JPH0744681A - Color picture processor - Google Patents

Abstract

PURPOSE:To change color even when the color of object image 15 the same as the illumination light and the two-dimensional reflection light and an object reflection model cannot be specified by changing the color of the object picture according to the object reflection model. CONSTITUTION:The device is provided with a judgement means 16 judging whether or not the object color vector specified for the calculation of the parameter of the object reflection model is almost the same as the illumination light vector or the two-dimensional reflection light vector and calculation means 20 calculating the color data after changing the color of each picture element of the object picture based on the object color vector being the condition of changing colors and the color data before changing the color of each picture element of the object picture, and the characteristic color data specified relating to the color data when the judgement means 16 judges the same color. The judgement means 16 judges the same color, the color display processing of the object picture is performed according to the color data calculated by the calculation means 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image processing apparatus for processing an object image in a color image so as to change the color of the object image. In particular, the object image has the same color as illumination light or secondary reflected light. The present invention also relates to a color image processing device that enables color change processing.

In an electronic catalog creating system for products using a computer and an electronic designing system such as a poster using a computer, a basic color image is read by a reading device and displayed on a color monitor. By changing the color of the object image in the image, the process of completing the catalog and the design will be executed. Also, when creating computer graphics, similarly, a color changing process of changing the color of the object image in the color image is executed.

In such a color changing process of a color image on a computer, it is necessary to change the color while preserving the atmosphere of the entire image to be changed.

[0004]

2. Description of the Related Art Conventionally, as a method of changing the color of an object in a color image while preserving the naturalness of the image, a method of changing only the hue value of the color data of the object or a simple object reflection model has been used. There was something to do. In addition, in changing the glossiness or the material appearance, there is a method in which another object having a different glossiness or material is separately input in advance and the objects are attached to each other.

However, if the color is changed only by the hue value, the color can be changed while preserving the naturalness such as the shadow and gloss of the surface of the object to some extent. However, there is a problem in that the appearance of shadows, gloss, etc. becomes unnatural, such as the shadow becomes whitish or the gloss disappears.

Further, in the color change using a simple object reflection model, even if the color is subtle, it can be changed while preserving the naturalness to some extent, but only the color can be changed, and the gloss and the appearance of the color can be changed. Change (for example, the effect of giving directionality to the appearance of colors and making them appear to shine)
I couldn't.

In addition, in order to change the glossy feeling and material feeling,
In the method of separately inputting another object in advance, there is a problem that inputting is troublesome, and only the characteristics of the input object can be changed, and the change cannot be freely performed.

Against this background, the applicant of the present invention has previously filed Japanese Patent Application No. 3-195326 (Title of Invention: Color Image Control Method) by using a strict object reflection model. The invention has been disclosed in which the color of an object in an image can be changed while preserving the naturalness of the image, and also the appearance of gloss and color can be changed.

That is, in the present invention, if the explanation is made assuming the RGB color system,

[0010]

[Equation 1]

As shown by, the object color vector (Rd, Gd,
Bd) and the coefficient value K1 are defined by the vector, the illumination light vector (Rs, Gs, Bs) is multiplied by the coefficient value K2, and the secondary reflected light vector (Ra, Ga, Ba) and the object defined that color data (Ro, Go, Bo) of each point (each pixel) of the object is represented according to the addition vector of the vector defined by the multiplication value of the coefficient value K3. The reflection model was derived.

When changing the color of an object in a color image, first, the object color vector (Rd, Gd, Bd) of the object is specified according to the object reflection model, and the object is identified. Illuminating light vector (Rs, Gs, Bs) and secondary reflected light vector (Ra, Ga, B)
a) is assumed to be appropriate. Then, with this state,
Since the color data (Ro, Go, Bo) of each pixel of the object before the color change is known, and the ternary simultaneous equations defined by [Equation 1] can be solved, the pixel data of each pixel of the object can be solved. The coefficient values K1, K2 and K3 that it has are calculated.

