JPH0348553B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image processing device that changes the color, density, etc. of an image displayed on a CRT screen.

(Prior art and its problems) Changing colors has traditionally been a common practice as one of image processing techniques. For example, by changing only the color data of areas corresponding to tree leaves in a landscape image from green to yellow, a new image that is different from the original image is generated. In order to perform this processing, it is sufficient to replace each of the red (RED), green (GREEN), and blue (BLUE) data of each image pixel with different data. However, if it is attempted to rewrite the data of each image pixel each time the color is changed, the number of accesses from processing hardware such as a CPU to the image memory will naturally increase.
For this reason, color change processing by rewriting the image memory inevitably increases processing time. Therefore, frequent color change processing is not suitable for systems that require high-speed response, high resolution, or extremely large storage capacity of image memory.
Therefore, the help of specially configured hardware (for example, a processor dedicated to image processing) is required.
Eventually, the hardware systems became more complex and the programming became more specialized.

Furthermore, in the process of changing the color by rewriting the image memory, once the image data is changed, the original data is erased. Therefore, it is not suitable for a system in which the original color and the changed color are frequently compared, such as in a color change simulation.

From this point of view, the inventors of the present application created the image processing device described below. FIG. 9 shows a block diagram of a part of the image processing apparatus.

1 is a logical image memory, and 2 is an image memory in which density information provided corresponding to R (red), G (green), and B (blue) is stored. 3 is a lookup table, and 4 is a D/A converter. The logical image memory 1 and image memory 2 are accessed from the microprocessor 5 through the bus 8. Reference numeral 6 denotes a main memory of this microprocessor 5. The output (video analog signal) of the D/A converter 4 is sent to a CRT for image display. The lookup table 3 is a type of arithmetic unit, and is composed of a static RAM capable of high-speed signal processing. The data output from the image memory 2 and the wheel image memory 1 are combined to form an address signal for the lookup table 3. For example, the capacity of lookup table 3 is 256
It is a byte and converts 256 types of information into separate information (8 bits). With this device, the color can be changed by simply changing the contents of the lookup table 3 without changing the contents of the image memory 2. Furthermore, by storing information on switching the lookup table 3 in the logical image memory 1 and switching the lookup table 3, it is possible to change the color selection of only a specific portion of the image. The output of lookup table 3 is passed through latch 7.
Sent to CRT. The lookup table 3 is connected to the microprocessor 5 via a gate 9 and a bus 8.
The contents are set by .

Now, in this conventional method, a logical image memory 1 is required in addition to the image memory, which has the disadvantage that the system becomes large-scale. Furthermore, a method for changing the color of multiple areas at the same time has not been disclosed.

An object of the present invention has been made in view of the above-mentioned conventional problems, and it is an object of the present invention to provide a system that can quickly change the color of multiple areas in an image without having a special logical image memory. be.

(Means for solving the problem) By the way, in recent years, with the reduction in the price of image memory, it has become common to store image information in memory and perform image processing and output. The amount of information required per dot varies depending on the type of image. For example, for an image such as a black and white print, 1-bit information indicating whether it is white or black is sufficient, and for an image such as a traffic sign, 3 to 4 bits of information may be sufficient because the number of colors is red, white, yellow, green, blue, etc. Although the number of colors increases in images such as animation cels, since the colors can be painted solidly, information on shading is not necessary and the amount of information may be about 5 to 7 bits.
However, when expressing natural images such as photographs and television images, about 18 bits are required.

On the other hand, from the perspective of image processing, it is desirable that the amount of information per dot in the image memory be a multiple of 8, since a typical microprocessor processes 8 or 16 bits. For example, input a color natural image,
For example, in an image processing device, when color information is separated into R, G, and B and stored in an image memory, R,
The amount of information of 8 bits each for G and B, totaling 24 bits, is 1
A device held around a dot could be considered. When such a device stores various images as described above, there is a difference between the amount of information held by the image and the amount of information in the image memory, resulting in waste of capacity of the image memory.

Next, when changing the color of specific areas in an image, the number of areas varies depending on the case. For example, in an image of a kimono, you often want to change the two colors of the kimono's background and obi, and in animation cels, you often want to change the colors at the same time for each type of paint used in that screen. many. In order to make different color changes in multiple locations, it is necessary to label the regions, but the amount of information required for labeling varies depending on the subject of the image.

