JP3014249B2 - Color image processing equipment - 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 processing for detecting an original object color vector of an object and an illumination light vector of the illumination light from a color vector of each pixel of the object illuminated by the illumination light. More particularly, the present invention relates to a color image processing apparatus that can detect an object color vector and an illumination light vector with high accuracy.

2. Description of the Related Art It is sometimes required to detect an original object color vector of an object from a color vector of each pixel of the object detected by a color image scanner or the like. In such a case, it is necessary to detect the object color vector with high accuracy.

[0003]

2. Description of the Related Art First, a description will be given of a color changing process of a color image as a background of the present invention. In a system for creating an electronic catalog of products using a computer, a configuration is adopted in which a base color image is read by a color image scanner and displayed on a color monitor, and the colors of objects in these color images are changed. Then, the process of completing the catalog and the design is executed.

[0004] In order to perform such a color change processing of a color image with high accuracy, the present applicant has previously filed Japanese Patent Application Laid-Open No. 5-408.
No. 33 (Title of Invention: Color Image Control Method) enables the color of an object in a color image to be changed while preserving the naturalness of the image by using a strict object reflection model. The invention has been disclosed in which the appearance can be changed.

[0005] That is, in the present invention, if the description is made in the RGB color system,

[0006]

(Equation 1)

As shown by the above, the object color vector (Rd, Gd,
Bd) and a coefficient K1; a vector defined by a product of an illumination light vector (Rs, Gs, Bs) and a coefficient K2; and an environmental light vector (Ra, Ga, An object reflection model is derived, in which the color vector (Ro, Go, Bo) of each pixel of the object is expressed according to the addition vector of the vector defined by the product of Ba) and the coefficient value K3. .

When the color of an object in a color image is changed, first, the object color vector (Rd, Gd, B
d) The appropriate values of the illumination light vector (Rs, Gs, Bs) and the environment light vector (Ra, Ga, Ba) are derived. Next, from this state, the color vector (Ro, Go, Bo) of each pixel of the object before the color change is known, and it is possible to solve the ternary simultaneous equation defined by the expression (1). Therefore, the coefficient values K1, K2, and K3 of each pixel of the object are calculated.

Subsequently, the object color vector (Rd, Gd, Bd)
, The illumination light vector (Rs, Gs, Bs) and the environmental light vector (Ra, Ga, Ba) change, so that the object color vector (Rd ', Gd', B
d '), the illumination light vector (Rs', Gs', Bs') and the ambient light vector (Ra', Ga ', Ba') are determined, and the calculated coefficient values K1, K2, K3 are used.

[0010]

(Equation 2)

By calculating the color vector (Ro ', Go', Bo ') of each pixel of the object according to the above, the color vector of each pixel of the object after the color change is determined. . In order to execute the color change processing of a color image according to the present invention, the object color vector (Rd, Gd, Bd) before the color change is performed.
, The illumination light vector (Rs, Gs, Bs) and the environment light vector (Ra, Ga, Ba) must be accurately obtained. In particular, the object color vector (Rd, Gd, Bd) is accurately calculated. It is necessary to seek.

As a method for obtaining the object color vector (Rd, Gd, Bd), conventionally, the operator is required to express the most original color from the color image of the object displayed on the display screen. This was done by letting them select points that were considered For example, by selecting the most appropriate blue from the blue cars displayed on the display screen, the object color vector (Rd, Gd,
Bd) was detected.

[0013]

However, according to such a conventional technique, since the object color vector (Rd, Gd, Bd) is detected by the operator's experience, the object color vector (Rd, Rd, Gd, Bd) is detected. Gd, Bd) cannot be detected accurately. In addition, there is a problem that a load is imposed on the operator.

Against this background, the present applicant has
In Japanese Patent Application No. 5-52055 (title of the present invention: color image processing method and color image processing apparatus), a color vector (Ro, Go, Bo) of each pixel of an object detected by a color image scanner or the like. ), The original object color vector (Rd, Gd, Bd) of the object can be automatically detected, and the illumination light vector (Rs, Gs, Bs) of the illumination light for illuminating the object can also be detected. An invention has been disclosed that enables detection.

