be specifically expressed by entering them on the chromaticity diagram.
[0027]
However, not all test subject operations are correct.
Among the operations of the subject, the judgment content of the subject may not match the judgment content of the computer due to a simple erroneous operation, an operation delay, an oversight or a false operation.
When such an erroneous operation is performed, a contradiction occurs in the operation content.
[0028]
For example, if the subject operates that P5 has been discriminated and does not perform the operation that P3 has been discriminated, there is a contradiction in this operation. In such a case, the entire inspection for P1, P2, P3, P4, and P5 is performed again.
This method is called a contradiction inspection. By adopting this method, the number of inspections increases, but the reliability of the inspection result is remarkably improved.
[0029]
[Application Examples of the Present Invention]
An application embodiment of the present invention will be described with reference to FIG.
In FIG. 6, “M” indicates how far away the color looks different with respect to 25 points in the chromaticity diagram, and is called “MacAdam ellipse”. This ellipse is an exact ellipse and thus has a major axis and a minor axis. Note that this ellipse is actually smaller, and is shown enlarged 10 times for convenience of display.
[0030]
Although humans recognize these colors outside the ellipse as different colors, the color discrimination threshold for discriminating whether they are the same color or different colors has a spread approximately three times that of this ellipse. In other words, if a color that exists within three times the range of each ellipse is used, it is recognized that the same color is used without using the exact same color.
[0031]
As seen in the shape of the ellipse of MacAdam, the color discrimination threshold does not exist only on the confused color line but has an elliptical divergence, in other words, also on a straight line orthogonal to the confused color line. ing.
Therefore, a more accurate inspection result can be obtained by performing the same inspection on the color existing on the straight line perpendicular to the confusion color line at the center point C as in the inspection on the confusion color line.
[0032]
In order to perform this inspection, the operation of the apparatus needs to be regulated.
Therefore, γ correction for correcting the linearity of the display device and brightness adjustment are performed before the start of inspection.
[0033]
In the above embodiments, the case where the CRT is used has been described. The reason is that only the CRT is standardized with respect to the emission color at this stage, and the other display devices LCD, PLD, LED, EL are not standardized. .
However, it goes without saying that these display devices and other display devices can be used in the present invention if the emission color is standardized.
In addition, when a precise inspection result is not required, a non-standard display device can be used.
[0034]
[Usage example of MacAdam ellipse]
As mentioned above, humans recognize that colors that are within the color discrimination threshold that is three times the range of MacAdam's ellipse are the same color, so if each color has a range that is three times that of MacAdam's ellipse, The conditions for colors used in the industrial or expression field are relaxed.
However, although the “MacAdam ellipse” shown in FIG. 6 is only 25, there are, of course, infinite colors existing on the chromaticity diagram, that is, infinite.
[0035]
Therefore, it is difficult to obtain a necessary color discrimination threshold for a certain color and use the result in an industrial or expression field. Conventionally, a color discrimination threshold is obtained by trial and error, which is extremely inefficient.
In addition, the color discrimination threshold obtained in this way is only qualitative and not quantitative, so the result cannot be diverted and must be obtained each time.
[0036]
The method of the present invention can be used to determine this color discrimination threshold and will be briefly described below.
(1) The 24-bit or 30-bit computer data corresponding to O for displaying the central color O on the display is determined.
(2) The computer data of the points Q1 to Q16 at equal intervals (16 in the figure) on a circle Q centered on O is obtained. In this case, the diameter of the circle Q is assumed to be slightly larger than the major axis of the expected “MacAdam ellipse”.
{Circle around (3)} Each of the diameters is treated as a virtual confusion color line to obtain a range E1 to E16 that can be identified by a subject having standard color vision. These ranges are Ellipse according to MacAdam.
[0037]
The binary search applied in the usage example of FIG. 7 will be described with reference to FIG. In this description, it is assumed that there is no error in the operation of the subject and that the operation corresponding to his / her own judgment is correctly performed.
In this figure, O and Q are points O, Q1,... Existing on virtual confusion color lines on arbitrary diameters shown in FIG. In addition, the points described as 1, 1/2, 1/4... Exist on the virtual confusion color line OQ when the O point is 0 and the Q point is 1. It is.
[0038]
(A) shows a case where the subject judges that the color of the point O is different from the color of the point Q. The point R1 and the point R2 are inspected to obtain the point R as the final color distinguishable range.
(B) shows the case where the subject did not judge that the color of the point O and the color of the point Q are different, in which case the color distinguishable range is outside the virtual confusion color line OQ. become. In that case, a point R of OQ = QR1 is determined, and Q-R1 is inspected as points R2 and R3 in the same manner as in (a) to obtain a point R as a final color distinguishable range.
[0039]
Since humans cannot recognize the color difference in the ellipse thus obtained, it is useful when selecting or restricting colors to be used in an industrial field or an expression field such as printing / television.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a chromaticity diagram.
FIG. 2 is an explanatory diagram of abnormal color vision.
FIG. 3 is an explanatory diagram of a color vision test.
FIG. 4 is a display screen example.
FIG. 5 is an explanatory diagram of a binary search method.
FIG. 6 is an explanatory diagram of an ellipse of MacAdam.
FIG. 7 is an explanatory diagram of an application example.
FIG. 8 is an explanatory diagram of a binary search method of an application example.
[Explanation of symbols]
1 Chromaticity diagram curve 2 Color expression range by CRT display 3 Color expression range by TFT liquid crystal display 4 CRT display 5, 6 Rectangular 7 Black line C, O Center points P, D, T Confusion color center M Ellipse Q MacAdam Q Circle E ellipse

Claims (3)

A color display that displays two colors of the same brightness existing on the mixed color line of the two-color type color vision, and two colors existing on the mixed color line of the two-color type color vision displayed on the color display are selected by the binary search method. , input devices, color vision test apparatus consisting of an input computer which controlled by the additive, the two color difference of the displayed. The color vision inspection apparatus according to claim 1 , further comprising: displaying two colors existing on a color line orthogonal to a confusion color line of a two-color type color blind person and determining the color vision ability based on whether or not the two colors are discriminated. . The color to be measured and predicted on the chromaticity diagram around the color to be measured and near the color to be measured MacAdam A binary search method is used to select a color having the same brightness as the measurement target color that exists on each of a plurality of diameters of a circle having a diameter slightly larger than the major axis of the ellipse, and these two colors are additively mixed. A computer that controls the two colors, a color display that displays two colors, and an input device that inputs the difference between the two displayed colors, and obtains a color distinguishable range depending on whether these two colors can be identified. Discriminating ability investigation device.

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