JP3389678B2 - Color measuring device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color measuring device for measuring an object color and displaying the measurement result.

[0002]

2. Description of the Related Art An apparatus for measuring the color of an object and expressing it objectively is conventionally provided as a colorimeter or a color difference meter. FIG. 17 shows an example thereof, in which the measurement surface 10 of the target object is illuminated by using a light source 11 which has a filter (not shown) and outputs irradiation light of a predetermined wavelength, and the reflected light is photographed by a television camera 12. The RGB image signal is sent to the image processing device 30. The image processing device 30 inputs the RGB image signals through the image signal interface 31, and the image processing unit 32 performs numerical conversion of these RGB image signals to obtain C
The XYZ color specification values of the IE standard and other L ^* a ^* b ^* color specification values are obtained and the data are displayed on the monitor 13.
At this time, the image processing unit 32 is connected to a white calibration data memory 33 for registering and storing the data of the white standard plate which is obtained in advance.
Uses the white calibration data registered in the white calibration data memory 33 to calibrate the measurement data.

FIG. 18 shows a flow of operation in the above device. That is, first, in step 501, the white standard plate is measured using the light source 11 and the television camera 12, and in step 502, the measured value is stored as white calibration data in the white calibration data memory 33 in the image processing apparatus 30. Be registered with. Next, in step 503, the actual object is measured, and the reflected light of the object is photographed using the light source 11 and the television camera 12. Then, in step 504, the RGB image signals from the television camera 12 are compared using the previously registered white calibration data,
The change with time such as the brightness of the light source is calibrated.

The RGB values thus calibrated are converted into XYZ color specification values in step 505, and in step 506.
In, the XYZ color specification values are further converted into L ^* a ^* b ^* color specification values. After that, in step 507, the above XYZ is performed.
The colorimetric values and the L ^* a ^* b ^* colorimetric values are displayed on the monitor 13.

However, when the color is divided into three elements of lightness, saturation, and hue, and the difference appears, the above-mentioned conventional apparatus only calibrates with a white standard plate, so that the light source or Although the change with time of the brightness component of the television camera, that is, the brightness is corrected, the change with time of the color such as the change of the wavelength component of the light source and the change of the filter characteristic is not corrected. Therefore, there is a problem that the measurement result includes an error.

Further, in the conversion from RGB values to XYZ values, conventionally, the following conversion formulas based on the values of the main wavelengths of the three primary colors such as RGB, that is, the peak wavelength on the spectral characteristic have been used. There is. X = 0.6067R + 0.1736G + 0.2001B Y = 0.2988R + 0.5868G + 0.1144B Z = 0.0661G + 1.1150B

However, since all hues are converted by one fixed conversion formula, there is a problem that even if a certain color can be accurately converted, an error occurs in another color. In reality, it is not possible to expect highly accurate conversion because errors occur due to differences in the optical instruments that make up the measuring device, such as errors in the camera sensitivity or spectral characteristics. Therefore, in view of the above-mentioned conventional problems, it is an object of the present invention to provide a color measuring device in which not only lightness but also other elements are appropriately corrected and a highly accurate measurement display is performed.

[0008]

Therefore, the present invention is based on FIG.
Illuminate an object with illumination light of a specified wavelength , as shown in
Equipped with a light source that captures images of objects illuminated by the light source
The image signal output means 1 for outputting the RGB image signal of the photographed image of the object and the white standard plate whose colorimetric value is known are
Illuminating with a light source and shooting with an image signal output means
R based on the RGB image signal from the image signal output means
The GB value and the known colorimetric value of the white standard plate are used as white calibration data.
White calibration data generating means 4 for storing the same and a plurality of hues
Light source with multiple colored standard plates with known colorimetric values
Image by illuminating with
RGB values based on RGB image signals from the image signal output means
And the known colorimetric value of the colored standard plate as the color calibration data.
Colored calibration data generation means 5 to be stored in memory and colored calibration
Depending on the color value of the data, the color area of the color system can be
Each area is divided by a dividing line
The above-mentioned colored calibration data and white calibration data corresponding to two areas.
Data from 3 points including data, from RGB value to color value
Conversion parameter calculation means 6 for calculating the conversion parameter of the conversion equation of, and a measurement target object illuminated by the light source.
By photographing the fixed surface with the image signal output means,
The RGB image signal from the output means is input and the hue of the measurement surface
According to the conversion parameter calculated by the conversion parameter calculation means.
Conversion formula from RGB values to colorimetric values by selecting a meter
And the RGB image input by the conversion formula
Color value converter for converting RGB values based on signals into color values
And color data based on the color specification values on the display means 3.
It is supposed to be displayed .