That is, in the present invention, if the description is made in terms of the RGB color system,

[0016]

(Equation 3)

First, the chromaticity value (r, g) of the color vector (Ro, Go, Bo) of each pixel of the object is calculated. At this time, the low luminance data and the data of the edge portion are removed because the error increases. As shown in FIG. 12, the chromaticity value (r, g) calculated in this way is the chromaticity value of the object color vector (Rd, Gd, Bd) and the illumination light vector (Rs, Gs, Bs). Then, as shown in FIG. 13, a straight line approximating this chromaticity value distribution is obtained by the least square method or the like, as shown in FIG.

Subsequently, as shown in FIG. 14, from the frequency distribution of the chromaticity values on the straight line, the chromaticity value of the object color vector (Rd, Gd, Bd) positioned as the end point of the straight line and the illumination light vector And the chromaticity value of (Rs, Gs, Bs). here,
The light source characteristics of the illumination light, such as a white light source, are generally known, and it is known which end point has the chromaticity value of the illumination light vector (Rs, Gs, Bs). The chromaticity value of the object color vector (Rd, Gd, Bd) and the chromaticity value of the illumination light vector (Rs, Gs, Bs) are specified.

Subsequently, the detected object color vector (Rd, G
d, Bd), the color vector (Ro,
Go, Bo) and the brightness of a color vector (Ro, Go, Bo) of a pixel of an object having a chromaticity value in the vicinity of the brightness are represented by:

[0020]

(Equation 4)

In accordance with FIG. 15, the average value of these values and the one having the largest value are detected as the brightness of the object color vector (Rd, Gd, Bd), and the detected illumination The brightness of the color vector (Ro, Go, Bo) of the pixel of the object having the chromaticity value of the light vector (Rs, Gs, Bs) and the color vector (Ro, Ro) of each pixel of the object having the chromaticity value in the vicinity thereof Go, Bo) and [Equation 4]
According to the formula, as shown in FIG. 15, these average values,
The one having the largest value among these is detected as the brightness of the illumination light vector (Rs, Gs, Bs).

Subsequently, from the detected chromaticity value (r, g) and the detected brightness L,

[0023]

(Equation 5)

In accordance with the object color vector (Rd, Gd, Bd
) And the illumination light vector (Rs, Gs, Bs). Indeed, according to the invention of the earlier application,
The object color vector (Rd,
Gd, Bd) and the illumination light vector (Rs, Gs, Bs) can be detected with high accuracy.

However, according to this method, the chromaticity values of the color vectors (Ro, Go, Bo) of each pixel of the object are not distributed on a straight line but spread over a wide area as shown in FIG. It happens to be distributed. this is,
Ambient light vectors (Ra, Ga, Ba) exist, and
This is because color misregistration is present in color image scanners, and in addition, low-luminance data or edge data, which may be an error factor, cannot be sufficiently removed or reflect illumination light such as gloss contained in an object image. This is caused by missing parts.

In such a case, the object color vector (Rd, Gd, Bd) and the illumination light vector (Rs, Gs, Bs) cannot be accurately obtained even if the invention of the application is applied.

The present invention has been made in view of the above circumstances. According to the invention of Japanese Patent Application No. 5-52055, a color vector of each pixel of an object detected by a color image scanner or the like is used. Automatically adopts a configuration for automatically detecting the original object color vector of the object and the illumination light vector of the illumination light for illuminating the object, so that these vectors can be detected with high accuracy. A new color image processing apparatus is provided.

[0028]

FIG. 1 and FIG. 2 show the principle configuration of the present invention. A color image processing apparatus 1 according to the present invention, whose principle configuration is illustrated in FIG. 1A, includes a detected color vector storage unit 10, a calculation unit 11, a correction unit 12, a specifying unit 13, and a first detection unit 14. And the second detection means 15
And deriving means 16.

The detected color vector storage means 10 manages the color vector of each pixel of the object detected by a color image scanner or the like. The calculating unit 11 calculates a chromaticity value of a color vector of a pixel of the object stored in the detected color vector storing unit 10. The correcting unit 12 corrects the chromaticity value distribution by adding the chromaticity value of the illumination light vector to the chromaticity value distribution calculated by the calculating unit 11. Identifying means 1
3 specifies an approximation line that approximates the chromaticity value distribution generated by the correction unit 12. The first detector 14 detects the chromaticity value of one or both of the object color vector and the illumination light vector. The second detection unit 15 detects the brightness of one or both of the object color vector and the illumination light vector. The deriving unit 16 derives one or both of the object color vector and the illumination light vector.

The color image processing apparatus 1 of the present invention whose principle configuration is shown in FIG.
And a calculating means 11, a specifying means 13, a first detecting means 14, a second detecting means 15, and a deriving means 16.

