JPH05128224A - Color extracting device for color picture and method therefor - Google Patents

Abstract

(57) [Summary] [Object] The present invention specifies an arbitrary color in a color image,
An object of the present invention is to enable a color extraction device and method of a color image by a computer 10 for extraction, classification and identification to enable accurate color extraction by a simple operation. [Structure] A representative point determining unit 15 inputs a point in a region to be extracted on a display screen or a region to be deleted from an extracted image by instructing the position input device 12, and determines a plurality of representative points based on the input. .. Range instruction input section 16
Enter a parameter that specifies the range of colors to be extracted or deleted. The color extraction unit 17 defines the solid in the color space by the color of the representative point of the extraction area and the parameter that specifies the range of the extracted color, and selects the image data of the color to be extracted from the image holding memory 14. The data deleting unit 18 removes the image data of the color to be deleted from the image of the extraction result by the representative point of the deletion area and the parameter designating the range of the color to be deleted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image color extracting apparatus and method by a computer for designating, extracting, classifying and identifying an arbitrary color in a color image.

Color extraction is required when adjusting colors used in a design system using a computer and a color monitor, creation of computer graphics, and the like. In computer-based designs such as products (for example, packages and cars) and posters, an image is created on a monitor, or a basic image is input by an image reading device, and each part of the image is input. Assign colors. In the process of finishing these images, it is necessary to adjust and correct the assigned colors. Further, in the creation of computer graphics, it is necessary to adjust the colors of created images.

In the use of color adjustment / correction on a computer, it is necessary to first specify a color or an object to be adjusted and extract a part to be adjusted / corrected. In order to specify and extract colors for this purpose, there is a need for technology that realizes an even easier-to-use human interface and technology that improves extraction accuracy.

[0004]

2. Description of the Related Art There have been the following conventional color extraction methods. An operator traces the outer circumference of the area to be extracted in a color image displayed on a monitor with a light pen or the like.

In addition, even if the color image data looks like the same color, it is necessary to determine the range to some extent due to color variations and noise. For that purpose, it is necessary to determine the range of color data to be extracted. The following methods are used to determine this range.

A range of colors to be extracted is determined for each image data represented by a combination of RGB data. RGB data is converted into data in a color space represented by hue, saturation, and lightness such as the HSV color system, and the threshold value of each parameter is determined to separate and extract colors.

Conventionally, color extraction has been performed by the above method.

[0008]

The above-mentioned conventional techniques have the following problems, respectively. The work of tracing the extraction area with a light pen is complicated.
In addition, when working with a mouse or the like, it takes time and effort to switch to a light pen, which imposes a heavy burden on the operator.

Since the color represented by RGB data does not match the intuition of human beings, it is difficult to know how much range each data should be specified to extract a desired color.

The HSV color system is relatively good for human senses, but since there are three parameters that determine the range,
It is difficult to specify the extraction range. Even if the images look the same, the actual image data may vary due to noise, etc., so it is necessary to extract a range of colors including those. It is difficult to estimate this range.

When the extraction result is unsatisfactory (when unnecessary colors are also extracted, or when the color to be extracted remains), the first result is fed back and the range is returned. It is sensuously difficult to reassign the parameters that determine

In order to solve the above problems, the present inventors consider the following color extraction method and color extraction device. The operator can specify the color (representative color) to be extracted by using the device currently used by the operator such as a mouse or light pen. Specifically, the color can be specified by clicking one point or a plurality of points of the color to be extracted with the mouse or designating with a light pen.

As a method of specifying the range of colors to be extracted,
Allows specification with one parameter. A range of colors is defined in a three-dimensional solid centered on the specified color.
A solid that can represent the size of a three-dimensional solid with a single parameter is used.

According to the above method, it is possible to reliably extract the color to be extracted, and increase the parameter if the extracted color range is narrow, and decrease the parameter if the extracted color range is wide. It is possible to perform the color extraction process with various operations.

However, when it is desired to extract a specific object, the range of colors that normally appear on the surface of the object is wide, and if the parameter is increased accordingly, even similar colors in parts other than the extraction target in the image are taken too far. It may end up. vice versa,
If the parameter is reduced in order to avoid extraction of a similar color in a portion other than the extraction target, the color of the extraction target object may be left behind.

In color extraction of a color image, even if such parameters are adjusted, too much or too much of the image is left behind, and it is difficult to extract only the desired region. For these, technical means that can further improve the extraction accuracy are needed.

It is an object of the present invention to solve the above problems, to provide a means which is easy to operate and which can improve the accuracy of extraction.

