JPH05298443A - Color picture area extracting device - Google Patents

Abstract

PURPOSE:To stably extract a specified color area without being influenced by the variation of the level of brightness on the basis of the picture data of three colors, red, green and blue obtained from the signal of a CCD camera, etc., and in addition, to extract it even without converting into saturation, lightness and chromaticity. CONSTITUTION:This color picture area extracting device is constituted of a comparison circuit 1 which compares color picture data RD, GD, BD of three colors red, green and blue, and outputs maximum value data MD among them, normalization circuits 21 to 23 which obtain color picture normalized data RA, GA, BA by dividing the color picture data RD, GD, BD of three colors by the maximum value data MD from the comparison circuit 1, and a CPI 4 which obtains the sum of squares of the differences of the color picture normalized data corresponding to each picture element and the neighboring picture element, and divides the area by labeling it on the basis of the obtained sum of squares of the differences, and compares the mean value of the color picture normalized data of three colors of each area with the color picture normalized data of the color to be extracted, and extracts the area of the color close to it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for extracting a specific color area using red, green and blue color image data.

[0002]

2. Description of the Related Art Conventionally, in the case of extracting a region of a specific color based on color information obtained by processing a color image from a CCD camera or the like, three colors of red, green and blue in the entire image are extracted. The color image data is a method of selecting pixels in a predetermined range and extracting an area, or converting the red, green, and blue color image data of each pixel into saturation, brightness, and chromaticity. Saturation, brightness of the color to be extracted,
A method of obtaining a color difference between each pixel and a color to be extracted from the chromaticity and the saturation, lightness, and chromaticity of each pixel, selecting a pixel having a color difference within a predetermined range, and extracting an area is used.

[0003]

However, in the former method of the related art, the size of the color image data of three colors of red, green, and blue is the same although the brightness level changes depending on the image. It will go up and down in proportion to each other and it will not be possible to judge the same color.

Further, in the latter method, it is necessary to convert the color image data of three colors of red, green and blue into the saturation, the brightness and the chromaticity and further calculate the chromaticity, which increases the amount of calculation.

Therefore, according to the present invention, when a specific color area is extracted from color image data, the area can be stably extracted even when the brightness level changes, and the three areas of red, green and blue are extracted. The area of a specific color can be extracted from the color image data of a color without converting the saturation, lightness, and chromaticity or obtaining the color difference.

[0006]

According to the present invention, the degree of brightness of the color image data of the three colors is determined for each pixel of the color image data of the three colors of red, green and blue forming a color image. A comparison circuit for obtaining maximum value data corresponding to the indicated lightness, and a normalization circuit for obtaining color image normalized data of three colors by dividing the color image data of the three colors by the maximum value data in order to make the brightness levels uniform. With and
The target color image is divided into two or more areas from the obtained color image normalized data of the three colors, and the average value of the color image normalized data of the three colors is calculated for each of the divided areas. The area of the average value of the color image data of the three colors close to the color image normalized data of the three colors of the predetermined colors to be extracted is selected.

[0007]

In the color image area extracting apparatus of the present invention constructed as described above, the image data of three colors of red, green and blue are stable without being influenced by the change of the brightness level. It is possible to extract a region of a specific color without the need to convert from Saturation, Lightness, Chromaticity or to obtain the color difference.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings.

FIG. 1 is an overall block diagram, 1 is RD, G
Comparing circuits for comparing the color image data of three colors of D and BD and outputting the maximum value data MD among them, 21, 22, 2
3 is color image data RD, GD, BD of 3 colors respectively
Is divided by the maximum value data MD from the comparison circuit 1 to obtain the color image normalized data RA, GA, BA, and the reference numerals 31, 32, 33 indicate the colors from the normalized circuits 21, 22, 23, respectively. Image normalization data RA,
Frame memories for storing GA and BA, 4 are frame memories 31, 3 respectively corresponding to each pixel and neighboring pixels.
Color image normalized data MR stored in 2, 33
The sum of squares of the differences of A, MGA, and MBA is obtained, the obtained sum of squares of the differences is labeled, the region is divided, and the average value of the three color image normalized data of each divided region is obtained. CPU for extracting a region of a similar color by comparing with the color image normalized data of the color to be extracted which is obtained in advance,
Reference numeral 5 is a label image memory which is used for labeling when the area is divided and further stores the final result of the extracted area.