The detected color vector storage means 10 manages the color vector of each pixel of the object detected by a color image scanner or the like. The calculating unit 11 calculates a chromaticity value of a color vector of a pixel of the object stored in the detected color vector storing unit 10. The specifying unit 13 specifies an approximation line that approximates the chromaticity value distribution calculated by the calculating unit 11 on condition that the chromaticity value passes through the chromaticity value of the illumination light vector or a chromaticity value in the vicinity thereof. The first detector 14 detects the chromaticity value of one or both of the object color vector and the illumination light vector. The second detection unit 15 detects the brightness of one or both of the object color vector and the illumination light vector. The deriving unit 16 derives one or both of the object color vector and the illumination light vector.

The color image processing apparatus 1 of the present invention, whose principle configuration is shown in FIG. 2, comprises a detected color vector storage means 10, a calculation means 11, a setting means 17, a search means 18, a specifying means 13, The first detecting means 14 and the second detecting means 1
5 and a deriving unit 16.

The detected color vector storage means 10 manages the color vector of each pixel of the object detected by a color image scanner or the like. The calculating unit 11 calculates a chromaticity value of a color vector of a pixel of the object stored in the detected color vector storing unit 10. The setting unit 17 sets a plurality of regions of a specific shape using the chromaticity value of the illumination light vector or a chromaticity value in the vicinity thereof as a rotation center. The search means 18
By evaluating the degree of overlap between each area set by the setting means 17 and the chromaticity value distribution calculated by the calculation means 11, the area having the highest degree of overlap is searched for in these areas. The specifying unit 13 specifies an approximate line that approximates the chromaticity value distribution calculated by the calculating unit 11 from the area searched by the searching unit 18. The first detector 14 detects the chromaticity value of one or both of the object color vector and the illumination light vector. The second detection unit 15 detects the brightness of one or both of the object color vector and the illumination light vector. The deriving unit 16 derives one or both of the object color vector and the illumination light vector.

[0034]

In the color image processing apparatus 1 of the present invention, the principle of which is shown in FIG. 1A, the calculating means 11 calculates the chromaticity values of all the color vectors of the pixel of the object or the chromaticity values of the color vectors. Calculate the chromaticity value of the one with less noise component of
Upon receiving the calculation result, the correction unit 12
By adding the chromaticity value of the illumination light vector or a chromaticity value in the vicinity of the chromaticity value distribution to the calculated chromaticity value distribution, the calculated chromaticity value distribution is corrected. 1
3 specifies an approximate line that approximates the corrected chromaticity value distribution.

In response to the specified result, the first detecting means 1
4 is an approximation line specified by the specifying unit 13 and a correction unit 12
, The chromaticity value of the object color vector / illumination light vector located at the end point of the approximate line is detected from the chromaticity value distribution generated by The brightness of the object color vector / illumination light vector is detected from the color vector of the pixel of the object from which the chromaticity value is calculated (the color vector of the chromaticity value in the vicinity may be considered). In response to the result, the deriving unit 16 determines the chromaticity value detected by the first detecting unit 14 and the second detecting unit 15
Then, an object color vector / illumination light vector is derived and output from the detected brightness.

As described above, in the color image processing apparatus 1 of the present invention whose principle configuration is shown in FIG. 1A, the chromaticity value distribution of the color vector of each pixel of the object is approximated by the approximation line. The chromaticity value of the object color vector / illumination light vector located as the end point is detected, and the brightness of the object color vector / illumination light vector is calculated from the color vector of the pixel of the object from which the chromaticity value was calculated. When adopting a configuration for detecting and detecting an object color vector / illumination light vector from these detection values, a configuration is adopted in which the chromaticity value of the illumination light vector is forcibly added to the chromaticity value distribution. Therefore, it is guaranteed that the approximation line approximating the chromaticity value distribution passes through the chromaticity value of the object color vector, and the object color vector / illumination light vector can be detected with high accuracy.

In the color image processing apparatus 1 of the present invention, the principle of which is shown in FIG. 1B, the calculating means 11 calculates the chromaticity values of all the color vectors of the pixel of the object or the chromaticity values of the color vectors. Calculating the chromaticity value of the noise component having a small noise component, and receiving the calculation result, the specifying means 13 calculates the chromaticity value of the illumination light vector on the condition that the chromaticity value passes through or near the chromaticity value of the illuminating light vector. An approximation line that approximates the chromaticity value distribution calculated by 11 is specified.