[0009]

In addition to the white color calibration data generating means, the color calibration data generating means 5 is provided to prepare color calibration data based on a plurality of color standard plates. The conversion parameter calculation means 6 uses these calibration data to calculate conversion parameters for each hue. Then, in the colorimetric value conversion means 2, the parameter corresponding to the hue is selected from the conversion parameters to perform the colorimetric value conversion. As a result, the change with time of the lightness component such as the light source that illuminates the measurement target is calibrated with the white calibration data. Since the conversion parameters are selected according to the hue and the conversion formula is set independently for each hue, the characteristics of each hue are reflected in the colorimetric values after conversion, and the error due to the hue is eliminated and the wavelength component Is also corrected over time.

[0010]

1 is a block diagram showing a first embodiment of the present invention. Similar to that of FIG. 17, the measurement surface 1 of the target object
0 is a light source 11 having a filter for outputting irradiation light of a predetermined wavelength, and a television camera 1 for photographing reflected light from the measurement surface.
2 is provided, and the RGB image signal from the television camera 12 is sent to the image processing device 20. And the image processing device 2
The measurement result processed by 0 is displayed on the monitor 13.

The image processing apparatus 20 of this embodiment is further provided with a color calibration data memory 24 in addition to the image signal interface 21, the white calibration data memory 23 and the image processing section 22. In the color calibration data memory 24, the color calibration data obtained by measuring the color standard plate in advance is registered. The image processing unit 22 has a memory for color system conversion therein, stores a conversion matrix from the XYZ color system to the L ^* a ^* b ^* color system, and passes through the image signal interface 21. After calibrating the input RGB image signal with each calibration data, the XYZ colorimetric values are calculated, and the calculated values are further converted into L ^* a ^* b ^* colorimetric values and output to the monitor 13. .

FIG. 3 shows a flow of operation in the above device. That is, first, in step 101, the white standard plate is measured using the light source 11 and the television camera 12, and in step 102, the measured values, that is, RGB values are measured.
The values and the known XYZ values are registered in the white calibration data memory 23 in the image processing apparatus 20 as white calibration data. Next, in step 103, the same measurement is performed on the colored standard plate, and in step 104, the measured value is used as the colored calibration data to obtain the regular XYZ of the colored standard plate.
It is registered together with the value in the color calibration data memory 24 in the image processing apparatus.

A plurality of colored standard plates are prepared for each hue, and in step 105, it is checked whether or not all the colored calibration data have been registered for the hue required for the object to be measured. If all the color calibration data have not been registered, the process returns to step 103, and the color standard plates are sequentially replaced to obtain the color calibration data. When all required color calibration data are registered, in step 106, conversion parameters from RGB values to XYZ values for each hue are obtained from the color calibration data. This conversion parameter is also registered in the colored calibration data memory 24. Steps 101 and 10
2 constitutes the white calibration data generating means of the invention, and steps 103 and 104 constitute the coloring calibration data generating means.

In step 106, areas are divided for each hue, and a conversion formula suitable for each area is calculated and set. FIG. 4 shows the position of each color in the chromaticity diagram of the L ^* a ^* b ^* color system. The above-mentioned area division is performed in the coordinate system of this chromaticity diagram. That is, an achromatic "white" represented near a ^* = 0 and b ^* = 0 is centered and each hue is divided into fans.