The above can be summarized as follows.

The amount of information per dot of an image varies depending on the object.

The amount of information per dot in the image memory is preferably a multiple of 8.

The amount of information in an image label varies depending on the object.

The present invention has been made by focusing on the above-mentioned points. To summarize, the present invention can be summarized as follows: density data of each pixel constituting an image and label data for identifying a pixel corresponding to an area where this density data is to be changed. A density label memory that stores data as a single piece of data having a predetermined data length set in accordance with the amount of information contained in an image, and output data from this density label memory are introduced, and the density data can be stored as one piece of data. A lookup table that changes and outputs the density data of pixels corresponding to the area to be changed;
A display device for displaying an image based on the output of the lookup table and a device for writing label information into the density label memory, and changing and coloring an area of the image corresponding to the set label. This is an image processing device characterized by: That is, the present invention uses a density label dual-purpose memory that has the functions of both an image memory and a label information memory to improve memory usage efficiency.

(Function) In the present invention, the density label memory can store both image information and label information.
For example, if the density label memory is composed of m x n x 8k bits (mn is the vertical and horizontal resolution of the image, and k is an integer), when the image information is i bits, the label information is stored in the density label memory. It is stored in the wasted part of 8k-i bits. As a result, if the amount of information per dot in the image is small, the amount of information in the label can be increased, and the optimal combination of image and label information can be selected, making the density label memory more effective. can be used.

(Example) Hereinafter, an example of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows an apparatus equipped with an 8-bit density label memory 22 for each of red (R), green (G), and blue (B) data. The output D24 of the density label memory 22 is connected to the address of the lookup table 23.
The output of
Connected to 4. In this example, the output of the lookup table 23 is 8 bits each for R, G, and B (0 to 255).
It is.

The output (video analog signal) of the D/A converter 24 is sent to the CRT for image display. The concentration label memory 22 and the main memory 26 are connected to the microprocessor 2 through a bus 28.
Accessed from 5. Lookup table 2
3 is accessed from the microprocessor 25 through the gate 29 and the bus 28.

Next, the processing of this device will be explained. First, an image is transferred to the density label memory 22 using a scanner, a TV camera, etc.
Enter 2. At this stage, the density label memory 22 stores information of 8 bits each of R, G, and B for each dot. However, as mentioned above, the amount of information required per dot is actually smaller than 8 bits, and varies depending on the type of image. For example, if you want to change the background and color of the obi of a kimono, it is sufficient to have 6 bits each of R, G, and B image information. Therefore, the density label memory 2
The upper 6 bits of 2 are used for image information, and the lower 2 bits are used for storing label information. FIG. 2 shows an example in which 6 bits are used for image information and 2 bits are used for label information. In this case, the image information i per color can take the range 0≦i<2 ⁶ , the label information l can take the range 0≦l<2 ² , and the output of the density label memory 22 is 2 ² ×i + l. Become. FIG. 3 shows an example of label information memory divided into areas. In the label information memory, the same numerical values for R, G, and B are stored, for example, l=1 for the area of the kimono, l=2 for the obi area, and l=0 for the other areas. Write using a processor. The method for writing this data is, for example, to display a cursor on the CRT, write each numerical value corresponding to that cursor into the label information memory, and then move the cursor over the kimono ground area or obi area. There is a method of moving the top and writing a numerical value corresponding to the area into the label information memory.

Next, we will show how to actually change the color.

The output of the density label memory 22 is 2 ² ×i+l
The case where l=0 is the background, the case where l=1 is the kimono ground area, and the case where l=2 is the obi area, so each lookup table 23 for R, G, and B is
When the address of is 2 ² ×i′+l′ (0≦i′<2 ⁶ , 0
≦l′<2 ² ), by changing the lookup table 23 with the address l′=1, it is possible to change only the color of the background of the kimono; By changing 23, only the color of the band can be changed.

FIG. 4 shows an example of the lookup table 23 for changing the background color (l'=1) of a kimono to a brighter color and the obi (l'=2) darker.

Next, an example of coloring animation cels will be shown.