In response to the specified result, the first detecting means 1
4 is an approximation line specified by the specifying unit 13 and a calculation unit 11
, The chromaticity value of the object color vector / illumination light vector located at the end point of the approximate line is detected from the chromaticity value distribution calculated by The brightness of the object color vector / illumination light vector is detected from the color vector of the pixel of the object from which the chromaticity value is calculated (the color vector of the chromaticity value in the vicinity may be considered). In response to the result, the deriving unit 16 determines the chromaticity value detected by the first detecting unit 14 and the second detecting unit 15
Then, an object color vector / illumination light vector is derived and output from the detected brightness.

As described above, in the color image processing apparatus 1 of the present invention, whose principle configuration is shown in FIG. 1B, the chromaticity value distribution of the color vector of each pixel of the object is approximated by the approximation line. The chromaticity value of the object color vector / illumination light vector located as the end point is detected, and the brightness of the object color vector / illumination light vector is calculated from the color vector of the pixel of the object from which the chromaticity value was calculated. When adopting a configuration of detecting and detecting an object color vector / illumination light vector from these detection values, an approximation line approximating the chromaticity value distribution forcibly sets the chromaticity value of the illumination light vector. By adopting a configuration of passing, the approximation line is guaranteed to pass the chromaticity value of the object color vector, and the object color vector / illumination light vector can be detected with high accuracy.

In the color image processing apparatus 1 of the present invention whose principle configuration is shown in FIG. 2, the calculating means 11 calculates the chromaticity values of all the color vectors of the pixel of the object or the noise components in the color vectors. The setting unit 17 sets a plurality of regions of a specific shape using the chromaticity value of the illumination light vector or a chromaticity value in the vicinity thereof as a rotation center. Calculation results of the value distribution,
In response to the region setting result by the setting unit 17, the search unit 18 evaluates the degree of overlap between the set region and the calculated chromaticity value distribution, and thereby the highest degree of overlap among the set regions. In response to the search result, the specifying unit 13 specifies an approximate line that approximates the calculated chromaticity value distribution, for example, by specifying the center line of the searched area. I do.

In response to the specified result, the first detecting means 1
4 is an approximation line specified by the specifying unit 13 and a calculation unit 11
, The chromaticity value of the object color vector / illumination light vector located at the end point of the approximate line is detected from the chromaticity value distribution calculated by The brightness of the object color vector / illumination light vector is detected from the color vector of the pixel of the object from which the chromaticity value is calculated (the color vector of the chromaticity value in the vicinity may be considered). In response to the result, the deriving unit 16 determines the chromaticity value detected by the first detecting unit 14 and the second detecting unit 15
Then, an object color vector / illumination light vector is derived and output from the detected brightness.

As described above, in the color image processing apparatus 1 of the present invention whose principle configuration is illustrated in FIG. 2, the chromaticity value distribution of the color vector of each pixel of the object is approximated by the approximation line, so that the end point is obtained. The chromaticity value of the located object color vector / illumination light vector is detected, and the object color vector /
When adopting a configuration in which the brightness of the illumination light vector is detected and the object color vector / illumination light vector is detected from these detected values, an approximation line that approximates the chromaticity value distribution is Since the configuration is adopted in which the chromaticity value is forcibly passed, it is guaranteed that this approximation line passes the chromaticity value of the object color vector, and the object color vector / illumination light vector can be accurately determined. It can be detected.

[0043]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to embodiments. FIG. 3 shows a system configuration of the color image processing apparatus 1 implementing the present invention. In the figure, reference numeral 20 denotes an image input device connected to the color image processing device 1.

The color image processing apparatus 1 includes an image holding memory 21 for holding color image data information read by a color image scanner or the like of an image input device 20, and a processing target stored in the image holding memory 21. A chromaticity value calculation program 22 for calculating a chromaticity value distribution of a color vector of a pixel of an object; a chromaticity value holding memory 23 for storing chromaticity values calculated by the chromaticity value calculation program 22; A color vector detection program 24 for detecting an object color vector of a processing target object and an illumination light vector of illumination light for illuminating the processing target object while referring to data stored in the degree value holding memory 23. .

FIG. 4 shows an embodiment of a processing flow executed by the chromaticity value calculation program 22, and FIGS. 5 to 8 show an embodiment of a processing flow executed by the color vector detection program 24. Next, the object color vector detection processing according to the present invention will be described in detail according to these processing flows. Here, in the embodiments described below, an achromatic white light source is assumed as the illumination light.