When the conversion formula is expressed by the general formula X = a1.R + b1.G + c1.B Y = a2.R + b2.G + c2.B Z = a3.R + b3.G + c3.B, three formulas are obtained from the data of one color. Therefore, the conversion parameters of a1 to c3 are 3 from the data of three colors.
The original simultaneous linear equations are obtained, and by solving this, a1
Values of nine conversion parameters of ~ c3 are determined. Therefore, for example, take 3 points for each area such as white, green, yellow,
Based on the RGB values of these three points and the known XYZ values, RGB
A conversion parameter from the value to the XYZ value is obtained.

Details of the calculation of the conversion parameters are shown in FIG.
Shown in. First, in step 201, a white standard plate having a known XYZ value is measured and the RGB values thereof are obtained. Then, in step 202, a standard color plate whose XYZ values are known is measured, and its RGB values are obtained. Each of these steps 201 and 202 is step 1 in FIG.
01 and 102, and steps 103 and 104 are collectively shown. Then, in step 203, using the conversion matrix stored in the memory for color system conversion, the known XYZ values of the colored standard plate are converted into L ^* a ^* b ^* values, and from the a ^* b ^* values, The position of the color in the chromaticity diagram of the L ^* a ^* b ^* color system is obtained.

Then, in step 204, L ^* a
^* b ^{* The} colorimetric chromaticity diagram is "white" based on the position of each color.
It is divided into fan-shaped regions that require (a ^* = 0, b ^* = 0). In step 205, the conversion equations a1 to c3 are obtained by solving the above simultaneous equations from the known XYZ values and RGB values of three points for each of the fan-shaped areas including “white”. Step 106 in FIG. 3 and steps 203 to 205 in FIG. 5 constitute the conversion parameter calculating means of the invention.

After that, returning to FIG. 3, the actual measurement of the object is started. In step 107, the reflected light of the object is photographed using the light source 11 and the television camera 12. Then, in step 108, the RGB image signals from the television camera 12 are compared using the white calibration data previously registered in the white calibration data memory 23 to calibrate the change with time of the lightness component of the light source.

Next, at step 109, the conversion parameter corresponding to the color of the object to be measured is read from the color calibration data memory 24, and the RGB value is X-valued using this.
Converted to YZ color value. As a result, the change with time of the wavelength component in the light source or its filter is corrected.

Then, in step 110, the color system conversion matrix is read from the memory for color system conversion, the XYZ color system values are converted into L ^* a ^* b ^* color system values using this, and further In step 111, the above XYZ color value and L ^* a
^* b ^* Colorimetric values are displayed on the monitor 13. After that, step 107 and subsequent steps are repeated for each new measurement object. Steps 108 to 110 constitute the colorimetric value conversion means of the invention.

In this embodiment, as described above, the calibration data of the white standard plate and the colored standard plate whose values are known in advance are first registered, and the RGB values are calibrated using this data. By updating the data, not only the lightness component but also the wavelength component is included, and the correction corresponding to the change with time is automatically performed. Then, prepare a large number of colored standard plates and set the RGB value of the image signal to X.
When converting to other colorimetric values such as YZ colorimetric values, the area is divided for each hue and the conversion parameter in each area is obtained, and the conversion parameter obtained above is selected according to the hue of the measurement object. Since the RGB values are converted into XYZ values by using the conversion formula, the conversion formula is set independently for each hue, and therefore the characteristics for each hue are reflected in the XYZ values after conversion.
This has the effect of eliminating an error due to hue.

Since the above conversion parameters are obtained from the measured values of the standard plate, the TV camera, the light source,
It also has the effect of automatically correcting errors due to variations in measuring instruments such as filters. The calculated conversion parameters are registered in the color calibration data memory 24, but a separate memory may be provided for the conversion parameters and stored.