For example, when changing the color of a blue car displayed on the display screen, by interacting with the operator, the most appropriate blue color is selected from the colors of the car, and the object color vector is selected. By specifying (Rd, Gd, Bd) and interacting with the operator, a white illumination light vector (Rs, Gs, Bs) and an appropriate secondary reflected light vector (Ra, Ga, Ba) are assumed. To do. And
By solving the ternary simultaneous equations defined by the equation 1,
The coefficient values K1, K2, K3 of each pixel of the object are calculated.

Next, the object color vector (R
When d ', Gd', Bd ') are determined, the calculated coefficient value K
Using 1, K2 and K3,

[0015]

[Equation 2]

According to the above, the color data (R
By calculating o ', Go', Bo '), the color data of each pixel of the object after the color change is determined. At this time, the illumination light vector (Rs, Gs, Bs) and the secondary reflected light vector (Ra, Ga, Ba) may be changed. From this, the formula [2] is

[0017]

[Equation 3]

## EQU3 ## At least one of the object vector, the illumination light vector, and the secondary reflected light vector in the equation (3) is represented by the equation (1).
By changing from the expression, the color change processing of the object is executed.

For example, in the case of changing the above-mentioned automobile to red according to the formula (2), the red object color vector (Rd ', Gd', Bd ') is determined by interacting with the operator. Using the calculated coefficient values K1, K2, K3,
Color data (Ro ', G of each pixel of the object is calculated according to the formula [2].
o ', Bo') will be decided.

In this way, according to the invention previously applied, it is possible to change the color of an object in a color image while preserving the naturalness of the image.

[0021]

Certainly, according to the invention of this earlier application, it becomes possible to change the color of an object in a color image while preserving the naturalness of the image.

However, the object color vector (Rd, Gd, Bd) and the illumination light vector (Rs, Gs, Bs) are required in order to be able to calculate the coefficient value Ki according to the above-mentioned equation (1).
And the secondary reflected light vector (Ra, Ga, Ba) are of different colors. Otherwise, the ternary simultaneous equations of [Equation 3] cannot be solved.

However, normally, the illumination light is white, and from this, when the object color is achromatic, the coefficient value Ki cannot be calculated according to the formula [1]. There was a problem that the change process could not be executed.

The present invention has been made in view of such circumstances, and there is a case where a structure for changing the color of an object image in a color image is adopted according to the invention of Japanese Patent Application No. 3-195326 previously filed. An object of the present invention is to provide a new color image processing apparatus that enables color change processing even if the color of the object image is the same color as the illumination light or the secondary reflected light.

[0025]

FIG. 1 shows the principle configuration of the present invention. In the figure, 1 is a color image processing apparatus including the present invention, 2 is a man-machine interface apparatus included in the color image processing apparatus 1, and 3 is an input apparatus included in the man-machine interface apparatus 2.

The color image processing apparatus 1 includes an input / output control unit 10, a color image data management unit 11, a color image data display control unit 12, an object extraction unit 13, a reflection model setting unit 14, and a coefficient value calculation. Means 15, same color judgment means 16, coefficient value management means 17, color change condition setting means 1
8 and a first changed color data calculation means 19 and a second changed color data calculation means 20.

The input / output control means 10 is a man-machine
The interface processing with the interface device 2 is executed. The color image data management means 11 manages the color data of each pixel of the color image displayed on the display screen of the man-machine interface device 2. The color image data display control means 12 displays a color image on the display screen of the man-machine interface device 2 according to the management data of the color image data management means 11.

The object extracting means 13 extracts a color change object from the color image displayed on the display screen of the man-machine interface device 2. The reflection model setting means 14 interacts with the input device 3 to obtain [Equation 1].
The vector values of the object color vector, the illumination light vector, and the secondary reflected light vector of the object reflection model represented by the equation are set.