When the color vector of each pixel of the object to be processed is extracted from the color vectors stored in the image holding memory 21 by an extraction program or the like (not shown), the chromaticity value calculation program 22 shown in FIG. First, in step 1, one pixel of the non-edge portion is selected from the pixels of the object to be processed, and in step 2, it is determined whether or not all the pixels have been selected. When it is determined that all the pixels have been selected, the process ends. When it is determined that the pixels have been selected, the process proceeds to step 3, where the color vectors of the selected pixels are stored in the image holding memory 21. Read from

Subsequently, in step 4, the brightness of the color vector read out in step 3 is calculated according to the above-mentioned equation (4), and it is determined whether or not the calculated brightness is a specified level or more. to decide. If it is determined in step 4 that the brightness of the color vector read out in step 3 is equal to or higher than the specified level, the process proceeds to step 5, where the chromaticity value of the color vector is calculated according to the above-described equation (3). This chromaticity value is stored in the chromaticity value holding memory 23 together with the brightness calculated in step 4. On the other hand, this step 4
If it is determined that the brightness of the color vector read in step 3 is equal to or lower than the specified level, the process returns to step 1 without calculating the chromaticity value because the low-luminance data has a large noise component.

As described above, the chromaticity value calculation program 2
Step 2 calculates the chromaticity value / brightness of the color vector of each pixel of the object to be processed and stores it in the chromaticity value holding memory 23.

When the chromaticity value / brightness of the color vector possessed by the pixel of the object to be processed is stored in the chromaticity value holding memory 23, the color vector detection program 24 executes the processing shown in FIG. First, in step 1, an achromatic chromaticity value indicating a light source characteristic of illumination light is added to the chromaticity value distribution stored in the chromaticity value holding memory 23. In this additional processing, since the achromatic color has a chromaticity value of “r = 0.33, g = 0.33” according to the color vector characteristic of “R = G = B”, this numerical value or a numerical value in the vicinity thereof is added. Or scan white paper with a color image scanner,
By adding the chromaticity value calculated from the read color vector, or extracting the achromatic color of the glossy part of the processing object reflecting the illumination light, the color calculated from the extracted color vector This is done by adding a degree value.

The number of achromatic chromaticity values to be added is determined by multiplying the number of pixels of the object to be processed by a specified ratio value or belongs to the achromatic region of the object to be processed. This is performed by using the number determined by multiplying the number of pixels by the specified ratio value. According to the former method, there is an advantage that the additional number can be easily determined. However, according to the former method, when the chromaticity value distribution indicated by the pixel of the processing target object is biased toward the achromatic region, the chromaticity value of the achromatic region becomes excessive, and the chromaticity value distribution is increased. When the straight line approximating is not passed through the chromaticity value of the object color vector or its vicinity, the object color vector may not be obtained accurately. For this reason, a method of determining the number to be added may be used according to the latter method.

In step 1, when an achromatic chromaticity value is added to the chromaticity value distribution stored in the chromaticity value holding memory 23, in step 2, correction is performed by addition according to the least squares method. A straight line that approximates the obtained chromaticity value distribution is specified. Subsequently, in Step 3, the chromaticity value of the illumination light vector is substantially the same as that of “r = 0.33, g = 0.33”, and the same as in the invention of Japanese Patent Application No. 5-52055 previously filed. From the frequency distribution of the chromaticity values on the straight line, the chromaticity value of the object color vector and the chromaticity value of the illumination light vector located as the end points of the straight line are detected in accordance with the processing of (1).

Subsequently, in step 4, the brightness stored in the chromaticity value holding memory 23 in association with the chromaticity value of the object color vector detected in step 3 and the chromaticity values in the vicinity thereof is stored. It reads out the average value and the one showing the largest value among them is detected as the brightness of the object color vector, and the chromaticity value of the illumination light vector detected in step 3 and the chromaticity value in the vicinity thereof are detected. Then, the brightness stored in association with is read out, and the average value of the brightness values and the one having the largest value are detected as the brightness of the illumination light vector.

Subsequently, in step 5, the chromaticity value (r, r) of the object color vector / illumination light vector detected in step 3
g) and the brightness L of the object color vector / illumination light vector detected in step 4, the object color vector and the illumination light vector are derived according to the above-described [Equation 5], and the process is terminated.