Next, a second embodiment of the present invention will be described. This example uses the L ^* a ^* used in the first example ^.
Instead of the b ^* color system, the L ^* u ^* v ^* color system is used for color measurement. In the measuring apparatus shown in FIG. 2, first, the conversion matrix from the XYZ color system to the L ^* u ^* v ^* color system is stored in the color system conversion memory inside the image processing unit 22 of FIG. The monitor 13 displays the XYZ color value and the L ^* u ^* v ^* color value. FIG. 6 shows step 20 in the flow chart of the first embodiment shown in FIG.
The processing of 3 and subsequent steps is shown instead of steps 403, 404, and 405. Other processing will be described with reference to the flowchart of the first embodiment shown in FIG.

In FIG. 6, steps 201 and 202
RG of white standard plate and known standard plate with known XYZ values
After the B value is measured and necessary data is prepared in the calibration data memory, in step 403, the known XYZ of the colored standard plate is determined.
Converts the value the L ^* u ^* v ^* value, L from the u ^* v ^* value ^*
Find the position of the color in the chromaticity diagram of the u ^* v ^* color system.
In step 404, the L ^* u ^* v ^* colorimetric chromaticity diagram is divided into each color area requiring “white” based on the position of each color. Then, in step 405, the above simultaneous equations are solved from the known XYZ values and RGB values of the three points for each of the above color regions including “white”, and the conversion parameters a1 to c3.
Is required.

After that, the actual measurement of the object is performed as in the first embodiment. That is, as shown in FIG. 3, in step 107, the reflected light of the object is photographed using the light source 11 and the television camera 12, and in step 108, the television camera 1
The RGB image signal obtained from 2 is calibrated with the white calibration data for the change with time of the lightness component of the light source. In step 109, the change over time of the wavelength component in the light source is corrected with the conversion parameter corresponding to the color of the measurement object, and the RGB value becomes X.
Converted to YZ color value. Then, instead of step 110 of converting to the L ^* u ^* v ^* colorimetric value, the XYZ colorimetric value is L
Converted to ^* u ^* v ^* colorimetric values and finally step 111
Is displayed on the monitor 13 together with the L ^* u ^* v ^* colorimetric value and the XYZ colorimetric value. This embodiment, by storing the L ^* u ^* v ^* transformation matrix to the color system from the XYZ color system in the memory for converting color system as described above, L ^* u ^*
Colors can be processed in the v ^* color system. This also eliminates the measurement error due to the hue, and automatically corrects the change with time such as the brightness component including the wavelength component of the illumination.

Next, a third embodiment of the present invention will be described in which color measurement is processed without conversion of the color system. FIG. 7 shows the processing of step 203 and subsequent steps in the flow chart of the first embodiment shown in FIG. 5 in place of steps 303, 304 and 305. Other processing will be described with reference to the flowchart of the first embodiment shown in FIG.

In FIG. 7, steps 201 and 202
RG of white standard plate and known standard plate with known XYZ values
After the B measurement values are stored in the calibration data memory, step 30
In step 3, the position of the color in the XYZ color system chromaticity diagram is obtained from the known XYZ values of the colored standard plate. Step 304
Then, the XYZ color system chromaticity diagram is based on the position of each color,
It is divided into each color area that requires “white”. Then, in step 405, the above simultaneous equations are solved from the known XYZ values and RGB values of the three points for each of the color areas including “white”, and the conversion parameters a1 to c3 are obtained.

After that, as in the first embodiment, the actual measurement of the object is started, that is, in step 107 as shown in FIG. 3, the reflected light of the object is photographed using the light source 11 and the television camera 12. Then, in step 108, the TV camera 12
The RGB image signal obtained from the above is calibrated with the white calibration data for the change with time of the lightness component of the light source. In step 109, the change over time of the wavelength component in the light source is corrected by the conversion parameter corresponding to the color of the measurement object, and the RGB values become XY.
Converted to Z colorimetric values. Then, step 110 is omitted, and in step 111, the above XYZ color specification values are monitored 1.
Display in 3. In the present embodiment, since the color is processed without performing the color system conversion as described above, a memory for color system conversion is not required and the processing speed is improved. Also by this, it is possible to eliminate the measurement error due to the hue and automatically correct the change with time of the brightness component including the wavelength component of the illumination.