[0018]

FIG. 1 illustrates the principle of the present invention. In FIG. 1, 10 is a computer for processing image data including a CPU and a memory, 11 is an image input device such as an image scanner, 12 is a position input device such as a mouse or a light pen, 13 is a color display, 14
Is an image storage memory for storing input image data, 15 is a representative point determination unit for inputting points in the area to be extracted or deleted on the screen, and a plurality of representative points is determined, and 16 is a parameter for designating a color range. An area instruction input unit for inputting, a color extracting unit 17 for selecting image data of a specified color from the image holding memory 14, a data deleting unit for removing image data of the color to be deleted from the image of the extraction result, and a color deleting unit. A display memory for storing display data on the display 13,
Reference numeral 20 represents a cursor such as a mouse cursor indicating a specific position on the screen.

Image input device 11 such as an image scanner
Input image data such as RGB signals input from
It is stored in the image holding memory 14. The image data is first sent to the display memory 19 of the display as it is, and the color image is displayed on the color display 13.

When there is a color extraction instruction, the representative point determination section 15 inputs the position information of the point in the image designated by the operator by the position input device 12, and based on this, for example, a plurality of different brightness values are input. Select a representative point. The range instruction input unit 16 inputs a parameter that specifies a range of colors to be extracted. As a result, the color extraction unit 17 causes the representative point determination unit 15 to
Image data to be extracted from the image holding memory 14 for color adjustment or the like is selected based on the color of the representative point determined by the above and the parameter designating the color range.

If too many points are extracted, the representative point determining section 15 similarly inputs the points of the area to be deleted and determines the representative points. Further, the range instruction input unit 16 inputs the parameter of the color range to be deleted, and the data deleting unit 18 extracts the image data of the overextracted portion by using the color of the representative point and the parameter of the color range to be deleted. Remove from.

In the color extracting method of the color image according to claim 2, the color image to be extracted is displayed on the color display 1.
3 and the representative point determination unit 15 instructs and inputs one or more points in the area to be extracted in the displayed image, and further selects a plurality of representative points from the area including the instructed point. The process of selecting points and the colors included in a solid having a predetermined size or a specified size in a color space centered on the colors of a plurality of representative points by the range designation input unit 16 and the color extraction unit 17. The process of extracting the image data of the region having

According to a third aspect of the present invention, there is provided a color extracting method for a color image, wherein in each of the processing steps of the second aspect, a step of displaying a portion of the extracted image data on the color display 13 in such a manner that the range can be understood, A process of instructing and inputting one or a plurality of points of the region to be deleted from the extraction target by the point determining unit 15 and selecting a plurality of representative points from the region including the point designated as the deletion target, and the data deleting unit 1.
By 8, the image data of the area having the color included in the solid having the predetermined size or the specified size in the color space centered on the colors of the plurality of representative points is removed from the previously extracted image data. It consists of a process and.

[0024]

According to the present invention, a plurality of representative points are designated, a plurality of solids are used in the color space based on these representative points, a region is three-dimensionally defined, and a color is extracted. In particular, the characteristic of the distribution of the image data is used to define a solid as a representative point, for example, a bright point, a dark point, and an intermediate brightness point with the same hue to improve the extraction accuracy. Furthermore, show the extraction result to the operator, and extract too much (unnecessary part)
Is specified again, and the specified point is used as the representative point to define the area in the color space, thereby deleting the specified area from the extracted image.

In the present invention, by using the means for extracting a color by using a plurality of solids in this way, it is possible to improve the extraction accuracy in addition to the advantage that the representative color can be easily specified and the extraction range can be set easily. Has the advantage that In addition, if the extraction result is shown to the operator and there is an unextracted part, the representative color of the unnecessary part can be specified and the unnecessary part can be deleted from the image of the extraction result in the same way as the extraction. Can improve the accuracy of extraction.

[0026]

Embodiment FIG. 2 shows a processing flow of an embodiment of the present invention. The processing will be described below in accordance with the processing shown in FIG.

A color image that is a color extraction target is displayed on the color display 13. In the color image displayed on the display, let the operator point one or more points in the extraction area with a mouse or a light pen.

Based on the designated points, some points (for example, a bright place, a dark place, an intermediate brightness, etc.) are selected as representative points. The selection method will be described later. Furthermore, the operator specifies and inputs the size of the three-dimensional solid that is the range defining the area in the color space. For example, if the solid is a sphere, the radius of the sphere is input as a parameter.

A region centered on the color of the representative point in the color space is defined by the designated size, and the image holding memory 14 is referenced to extract the image data contained therein. The extraction result is displayed on the color display 13 so that it can be distinguished by changing the color.

The operator confirms the result, and if the operator sees the extraction result and is satisfied, the extraction process is terminated. If it is not satisfied, the process is returned to, the extraction range is changed, and the extraction process and the extraction result are displayed again. The above process is repeated until the input instruction is satisfied with the result.