As described above, the color vector detection program 24 executes the processing flow of FIG. 5 to approximate the chromaticity value distribution of the color vector of each pixel of the object with a straight line, thereby obtaining the end point thereof. The chromaticity value of the located object color vector / illumination light vector is detected, and the brightness of the object color vector / illumination light vector is detected from the color vector of the pixel of the object from which the chromaticity value is calculated. When the configuration is adopted in which the object color vector / illumination light vector is detected from these detection values, the chromaticity value of the illumination light vector is forcibly added to the chromaticity value distribution as shown in FIG. Therefore, even if there is no clue to obtain illumination light such as gloss, it is guaranteed that a straight line approximating the chromaticity value distribution passes through the chromaticity value of the object color vector. High precision It becomes possible to detect the object color vector / illumination light vector.

Next, the processing flow of FIGS. 6 to 8 executed by the color vector detection program 24 will be described.
The difference between the processing flow of FIG. 6 and the processing flow of FIG. 5 is that the color vector detection program 24 uses the processing flow of FIG.
In contrast to the configuration in which the chromaticity value of the achromatic color is added to the chromaticity value distribution stored in the chromaticity value holding memory 23 at one time, the processing flow of FIG. When data with chromaticity values are added one by one and a straight line that approximates the chromaticity value distribution at that time is specified, and when the specified straight line passes near the achromatic chromaticity value, ,
The point is that a configuration is adopted in which the additional processing is stopped.

When the color vector detection program 24 executes the processing flow of FIG. 7, first, in step 1, the chromaticity value stored in the chromaticity value holding memory 23 is set to 1
Then, in step 2, the gradient of a straight line connecting the chromaticity value selected in step 1 and the achromatic chromaticity value is calculated. Subsequently, in step 3, it is determined whether or not all chromaticity values have been selected. When it is determined that all chromaticity values have not been selected, the process returns to step 1 to store the chromaticity values in the chromaticity value holding memory 23. The inclination of the straight line is calculated for all the pixels of the object to be processed.

After calculating the inclination of the straight line connecting the chromaticity values of the pixels and the achromatic chromaticity values for all the pixels of the object to be processed in accordance with the processing of steps 1 to 3, the process proceeds to step 4. By calculating the average value of the calculated inclination, a straight line approximating the chromaticity value distribution stored in the chromaticity value holding memory 23 is specified. Here, a median value or a mode value can be used instead of the average value. The straight line specified at this time always passes through the achromatic chromaticity value.

Thereafter, in step 5, the chromaticity value of the object color vector / illumination light vector is detected in accordance with the same processing as step 3 in the processing flow of FIG. 5, and in step 6, the chromaticity value of step 4 in the processing flow of FIG. According to the same processing, the brightness of the object color vector / illumination light vector is detected, and step 7 is performed.
Then, an object color vector / illumination light vector is derived according to the same processing as in step 5 of the processing flow of FIG.

As described above, the color vector detection program 24 executes the processing flow of FIG. 7 to approximate the chromaticity value distribution of the color vector of each pixel of the object with a straight line, thereby obtaining the end point thereof. The chromaticity value of the located object color vector / illumination light vector is detected, and the brightness of the object color vector / illumination light vector is detected from the color vector of the pixel of the object from which the chromaticity value is calculated. In the case of adopting a configuration in which an object color vector / illumination light vector is detected from these detection values, as shown in FIG.
Since the straight line approximating the chromaticity value distribution is forced to pass through the chromaticity value of the illumination light vector, the chromaticity value distribution is approximated even when there is no clue to find the illumination light such as gloss. Is guaranteed to pass through the chromaticity value of the object color vector, and the object color vector /
The illumination light vector can be detected.

Further, the color vector detection program 24
When the processing flow of FIG. 8 is executed, first, in step 1, a plurality of rectangular areas are set with the achromatic chromaticity value as the rotation center. That is, a line passing through the achromatic chromaticity value is set as a center line, and a plurality of rectangular areas whose distance from the center line has a specified width are set. Next, in step 2, the chromaticity values included in each of the rectangular areas set in step 1 are counted, and the chromaticity values are stored in the chromaticity value holding memory 23 in each of the rectangular areas set in step 1. A rectangular area that most overlaps the chromaticity value distribution to be obtained is searched.

Subsequently, in step 3, the chromaticity value distribution stored in the chromaticity value holding memory 23 is approximated by specifying the straight line of the center line of the rectangular area searched in step 2. Identify a straight line.