FIG. 2 shows an example of the color image data, where X,
Y represents the coordinate direction. In FIG. 2, there are three different color areas A, B, and C, and the color image data RD, GD, and BD of three colors in one horizontal line Y1 are shown in FIG. In the area A in FIG. 3, the ratio of each of the color image data RD, GD, and BD of the same color, that is, three colors is constant, but the brightness level changes gently.

When the data RD, GD, BD of FIG. 3 are input to the comparison circuit 1, the maximum value data MD becomes the data shown in FIG.

The data RD, GD, and BD are converted into maximum value data M shown in FIG. 4 by the normalization circuits 21, 22, and 23, respectively.
When the divided data is normalized by D, it is 3 shown in FIG. 5, respectively.
It becomes the color image normalization data RA, GA, BA of the color,
These data are respectively stored in the frame memories 31, 32,
It is stored in 33.

The CPU 4 includes frame memories 31, 32,
3 color image normalization data M stored in 33
RA, MGA, and MBA are labeled from the upper left to the lower right of the image by raster scanning.

As a labeling method, each pixel is sequentially numbered from 1, but a new unused number is assigned to the leftmost pixel of the image. Next in image 1
For the pixels other than the leftmost pixel, the read color image normalization data MRA, MGA, MBA and the previous color image normalization data MRA, MG
If the difference between A and MBA is calculated and the sum of squares is smaller than a predetermined threshold value, the same number as that on the left side is given, and if the sum of squares is larger than the threshold value, a new unused sum is used. Number them. The assigned number is stored in the label image memory 5. In the embodiment, the contents of the label image memory 5 are as shown in FIG. Next, the contents of the label image memory 5 obtained are read again by raster scanning, and nothing is done on the top line,
In the second and subsequent lines, the sum of squares is calculated by taking the difference between the color image normalized data MRA, MGA, MBA of each pixel and the color image normalized data MRA, MGA, MBA of the pixel immediately above. If it is smaller than the threshold value, in the entire contents of the label image memory 5, the larger one of the label numbers of the target pixel and the pixel immediately above is replaced with the smaller number. In the embodiment, it can be rewritten as shown in FIG.

Next, the CPU 4 refers to the label image memory 5 for each labeled area, and obtains the average value of the color image normalized data MRA, MGA, MBA of three colors for each area. The sum of squares of the differences between the average values of the three color image normalized data MRA, MGA, and MBA of the respective areas obtained and the respective data of the three color image normalized data of the color to be extracted is calculated and obtained. 2 of the difference for each region
The area of the minimum value in the sum of multiplications is the area to be extracted, and is the area of the corresponding label number in the label image memory 5.

In this way, when a specific color area is extracted using color image data, it can be stably extracted without being affected by changes in brightness level, and red, green, and Extraction can be performed directly from the image data of the three colors of blue.

Note that when labeling is performed, the sum of absolute values of data differences may be used instead of the sum of squares of data differences, and color image normalized data of three colors of a color to be extracted after area division may be used. Instead of bringing the closest area, a threshold value may be set for the color image normalized data of three colors of the color to be extracted, and a plurality of areas within the threshold value may be extracted.

[0018]

According to the present invention, as described above, red,
From the color image data of 3 colors of green and blue, it is stable without being influenced by the change of the brightness level, and moreover, red, green,
It is possible to extract an area of a specific color without the need to convert the color data of the three colors of blue into the saturation, the brightness, and the chromaticity and to obtain the color difference. Moreover, it can be used not only for area extraction but also for inspection of the color code of the resistor and the color of the cable of the connector.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a color image area extraction device of the present invention.

FIG. 2 is a diagram showing an example of color image data.

FIG. 3 is a diagram showing an example of red, green, and blue color image data.

FIG. 4 is a diagram showing an example of maximum value data.

FIG. 5 is a diagram showing an example of color image normalized data of red, green, and blue.

FIG. 6 is a diagram showing internal data of a label image memory.

[Explanation of symbols]

 1 Comparing Circuit 21, 22, 23 Normalizing Circuit 31, 32, 33 Frame Memory 4 CPU 5 Label Image Memory

Claims (1)

[Claims] 1. A comparison circuit for obtaining maximum value data of color image data of three colors of red, green and blue for each pixel,
A normalization circuit for obtaining the color image normalized data of the three colors by dividing the color image data of the three colors for each pixel by the maximum value data. The area is divided into a plurality of areas and the area is selected by selecting an area close to the color image normalized data of three colors of the color to be extracted from the average value of the color image normalized data of the three colors in each area. Color image area extraction device for extraction.