In the above embodiment, the processing operation in the image processing unit 22 is to obtain a color specification value conforming to the standard such as CIE. Therefore, in the case of the first embodiment, for example, the color difference is the lightness. , Saturation, ΔL, Δ decomposed into hue
It can be expressed by C, ΔH, or other things, ΔL ^* , Δa ^* , Δb
Symbols such as ^* and ΔE ^* ab are used. Therefore,
When the measurement result is displayed on the monitor 13, the symbols and the numbers indicating the degrees are displayed in the following manner, for example. ΔL ^* = + 1.3 Δa ^* = − 2.1 Δb ^* = +
0.7 ΔE ^* ab = 2.4

The display method decomposed into lightness, saturation and hue is C
Although it is said that it is close to the human sense in standards such as IE, it is difficult to imagine if you do not fully understand the meaning of symbols. In particular, the color difference perceived by humans is characterized not only by the difference from the reference color but also by the absolute chromaticity value of the measurement object. In particular, regarding the hue difference, the way of feeling is completely different depending on where the absolute chromaticity is on the chromaticity coordinate, and for example, even with the same color difference value, it is felt that the color is strongly reddish or strongly yellowed. In addition, the feeling is different depending on whether the color is close to achromatic or not. In particular, regarding ΔH, which represents a hue difference, even if the degree of deviation can be judged from a numerical value, how many color directions are different, for example, whether it is reddish,
Or it cannot be read from now whether it is shifted in the bluish direction.

Therefore, particularly in expressing the color difference, the measurement result can be more promptly and accurately understood by displaying not by the symbol but by the words which a person can easily intuitively imagine. The display method will be described below as a fourth embodiment. Here, for example, red, blue, white, black,
Try to be expressed using words such as sae and nigori.

In the L ^* a ^* b ^* colorimetric system chromaticity diagram of FIG. 4, first, whether the measured color is close to an achromatic color within approximately φ5 to 10 of the L ^* a ^* b ^* coordinate or not is classified. To do. If it is not close to an achromatic color, as shown in FIG. 8, the color difference vector D of the measured color with respect to the reference color on the chromaticity coordinate is set to the brightness component L in the vertical direction and the central achromatic color axis (0 to L ^* ). To a saturation component C in the radial direction and a hue component H in the rotation direction around the achromatic color axis.

Next, as shown in FIG. 9, it is expressed as follows according to the direction of each vector. First, with regard to the brightness direction, when it is facing white (up), it is white when it is facing white (black), and when it is facing outward (saturation). If it faces inward, it will be nigiri.

Since the hue (rotation) direction is not determined only by the direction of the color difference vector, it is expressed by the following method using its position and size. First, as shown in FIG. 10, the L ^* a ^* b ^* color system chromaticity diagram is divided into representative hues, for example, red, yellow, green, and blue spectral color directions around the origin of the achromatic color. . The names of the dividing lines are red dividing line, yellow dividing line, green dividing line, and blue dividing line, respectively.

Then, as shown in FIG. 11, L ^* a ^* b ^*
The difference between the measured color coordinate position and the reference color coordinate position on the colorimetric chromaticity diagram is defined as a color difference vector D. When the hue component H of the color difference vector D in the rotation direction is taken out, this becomes the hue difference. The division of the hue component vector H extending in the rotational direction represents the color shift.
That is, in the example shown in FIG. 11, since the hue component vector H is directed to the yellow dividing line, it becomes “yellowish”.

Further, as shown in FIG. 12, when the hue component vector in the rotational direction crosses the dividing line, the tint is expressed by the preceding dividing line. That is, in the example of (a) of FIG. 12, since the hue component vector crosses the yellow dividing line toward the green dividing line, it becomes “green”, and in the example of (b) of FIG. Since the tip of the vector is on the yellow dividing line, it is expressed as being “yellowish”.