Subsequently, in step 4, the chromaticity value of the object color vector / illumination light vector is detected in accordance with the same processing as step 3 in the processing flow of FIG. According to the same processing, the brightness of the object color vector / illumination light vector is detected, and step 6 is performed.
Then, an object color vector / illumination light vector is derived according to the same processing as in step 5 of the processing flow of FIG.

The area set in step 1 is not limited to a rectangular area. A natural image from which an object color vector and an illumination light vector can be appropriately obtained is used as a sample, and the average of the shapes of the mixed color straight lines is used. It is also preferable that the setting is made by using the above.

As described above, the color vector detection program 24 executes the processing flow of FIG. 8 to approximate the chromaticity value distribution of the color vector of each pixel of the object with a straight line, thereby obtaining the end point thereof. The chromaticity value of the located object color vector / illumination light vector is detected, and the brightness of the object color vector / illumination light vector is detected from the color vector of the pixel of the object from which the chromaticity value is calculated. In the case of adopting a configuration in which an object color vector / illumination light vector is detected from these detection values, as shown in FIG.
Since the straight line approximating the chromaticity value distribution is forced to pass through the chromaticity value of the illumination light vector, the chromaticity value distribution is approximated even when there is no clue to find the illumination light such as gloss. Is guaranteed to pass through the chromaticity value of the object color vector, and the object color vector /
The illumination light vector can be detected.

Although the illustrated embodiment has been described, the present invention is not limited to this. For example, in the embodiment,
Although the present invention has been disclosed in accordance with the RGB color system, the present invention is not limited to this, and other color systems may be used.

[0066]

As described above, according to the present invention,
By approximating the chromaticity value distribution of the color vector of each pixel of the object with a straight line, the chromaticity value of the object color vector / illumination light vector positioned as the end point is detected, and the chromaticity value calculation source and The brightness of the object color vector / illumination light vector is detected from the color vector of the pixel of the changed object,
When adopting a configuration in which the object color vector / illumination light vector is detected from these detection values, even when there is no clue to obtain illumination light such as gloss, a straight line approximating the chromaticity value distribution is obtained. It is guaranteed to pass the chromaticity value of the object color vector, and the object color vector /
This makes it possible to detect the illumination light vector.

[Brief description of the drawings]

FIG. 1 is a principle configuration diagram of the present invention.

FIG. 2 is a principle configuration diagram of the present invention.

FIG. 3 is a system configuration diagram of the color image processing apparatus of the present invention.

FIG. 4 is an embodiment of a processing flow of a chromaticity value calculation program.

FIG. 5 is an embodiment of a processing flow of a color vector detection program.

FIG. 6 is another embodiment of the processing flow of the color vector detection program.

FIG. 7 is another embodiment of the processing flow of the color vector detection program.

FIG. 8 is another embodiment of the processing flow of the color vector detection program.

FIG. 9 is an explanatory diagram of an execution process of a color vector detection program.

FIG. 10 is an explanatory diagram of an execution process of a color vector detection program.

FIG. 11 is an explanatory diagram of an execution process of a color vector detection program.

FIG. 12 is an explanatory diagram of the invention filed earlier.

FIG. 13 is an explanatory diagram of the invention filed earlier.

FIG. 14 is an explanatory diagram of the invention filed earlier.

FIG. 15 is an explanatory diagram of the invention filed earlier.

FIG. 16 is an explanatory diagram of a problem of the invention filed earlier.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Color image processing apparatus 10 Detected color vector storage means 11 Calculating means 12 Correcting means 13 Identifying means 14 First detecting means 15 Second detecting means 16 Deriving means 17 Setting means 18 Searching means

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ identification code FI G06F 15/72 310 (58) Fields investigated (Int.Cl. ⁷ , DB name) G06T 7/00 G06T 1/00 G06T 5 / 00 G06T 11/00 H04N 1/387

Claims (9)