The coefficient value calculating means 15 solves the ternary simultaneous equations defined by the equation (1) according to the vector value set by the reflection model setting means 14, so that each pixel of the color change object has The coefficient value Ki is calculated. The same color determination means 16 is expanded to, for example, the coefficient value calculation means 15,
It is determined whether the object color vector set by the reflection model setting means 14 is substantially the same color as the illumination light vector or the secondary reflected light vector that is also set. The coefficient value management unit 17 manages the coefficient value Ki of each pixel of the color change target object calculated by the coefficient value calculation unit 15.

By interacting with the input device 3, the color change condition setting means 18 sets the vector values of the object color vector, the illumination light vector and the secondary reflected light vector of the object reflection model which are the color change conditions. The first changed color data calculation means 19 uses the coefficient value Ki of each pixel managed by the coefficient value management means 17 and the vector value set by the color change condition setting means 18 to calculate the color according to the formula [3]. The color data after the color change of each pixel of the object to be changed is calculated and stored in the color image data management unit 11.

The second changed color data calculation means 20 associates the vector value set by the color change condition setting means 18, the color data of each pixel of the color change object before the color change, and the color data. The color data after the color change of each pixel of the color change target object is calculated from the characteristic color data specified by the above and stored in the color image data management unit 11.

[0032]

In the present invention, the object extracting means 13 extracts the color change target object by interacting with the operator, and the reflection model setting means 14 interacts with the input device 3.
For example, the object color vector (Rd, Gd, Bd) in [Equation 1] is set by designating one point in the color change target object, and the illumination light vector illuminating the color change target object. (Rs, Gs, Bs) and the secondary reflected light vector (Ra, Ga, Ba) are set.

In this way, the reflection model setting means 14
When the vector value is set by, the coefficient value calculation means 15
Reads the color data of each pixel of the color change target object extracted by the object extracting unit 13 from the color image data managing unit 11, and according to the read color data and the vector value set by the reflection model setting unit 14. By solving the ternary simultaneous equations defined by the equation 1, the coefficient value Ki of each pixel of the color change object is calculated and stored in the coefficient value management means 17.

At this time, the same color judging means 16 judges whether or not the object color vector set by the reflection model setting means 14 is substantially the same color as the illumination light vector or the secondary reflected light vector which is also set. However, in response to this determination result, when the same color determination unit 16 determines that the same color determination unit 16 has the same color, the coefficient value calculation unit 15 cannot solve the simultaneous equations of three elements, and thus the coefficient value Ki is calculated. Process not to execute.

On the other hand, the color change condition setting means 18 sets the vector values of the object color vector, the illumination light vector, and the secondary reflected light vector of the object reflection model, which are the color change conditions, by interacting with the input device 3. To do. That is, the vector values of the object color vector, the illumination light vector, and the secondary reflected light vector in the equation (3) are set.

In this way, when the coefficient value management means 17 stores the coefficient values Ki of all the pixels of the color change object and the vector value is set by the color change condition setting means 18, the first changed color data is obtained. The calculation means 19 is a coefficient value management means 17
The coefficient value Ki of each pixel is read from, and the read coefficient value Ki and the vector value set by the color changing condition setting means 18 are substituted into the ternary simultaneous equations defined by the formula [3]. As a result, new color data of each pixel of the color change target object is calculated and stored in the color image data management means 11.

At this time, the coefficient value K is stored in the coefficient value management means 17.
When i is not stored, that is, when the same color determination unit 16 determines that the same color is determined, the first changed color data calculation unit 19 cannot calculate new color data of the color change target object. Since it becomes possible, the second changed color data calculation means 20 has the object color vector set by the color change condition setting means 18 and each pixel of the color change target object stored in the color image data management means 11. From the color data before the color change and the characteristic color data specified in association with the color data, new color data of each pixel of the color change target object is calculated and stored in the color image data management means 11. .

In response to this storage processing, the color image data display control means 12 displays the color of each pixel of the color change target object on the display screen of the man-machine interface device 2 according to the changed color data. To go.

As described above, according to the present invention, in accordance with the invention of Japanese Patent Application No. 3-195326 previously filed, the color of an object in a color image can be changed while preserving the naturalness of the image. Even when the color of the object image that is the target of the color change processing is the same color as the illumination light or the secondary reflected light, the color change processing can be performed.