FIG. 3 is an explanatory diagram of extraction processing in the embodiment of the present invention. In particular, FIG. 3A is a diagram for explaining the designation of the extraction target region, and FIG. 3B is a diagram for explaining the color extraction in the region occupied by a plurality of solids in the color space.

In the above-described processing shown in FIG. 2, the target image A is displayed on the color display 13 as shown in FIG. According to the processing shown in FIG. 2, the operator operates a mouse or the like to designate one point or a plurality of points of the extraction target area with the cursor 20. When the mouse button is pressed, the position of the cursor 20 is read and the point is recognized as the designated point.

The range of colors to be extracted is determined by the solid in the color space as shown in FIG. In this example, the color space is a space determined by the coordinate system of hue, saturation, and lightness. Three spheres 30 centered on a representative point 31 defined from designated points in this color space
The area is defined by and the image data is extracted.

The range for extracting data is specified by the radius of the sphere. Since the colors to be extracted are often the same hue in normal image data processing, in this example, the three representative points 31 are narrow in the hue direction and widely distributed on the plane of lightness and saturation. The relationship has been established.

FIG. 4 is an explanatory diagram for determining representative points according to the embodiment of the present invention.
The following shows how to find points with high and low brightness and points with intermediate brightness.

The selection / determination of the representative point from the designated points is performed as follows, for example. The image data of the area around the specified one or more points are checked for the same hue, and the brightness (for example, brightness value) of those data is plotted on the horizontal axis,
Distribution is calculated with the frequency of occurrence of data as the vertical axis. In this way, when a plurality of points in the bright area, dark area, and intermediate brightness area of the extraction area are specified at random, in many general images, such as images of products such as packages and cars, it is shown in Fig. 4. It is empirically known that such a distribution will be obtained.

Therefore, a point having a lightness value with a maximum appearance frequency among low brightness, high brightness, and intermediate brightness is set as a representative point. When the appearance frequency with respect to the lightness does not form three peaks as shown in Fig. 4, the lightness with the highest appearance frequency (usually the intermediate lightness point)
A lightness value point appropriately separated in the high and low lightness directions with respect to each other may be selected as a representative point.

FIG. 5 is an explanatory diagram of extraction by a plurality of solids according to the embodiment of the present invention, showing that the sizes of the plurality of solids are changed to define a region in the color space.
This depends on the characteristics of the color space used for extraction.

For example, in a uniform color space such as CIELAB or CIEUV, since the difference between the colors seen by a human and the distance between the colors in the color space correspond to each other, the colors are relatively evenly distributed and the colors can be easily extracted. As is well known in color engineering, L * represents the brightness of this space, and the color difference is represented by the position of the a * b * plane. The closer to the origin, the lower the saturation, and the further away from the origin, the higher the saturation. There are two color distributions, white (high brightness, low saturation) and black (low brightness, low saturation).
It has a shape with a bulge in the middle lightness, with one as the apex. Therefore, the size of the solid for extracting the high brightness and low brightness portions is small, and the larger the solid for extracting the color of the intermediate brightness is, the better the extraction accuracy is.

That is, as shown in FIG. 5, the sphere 30B in the intermediate lightness portion is made large and the spheres 30A, 30C in the high and low lightness portions are made small. This ratio may be determined internally in advance or may be determined by inputting parameters.

FIG. 6 shows the flow of color extraction processing when an unnecessary area is deleted from the extraction result data. The difference from the process flow of the embodiment shown in FIG. 2 is that a process of deleting an overextracted portion is added. According to this embodiment, it is possible to extract colors with higher accuracy. Less than,
The processes (1) to (14) shown in FIG. 6 will be described.

The processes (1) to (7) are the same as the processes described in FIG. (8) Ask the operator whether there is too much extraction, and if there is not too much extraction, end the process. If there is too much extraction, proceed to processing (9).

(9) In the color image of the extraction result displayed on the display, the operator is made to instruct one or more points of the area to be removed from the extraction target image with a mouse or a light pen.

(10) Based on the designated points, some points (for example, a bright place, a dark place, an intermediate brightness, etc.) are selected as representative points and determined. This selection method may be the same as the selection method of the representative points of the extraction area.

(11) The operator designates the size of the three-dimensional solid which is the range defining the area in the color space, and the size of the deletion range is defined in the color space. (12) A region centered on the color of the representative point in the color space is defined, and the corresponding image data part is removed from the image data of the extraction result.

(13) The image data resulting from the deletion is displayed on the color display 13. (14) Ask the operator to confirm, and if the operator is satisfied with the result of deletion, the extraction process is terminated. If not satisfied, the process returns to the processing (11), the deletion range is changed, and the deletion processing and the deletion result are displayed again. The above process is repeated until the input instruction is satisfied with the result.