(57) [Claims] 1. A color image processing apparatus for processing a color vector of each pixel of an object illuminated by illumination light, wherein the chromaticity values of all the color vectors of the pixel of the object or the chromaticity values of the color vectors Calculating means (11) for calculating the chromaticity value of the one with a small noise component, and adding the chromaticity value of the illumination light vector or a chromaticity value in the vicinity thereof to the chromaticity value distribution calculated by the calculating means (11). Correction means (12) for correcting the chromaticity value distribution by specifying the approximation line approximating the chromaticity value distribution generated by the correction means (12); and ) And the correction means (1
A first detection means (14) for detecting one or both of the object color vector and the illumination light vector from the chromaticity value distribution generated by 2), and the first detection means (14 ), The second detecting means (15) for detecting the brightness of one or both of the object color vector and the illumination light vector from the color vector of the pixel of the object while referring to the detection result of The chromaticity value detected by the detecting means (14)
A color image processing device comprising: a deriving means (16) for deriving one or both of an object color vector and an illumination light vector from the brightness detected by the detecting means (15). 2. The color image processing apparatus according to claim 1, wherein the correction means (12) uses the illumination light vector as an achromatic color as a chromaticity value of the illumination light vector used for correcting the chromaticity value distribution. In some cases, the color image processing apparatus performs processing to use a color vector obtained from an achromatic color vector read by an image sensor. 3. The color image processing apparatus according to claim 1, wherein the correction means (12) performs processing so as to add the chromaticity values of the illumination light vectors of a number determined from the number of pixels of the object. A color image processing apparatus. 4. The color image processing device according to claim 1, wherein the correction means (12) calculates the chromaticity values of the illumination light vectors of the number determined by the number of pixels belonging to the achromatic region of the object. A color image processing device characterized by processing to be added. 5. The color image processing apparatus according to claim 1, wherein the correction means (12) sequentially adds the chromaticity values of the illumination light vector, and specifies the identification means (13). A color image processing apparatus that performs processing for continuing this additional processing until an approximation line that passes through the vicinity of the chromaticity value of the illumination light vector. 6. A color image processing apparatus for processing a color vector of each pixel of an object illuminated by illumination light, wherein the chromaticity values of all color vectors of the pixel of the object or A calculating means (11) for calculating a chromaticity value of a component having a small noise component; and a calculating means (11) for calculating the chromaticity value of the illumination light vector on condition that the chromaticity value passes through or near the chromaticity value. Specifying means (13) for specifying an approximation line approximating the chromaticity value distribution; an approximation line specified by the specifying means (13);
A first detection unit (14) for detecting one or both of the object color vector and the illumination light vector from the chromaticity value distribution calculated in 1); and the first detection unit (14). ), The second detecting means (15) for detecting the brightness of one or both of the object color vector and the illumination light vector from the color vector of the pixel of the object while referring to the detection result of The chromaticity value detected by the detecting means (14)
A color image processing device comprising: a deriving means (16) for deriving one or both of an object color vector and an illumination light vector from the brightness detected by the detecting means (15). 7. The color image processing apparatus according to claim 6, wherein the specifying means (13) determines the chromaticity value and the chromaticity value of the illumination light vector corresponding to the chromaticity value calculated by the calculating means (11). By adopting a configuration that calculates the slope of a straight line passing through, and by specifying a representative value of the slope, an approximation line that approximates the chromaticity value distribution calculated by the calculation unit (11) is specified. Processing, characterized in that it is a color image processing apparatus. 8. A color image processing apparatus for processing a color vector of each pixel of an object illuminated by illumination light, wherein the chromaticity values of all the color vectors of the pixel of the object, or the chromaticity values of the color vectors, Calculating means (11) for calculating a chromaticity value of a component having a small noise component; and setting means (17) for setting a plurality of regions of a specific shape with the chromaticity value of the illumination light vector or a chromaticity value in the vicinity thereof as a rotation center.
And each area set by the setting means (17), and the calculation means (1
A search unit (18) that searches for a region having the highest degree of overlap in the area by evaluating the degree of overlap with the chromaticity value distribution calculated in 1), and a search performed by the search unit (18) From the area, the calculation means (1
A specifying means (13) for specifying an approximation line approximating the chromaticity value distribution calculated by (1); an approximation line specified by the specifying means (13);
A first detection unit (14) for detecting one or both of the object color vector and the illumination light vector from the chromaticity value distribution calculated in 1); and the first detection unit (14). ), The second detecting means (15) for detecting the brightness of one or both of the object color vector and the illumination light vector from the color vector of the pixel of the object while referring to the detection result of The chromaticity value detected by the detecting means (14)
A color image processing device comprising: a deriving means (16) for deriving one or both of an object color vector and an illumination light vector from the brightness detected by the detecting means (15). 9. The color image processing apparatus according to claim 8, wherein the search means (18) performs processing to evaluate the degree of overlap using the number of chromaticity values included in the area. Image processing device.