In this way, the shift expression of the color difference vector in each region on the chromaticity diagram of the L ^* a ^* b ^* color system is shown in FIG.
As shown in. As a modified example, in the above dividing lines, each dividing line may have a width at a certain angle, and those within the range can be regarded as on the dividing line. In this case, when both the measurement color and the reference color are within the range, the tint is expressed by the dividing line on the front side where the hue vector is oriented. That is, as shown in FIG. 14, the reference color is not within the dividing line range α in the example a, so the measured color is regarded as on the dividing line and the tint expression is “yellowish”. In the example of C, since the reference color is within the dividing line range α, the tint expression is “greenish” because its hue vector is toward the green dividing line.

On the other hand, when the measurement color is an achromatic color, the expression of the color difference differs depending on the generation area of the color difference vector. That is, when the color difference vector crosses hues, as shown in FIG. 15, the region is divided in the direction of an intermediate color, for example, orange if it is between red and yellow, instead of the spectral component of the representative color. The hue is expressed by the hue name of the destination. That is, in the example of (a) of FIG. 16, it becomes "greenish", in (b) it becomes "yellowish", and in (c) it becomes "reddish". In the case of this achromatic color, the lightness difference is expressed as usual, but the hue difference and the saturation difference are not classified. When the color difference vector is in the same hue, it is expressed in the same way as when it is not an achromatic color, but when the measured color falls within a certain angle from the line toward the center of the reference color, the hue difference is not expressed. , Only by expressing the saturation difference. That is,
As shown in FIG. 16, since both a and b are in the reference color saturation direction range β, the expression of the saturation difference is used, and from the direction of the saturation vector, in the case of b, “even”, the case of b Then, it is said that it is misaligned.

As described above, the deviation direction of the color difference is expressed in words. Regarding the degree of the color difference, whether the value of the length of each vector L, C, H is used for the display, Alternatively, they can be expressed separately as follows. 0: no difference ± 0.5: almost matched ± 1.0: slightly different ± 1.5: slightly different ± 2.0: significantly different ± 2.5: significantly different ± 3.0: completely different

As described above, in the present embodiment, the deviation direction of the color difference is expressed by a word and the degree thereof is expressed by a numeral or a sensory expression corresponding to the numeral. Therefore, the meaning of the symbol in the standard is not fully understood. Even an amateur can know the details of the color difference at a glance by how much the brightness, hue, saturation, etc. are deviated.

[0041]

As described above, according to the present invention, in the color measuring apparatus for converting the RGB image signal into the predetermined colorimetric value and displaying the color data based on the colorimetric value, in addition to the white calibration data generating means, the color calibration is performed. Data conversion means is provided, and the conversion parameter calculation means calculates the conversion parameter for each hue using the colored calibration data based on a plurality of colored standard plates, and the conversion parameter corresponding to the hue is selected to convert the color value. As a result, not only is the change over time of the lightness component of the light source, etc. calibrated, but the characteristics for each hue are reflected in the converted colorimetric values, and the error due to hue disappears and the wavelength component Is also corrected, and highly accurate color data can be obtained.

Further, based on the magnitude and direction of the vector from the position of the reference color to the position of the measurement color in the color data,
If you display it with words that express sensations such as red and blue, even if you do not fully understand the meaning of the symbols in the color specification, it is clear that they are clear, hue, saturation, etc. The advantage is that you can understand at a glance how much is shifted.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of the present invention.

FIG. 2 is a diagram showing an embodiment of the invention.

FIG. 3 is a flowchart showing an operation in the embodiment.

FIG. 4 is a diagram showing an example of color positions in an L ^* a ^* b ^* color system chromaticity diagram.

FIG. 5 is a flowchart showing details of conversion parameter calculation in the first embodiment.

FIG. 6 is a flowchart showing details of conversion parameter calculation in the second embodiment.

FIG. 7 is a flowchart showing details of conversion parameter calculation of the third embodiment.