The original drawing shall be a line drawing as shown in FIG. As in the kimono example, first, an image is input to the density label memory 22 using a scanner, a TV camera, or the like. At this stage, the density label memory 22 can store information for each of 8 R, G, and B dots per dot. However, in the case of line drawings, one bit is sufficient for the amount of information per dot. Therefore, the upper bits of the density label memory 22 are used for image information.
The lower 7 bits are used to store label information. R,
To create image information of 1 bit each for R, G, and B from shading information of 8 bits each for G and B, since the original image is a black and white image, it is only necessary to set an appropriate threshold value and perform binarization. . FIG. 6 shows an example of the density label memory 22 in which the upper 1 bit is set for image information and the lower 7 bits are set for label information. In this case R,
The image information i for each color of G and B is i=0 and 1, where l=0 corresponds to a black line and i=1 corresponds to a white background area, for example. Further, the label information l can take a range of 0≦l< ²⁷ . As a result, the output of the density label memory 22 becomes 2 ⁷ ×i+l. A microprocessor is used to write the same numerical value for each of R, G, and B in the label information memory. A possible method for writing label information is to fill in the line drawings stored in the image information memory. FIG. 7 shows an example of label information memory divided into areas. In this example, 13 areas are set.

Next, we will show how to actually color the image after performing the above processing. The output of the concentration label memory is 2 ⁷ ×i
+l, and since the area with i=1 is the white part of the background, let the label number of the area you want to color be l'(0≦l''<127) and each R whose address is 2 ⁷ +l'',
If you set the contents of the lookup table 23 for G and B to the desired color, the area labeled l'' will be colored.The output of the lookup table 23 will be R,
Since G and B are each 8 bits, ²²⁴ colors can be displayed. Furthermore, the data written to the lookup table 23 is only one byte of numerical value each for R, G, and B, and the processing speed is very high. Select l″ appropriately, R,
By simply writing 3 bytes of color data into each of the G and B lookup tables 23, coloring can be done quickly and freely. FIG. 8 shows an example of the lookup table 23 that colors areas with label numbers 1, 2, and 3 in red, blue, and green, respectively. Also, the data from address φ to ^27-1 in the lookup table 23 corresponds to the line area, so if you want to make it a black line, all the data is 0.
Just leave it as .

(Effects of the Invention) As is clear from the above description, the apparatus of the present invention uses a dual-purpose memory that can be used as both an image memory and a label information storage memory, so that it can process image shading information according to the type of input image. It is possible to increase the number of labels, increase the number of labels, use memory freely and efficiently, reduce the scale of the system, and create a low-cost image processing device. Furthermore, since a lookup table that can be rewritten at high speed is used, it is possible to quickly change the color of a plurality of areas according to the set number of labels.

Note that in this embodiment, the color information is R, G, B.
Although we have taken as an example a device that separates and stores the three primary colors, it is also applicable to devices that use other color separations such as luminance and color difference.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a part of the image processing apparatus according to the present invention, FIG. 2 is an explanatory diagram of a density label memory used in one embodiment of the image processing apparatus of FIG. 1, and FIG. 4 is an explanatory diagram of the label information of one processed image in the density label memory, FIG. 4 is a characteristic diagram of the lookup table used in the above embodiment of the image processing apparatus of FIG. 1, and FIG. 6 is an explanatory diagram of another processed image. FIG. 6 is an explanatory diagram of the density label memory used in another embodiment of the image processing apparatus shown in FIG. 1. FIG. FIG. 5 is an explanatory diagram of label information of a processed image, FIG. 8 is a characteristic diagram of a lookup table used in the embodiment of FIG. 6, and FIG. 9 is a block diagram of a part of a conventional image processing device. be. 1...Logical image memory, 2...Image memory, 3
...Lookup table, 4...D/A converter, 5...Processor, 6...Main memory, 7...
... Latch circuit, 22 ... Label memory, 23
...Lookup table, 24...D/A converter, 25...Processor, 26...Main memory section, 27...Latch circuit.

Claims (1)

[Claims] 1 The image has density data of each pixel constituting the image and label data for identifying the pixel corresponding to the area where this density data is to be changed, each having a predetermined data length set in accordance with the amount of information contained in the image. A density label memory that stores the data as one data, a lookup table that changes and outputs the density data of pixels corresponding to the area where the density data is to be changed, and a lookup table that changes and outputs the density data of pixels corresponding to the area where the density data is to be changed is introduced. It is equipped with a display means for displaying an image based on the output of the lookup table and a means for writing label information into the density label memory, and is capable of changing and coloring an area of the image corresponding to a set label. Characteristic image processing device.