[0040]

EXAMPLES The present invention will be described in detail below with reference to examples. FIG. 2 illustrates the system configuration of a color image processing system that implements the present invention. In the figure, 30 is a color image processing apparatus for realizing the present invention, and 40 is a color image processing apparatus 3.
An image input device connected to 0 and a color monitor 50 connected to the color image processing device 30.

The color image processing apparatus 30 includes an image holding memory 3 for holding color image data information read by an image scanner or the like of the image input apparatus 40.
1 and whether or not the above-described coefficient value Ki to be assigned to each pixel stored in the image holding memory 31 can be calculated. A new color image data information is obtained and expanded in the image holding memory 31 by using the parameter calculation program 32 to be developed into and the coefficient value Ki calculated by the parameter calculation program 32.
When it is determined by the parameter calculation program 32 that the coefficient value Ki cannot be calculated, the new color image data information is obtained according to a prescribed algorithm without using the coefficient value Ki, and the image data to be expanded in the image holding memory 31. It is composed of a calculation program 33 and a display memory 34 which reads out color image data information to be displayed on the color monitor 50 from the image holding memory 31 and expands it.

FIG. 3 shows an example of the processing flow executed by the parameter calculation program 32, and FIG. 4 shows an example of the processing flow executed by the image data calculation program 33. Next, the color image color changing processing of the present invention will be described in detail according to these processing flows.

When changing the color of the color image displayed on the color monitor 50, the parameter calculation program 3
In step 2, as shown in the processing flow of FIG. 3, first, in step 1, a color change target object is extracted from the color image. This extraction processing is, for example, extraction of an object cut out by a mouse or the like included in the image input device 40 as a color change target object, or an object having a color of the same system as the color pointed by the mouse or the like included in the image input device 40. Is extracted as the color change target object, or the edge of the object is detected by differential processing or the like and the inside thereof is extracted as the color change target object.

Next, in step 2, by interacting with the image input device 40, the operator can designate, for example, one point representing the most object color among the color change target objects displayed on the color monitor 50. , By setting the object color vector (Rd, Gd, Bd) of the currently displayed color change target object and interacting with the image input device 40, the illumination light vector (Rs ,
Gs, Bs) and the secondary reflected light vector (Ra, Ga, Ba) are set. According to this setting process, since the color data (Ro, Go, Bo) of each pixel of the currently displayed color change target object is known, by solving the ternary simultaneous equations defined by the formula [1], , The coefficient values Ki of those pixels can be calculated.

Since the illumination light is usually white, the illumination light vector (Rs, Gs, Bs) is assumed to be white here. That is, it is assumed that “Rs = Gs = Bs”. Then, in step 3, it is determined whether the object color vector (Rd, Gd, Bd) of the color change object set in step 2 is an achromatic color or a chromatic color. This determination process is, for example,

[0046]

[Equation 4]

According to the RGB color system, the chromaticity coordinate values (r, g) of the object color vector (Rd, Gd, Bd) are calculated, and the chromaticity coordinate values (r, g) and the achromatic color are calculated. Chromaticity coordinates (0.
3333, 0.3333) is executed by determining whether or not the distance from the 3333, 0.3333) is smaller than a specified reference value.

In addition to this, the object color vector (Rd, Gd, Bd
) Is converted to the coordinate value of the uniform color space, the distance between this coordinate value and the axis of the achromatic color in the uniform color space is calculated, and it is judged whether this distance is smaller than the specified reference value. It is also possible to adopt a method of determining whether or not it is an achromatic color by going through. It is said that the uniform color space corresponds well to the difference in color that humans perceive and the color difference that is a numerical value.Therefore, if this method is adopted, the reference value used to determine whether or not it is an achromatic color. Is constant, there is an advantage that the judgment can be accurately made regardless of whether the object color is bright or dark.