FIG. 8 is an explanatory diagram showing color difference vectors.

FIG. 9 is a diagram showing an example of representation by the direction of color difference components.

FIG. 10 is an explanatory diagram showing division of regions by hue.

FIG. 11 is an explanatory diagram showing an expression of tint by a vector of hue difference.

FIG. 12 is an explanatory diagram showing expression of tint by a vector of hue difference.

FIG. 13 is a diagram showing a shift expression of a color difference vector in each region on the L ^* a ^* b ^* color system chromaticity diagram.

FIG. 14 is an explanatory diagram showing a tint expression of a hue difference vector within a dividing line range.

FIG. 15 is an explanatory diagram showing a region division and an expression of tint in an achromatic region.

FIG. 16 is an explanatory diagram showing a tint expression in the same hue in an achromatic region.

FIG. 17 is a diagram showing a conventional example.

FIG. 18 is a flowchart showing an operation in a conventional example.

[Explanation of symbols]

1 Image signal output means 2 Color value conversion means 3 display means 4 White calibration data generation means 5 Colored calibration data generation means 6 conversion parameter calculation means 10 measurement surface 11 light source 12 TV camera 13 monitors 20 Image processing device 21 Image signal interface 22 Image processing unit 23 White calibration data memory 24 color calibration data memory 30 image processing device 31 Image signal interface 32 Image processing unit 33 White calibration data memory D color difference vector L brightness component vector C saturation component vector H hue component vector

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Suzuki 2 Takara-cho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. (56) Reference JP-A-5-93654 (JP, A) JP-A-62- 142239 (JP, A) JP 56-77727 (JP, A) JP 53-60683 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01J 3/00-3 / 52

Claims (5)

(57) [Claims] 1. An object is illuminated with illumination light of a predetermined wavelength.
Equipped with a light source that captures images of objects illuminated by the light source
Then, an image signal output means for outputting an RGB image signal of a captured image of the object and a white standard plate having a known colorimetric value are illuminated by the light source.
By recording with the image signal output means, the image signal output
RGB value and white standard plate based on RGB image signal from step
Stores the known colorimetric values of
Positive data generating means and a plurality of colored markers with known colorimetric values corresponding to a plurality of hues
The reference plate is illuminated by the light source, and the image signal output means
By shooting, the RGB image signal from the image signal output means
The RGB values based on the number and the known colorimetric values of the colored standard plate
Colored calibration data generator to store as calibration data
And the colorimetric value of the colored calibration data, the colorimetric area of the colorimetric system
The area is divided by dividing lines for each of the plurality of hues, and the divided areas are divided.
For each area, the above-mentioned colored calibration of 2 points corresponding to the area
Data and three points of data including the white calibration data
In addition, a conversion parameter calculating means for calculating a conversion parameter of the conversion formula from the RGB value to the color value, and a measurement surface of the object to be measured illuminated by the light source in front of
The image signal is output by photographing with the image signal output means.
The RGB image signal from the means is input, and the hue of the measurement surface is input.
Conversion calculated by the conversion parameter calculation means according to
Select and use parameters to convert RGB values to colorimetric values.
A conversion formula is set, and the input RGB is converted by the conversion formula.
Color value conversion that converts RGB values based on image signals into color values
Based on the colorimetric values converted by the colorimetric value conversion means.
A color measuring device comprising: a display unit for displaying dark color data . 2. The color specification values are position coordinates of the color specification system.
The colorimetric value conversion means changes the measurement color from the position of the reference color.
Display the tint based on the magnitude and direction of the vector to the position.
Display the words that appear on the display means by including them in the color data
Color measuring apparatus according to claim 1, characterized in that letting. Wherein the color system is a color measuring apparatus according to claim 1 or 2, wherein it is the XYZ color system. 4. The color measuring device according to claim 1, wherein the color system is an L * a * b * color system. 5. The color measuring device according to claim 1, wherein the color system is an L * u * v * color system.