As described above, the procedure for deleting data is the same as in the case of extraction, in which the operator designates a representative point of the unnecessary area on the monitor of the color display 13, and the point is used as the center of the area in the color space in a three-dimensional manner. Is specified, and the data contained therein is deleted from the data of the extraction result.

FIG. 7 is an explanatory diagram of a modification example of the extraction result according to the embodiment of the present invention. In FIG. 7, 70 is the display screen of the color display 13, 71 is a small area indicating the range of the area to be deleted on the screen, A is the image to be extracted, B1 and B2 are the unextracted portions, and C1 to C3 are overextracted. Represents a part.

In the method of deleting data from the extraction result shown in FIG. 6, when the extraction range is widened, there is no extraction left, but overextraction occurs conversely, and high-precision extraction is impossible. It is effective in all cases. In the extraction, by specifying the extraction area a little wider, eliminating the remaining portions B1 and B2 to be extracted and deleting the overextracted portions C1 to C3, high-precision extraction can be realized.

Further, as shown in FIG. 7, a small area 71 to be deleted can be designated for a part of the entire surface of the image, and only the image data of the part can be designated as shown in FIG.
Deletion process (representative color designation and data deletion) described in
By doing so, it is possible to delete the data with even higher accuracy and further improve the accuracy of the extraction process.

[0051]

As described above, according to the present invention,
In addition to the advantage that the representative color can be specified and the extraction range can be set easily, there is an advantage that the extraction accuracy can be improved. Furthermore, if the operator sees and leaves an unextracted part, he or she can specify the representative color of the unnecessary part and delete the unnecessary part from the extraction result in the same way as the extraction, so it is easy and easy to operate, and more It is possible to realize an image processing device in which the extraction accuracy is further improved.

[Brief description of drawings]

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

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

FIG. 3 is an explanatory diagram of extraction processing according to the embodiment of this invention.

FIG. 4 is an explanatory diagram of determining representative points according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram of extraction by a plurality of solids according to the embodiment of the present invention.

FIG. 6 is a diagram showing a processing flow in which data deletion is added according to an embodiment of the present invention.

FIG. 7 is a diagram illustrating a modification example of the extraction result according to the embodiment of this invention.

[Explanation of symbols]

 10 Computer 11 Image Input Device 12 Position Input Device 13 Color Display 14 Image Holding Memory 15 Representative Point Determining Section 16 Range Indication Input Section 17 Color Extracting Section 18 Data Deleting Section 19 Display Memory 20 Cursor

Claims (3)

[Claims] 1. A computer (10) for processing image data, a color display (13), and a position input device (12) for inputting a position on a display screen, which are displayed on the color display (13). In a color image color extracting device for extracting a range of the color by specifying a color in the color image by the position input device (12), an image holding memory (14) for holding image data to be a color extraction target. ) And a point in the area to be extracted on the display screen or in the area to be deleted from the extracted image by the position input device (12) to input, and a representative point determining means for determining a plurality of representative points based on the input (15), a range designating input means (16) for inputting a parameter designating a range of colors to be extracted or deleted, and a parameter designating a color of a representative point of the extraction region and a range of the color to be extracted. From the image of the extraction result by the color extraction means (17) for selecting the image data of the color to be extracted from the image holding memory (14), and the parameter that specifies the representative point of the deletion area and the range of the color to be deleted. Data deletion means to remove the image data of the color to be deleted (18)
And a color image extracting device for a color image. 2. A computer (10) for processing image data causes a point of an extraction target area in a color image displayed on a color display (13) to be designated, a representative color of the point is determined, and the color is determined. In the color extraction method of the color image for extracting the range, a process of displaying the color image to be extracted on the display, and a process of indicating and inputting one or more points of the region to be extracted in the displayed image. ， The process of selecting a plurality of representative points from the area that includes the designated points, and a solid with a predetermined size or a specified size in the color space centered on the colors of the selected plurality of representative points And a step of extracting image data of an area having a contained color. 3. A computer (10) for processing image data specifies a point of an extraction target area in a color image displayed on a color display (13), determines a representative color of the point, and determines the color. In the color extraction method of the color image for extracting the range, the process of displaying the color image to be extracted on the display and the process of instructing and inputting one or more points of the region to be extracted in the displayed image. ， The process of selecting a plurality of representative points from the area that includes the designated points, and a solid with a predetermined size or a specified size in the color space centered on the colors of the selected plurality of representative points The process of extracting the image data of the region having the included color, the process of displaying the portion of the extracted image data on the display in a manner that the range can be understood, and one or more points of the region to be deleted from the extraction target. And inputting, selecting a plurality of representative points from the area including the point designated as a deletion target, and a predetermined size in the color space centered on the colors of the selected plurality of representative points. Or a step of removing image data of a region having a color included in a solid having a specified size from the previously extracted image data, a color extracting method of a color image.