Subsequently, in step 4, it is judged whether or not the color is achromatic in step 3, and when it is judged that the color is achromatic, the coefficient value Ki can be calculated according to the equation [1]. Since it is impossible, the process proceeds to step 5, the image data calculation program 33 is notified of that fact, and the process ends. On the other hand, when it is determined that the color is not achromatic, that is, when it is determined that the color is chromatic, step 6
Proceed to, and color data (Ro, G
o, Bo) is read from the image holding memory 31, and the ternary simultaneous equations defined by the equation (1) are used according to the read color data (Ro, Go, Bo) and the vector value set in step 2. By solving, the coefficient value Ki of each pixel of the color change target object is calculated, and the process ends.

In this way, the parameter calculation program 32 calculates the coefficient value Ki of each pixel of the color change target object and stores it in the image holding memory 31, or the coefficient value Ki is stored.
When it is determined that the color change target object is not calculated, the image data calculation program 33 executes the process flow of FIG. 4 to change the color of the color change target object displayed on the color monitor 50. Run.

That is, the image data calculation program 33
As shown in the processing flow of FIG. 4, first, in step 1, by interacting with the image input device 40, an object color vector (Rd ′, Gd ′, Bd ′) that is a color change condition, The illumination light vector (Rs ', Gs', Bs ') and the secondary reflected light vector (Ra', Ga ', Ba') are set. This setting process is realized by allowing the operator to directly input the RGB values, or by adopting a configuration in which a color sample is displayed on the color monitor 50 and allowing the operator to select it.

For example, when changing the color of the color change target object by changing the color of the color change target object itself, the parameter calculation program 32 calculates the object color vector (Rd ', Gd', Bd ') to obtain the coefficient value Ki. When the color of the color change target object is changed by changing the illumination light, the illumination light vector (Rs', Gs', Bs') is set to the parameter calculation program 32.
Is set to a value different from that set when the coefficient value Ki is calculated, and when the color of the color change target object is changed by changing the secondary reflected light, the secondary reflected light vector (R
a ', Ga', Ba ') is set to a value different from that set by the parameter calculation program 32 when the coefficient value Ki is calculated, and when the color of the color change target object is changed by a combination of these, The vector value of is set to a value different from that set when the parameter calculation program 32 calculates the coefficient value Ki.

Next, in step 2, it is judged whether or not there is a notification indicating that the color is achromatic from the parameter calculation program 32, and if it is judged that there is no notification of the achromatic color, the process proceeds to step 3 and the image is displayed. The coefficient value Ki possessed by each pixel is read from the holding memory 31, and the read coefficient value Ki and the vector value set in step 1 are substituted into the ternary simultaneous equations defined by equation (3). As a result, new color data (Ro ', Go', Bo ') of each pixel is calculated and stored in the image holding memory 31. Then, in response to this storage processing, the color monitor 50 displays the color-change target object whose color has been changed.

On the other hand, if it is determined in step 2 that an achromatic color has been notified, the process advances to step 4 to execute a search process for the maximum luminance value among the color data of each pixel of the color change object. . This search processing is executed by, for example, adding the RGB values of the color data for each pixel and searching for the color data having the maximum value of the added values.

Subsequently, in step 5, the maximum luminance color data (Rmax, Gmax, Bmax) retrieved in step 4 and the object color vector (Rd ', Gd', Bd ') set in step 1
And the color data (Ro, Go, Bo) before the color change of each pixel of the color change target object read from the image holding memory 31

[0056]

[Equation 5]

According to the above, the color data (Ro ', Go', Bo ') after the color change of each pixel of the color change object is calculated and stored in the image holding memory 31. Then, in response to this storage processing, the color monitor 50 displays the color-change target object whose color has been changed. Here, in the formula (4), in order to maintain the balance between the brightness of the color change area and the brightness of the background image, the maximum luminance color data (Rmax, Gmax,
Bmax) was used, but it is also possible to use preset fixed color data such as 80% of the possible values.

Thus, by using the present invention,
The object color vector (Rd, Gd, Bd) and the illumination light vector (Rs, Gs, Bs) that constitute the object reflection model of the formula [1]
Even if the second-order reflected light vector (Ra, Ga, Ba) is not a different color, the object color changing process can be executed.

Although the illustrated embodiment has been described, the present invention is not limited to this. For example, in the example,
Although the present invention has been disclosed according to the object reflection model represented by the RGB color system, the present invention is not limited to this and may be an object reflection model represented by another color system.

[0060]

As described above, according to the present invention,
According to the invention of Japanese Patent Application No. 3-195326 filed by the present applicant, there is a case where the color of an object in a color image can be changed while preserving the naturalness of the image.
Even if it becomes impossible to calculate the parameters required for this color changing process because the color of the object image that is the target of the color changing process is the same color as the illumination light or the secondary reflected light. The color changing process can be performed.

[Brief description of drawings]

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

FIG. 2 is a system configuration diagram of a color image processing system implementing the present invention.

FIG. 3 is an example of a processing flow of a parameter calculation program.

FIG. 4 is an example of a processing flow of an image data calculation program.

[Explanation of symbols]

 1 Color Image Processing Device 2 Man-Machine Interface Device 3 Input Device 10 Input / Output Control Means 11 Color Image Data Management Means 12 Color Image Data Display Control Means 13 Object Extracting Means 14 Reflection Model Setting Means 15 Coefficient Value Calculating Means 16 Same Color Judgment Means 17 Coefficient value management means 18 Color change condition setting means 19 First changed color data calculation means 20 Second changed color data calculation means

Claims (5)

[Claims] 1. The object color vector multiplied by a coefficient value K1 and the illumination light vector multiplied by a coefficient value K2 are used for the color data of each pixel of the color change target object displayed on the display device.
The configuration is expressed by the addition vector with the secondary reflected light vector multiplied by the coefficient value K3, and when the object color vector, the illumination light vector and the secondary reflected light vector are designated, these vectors and the color are changed. According to the color data of the pixel of the target object, the coefficient value Ki (i = 1 to 3) of each pixel of the color change target object is calculated, and the object color vector and the illumination light vector that are the color change conditions are adopted. And when the secondary reflected light vector is given, the color data after color change of each pixel of the color change target object is calculated from these vectors and the calculated coefficient value Ki and displayed on the display device. In the color image processing device for performing the processing, the object color vector designated for calculating the coefficient value Ki is the illumination light vector or the secondary reflected light designated for calculating the coefficient value Ki. Judgment means (16) for judging whether or not the color is substantially the same as the color of the object, and when the judgment means (16) judges the same color, the object color vector that is the color change condition and the color change target object Calculation means (20) for calculating the color data after the color change of each pixel of the color change target object from the color data before the color change of each pixel and the characteristic color data specified in association with the color data When the determination means (16) determines the same color, the color display processing of the color change target object is executed according to the color data calculated by the calculation means (20). Color image processing device. 2. The color image processing apparatus according to claim 1, wherein the calculating means (20) is configured to use, as the characteristic color data, one showing the maximum luminance value of the color data of the pixel before color change. A color image processing apparatus characterized by being performed. 3. The color image processing apparatus according to claim 2, wherein the calculation means (20) includes an object color vector which is a color change condition,
Calculate the value obtained by dividing the product of each pixel of the color change target object and the color data before color change by the characteristic color data as the color data after each color change of each pixel of the color change target object. A color image processing device characterized by processing. 4. The color image processing apparatus according to claim 1, 2 or 3, wherein the judging means (16) designates an object color vector designated for calculation of the coefficient value Ki and a designation for calculation of the coefficient value Ki. By calculating a color component difference value between the illumination light vector and the secondary reflected light vector, and comparing the color component difference value with a prescribed reference value, the object color vector becomes the illumination light vector or the illumination light vector. A color image processing device characterized by performing processing so as to determine whether or not the color is substantially the same as that of the secondary reflected light vector. 5. The color image processing apparatus according to claim 4, wherein the determination means (16) performs processing so as to obtain a color component difference value in a uniform color space.