JPH09218675A - Display control device and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a conversion time required when full color image data are displayed on a multi-color display. SOLUTION: A microprocessor 11 generates palette information to make full colors converted into prescribed kinds of colors by using reduced screen data of full color standard screen data stored on a hard disk 14 and outputs it to CRT controller 15. Also, the microprocessor 11 reads the full color standard screen data from hard disk 14 and outputs them to CRT controller 15. The CRT controller 15 generates color screen data of prescribed kinds of colors from the full color standard screen data and converts the palette information into RGB codes before outputting them to CRT 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display control device and a display control method, and more particularly to generating palette information based on full-color image data of a reduced screen and using the palette information to generate full-color image data. The present invention relates to a display control device and a display control method for converting into multicolor image data.

[0002]

2. Description of the Related Art Conventionally, when displaying an image of full-color image data on a multi-color compatible display in which the types of colors that can be displayed at one time are limited, the full-color image data is composed of only a predetermined type of color. Technology for converting to color image data and displaying it has been realized.

In this conversion, R (Red), G (Green), B (B
The frequency of occurrence of N colors specified by each value of lue) is statistically processed, the number of colors with high frequency of occurrence is determined by a predetermined number (n), and N colors included in the full-color image are determined. Is converted into any one of the n colors of the multi-color image that is as close as possible.

In this way, a full-color image can be displayed on a multi-color compatible display.

[0005]

However, when the conversion is performed in this way, it is necessary to execute the above-described statistical processing on all the pixels that make up the full-color image. In the case of a full-color image, since one pixel has a data amount of 1 byte (256 gradations) for each of R, G, and B, the total data amount is 3 bytes. Therefore, for example, when the size of one screen (one frame) of the VGA (Video Graphics Array) standard is 640 horizontal pixels * 480 vertical pixels,
To convert one frame, about 1M bytes (640 * 4)
It is necessary to perform the above statistical processing on 80 * 3 bytes of data.

As described above, when a full-color image is displayed on a multi-color display device, a relatively large amount of data is processed in the process, which requires time for calculation, and as a result, a video signal is displayed on the display device. There is a problem that it takes time from the input to the display of the target image. In addition, there is a problem that it is difficult to obtain a sufficient response especially when processing a moving image.

The present invention has been made in view of the above circumstances, and is intended to reduce the calculation time required for conversion by using image data of a reduced screen of a full-color image for conversion. .

[0008]

According to another aspect of the present invention, there is provided a display control device comprising: a first color image data of a first screen having a predetermined size; and a second color image having a size reduced from the first screen. Storage means for storing the first color image data of the second screen, and palette information indicating a correspondence relationship between the color of the first color image data of the second screen and the color of the second color image data. By using the generation means to generate and the generated palette information,
And a conversion unit that converts the first color image data into the second color image data.

According to another aspect of the display control method, the first color image data of the first screen having a predetermined size and the first color image data of the first screen are used.
The first color image data of the second screen having a reduced size of the second screen, and the correspondence between the color of the first color image data of the second screen and the color of the second color image data. It is characterized in that palette information indicating the relationship is generated and the first color image data is converted into the second color image data by using the generated palette information.

In the display control apparatus according to the first aspect, the storage means stores the first color image data of the first screen having a predetermined size and the second color image having a reduced size of the first screen.
Of the first color image data of the second screen and the generation means stores the color of the first color image data of the second screen and the second color image data of the second color image data.
The palette information indicating the correspondence with the color of the color image data is generated, and the conversion means converts the first color image data into the second color image data using the generated palette information.

In the display control method according to the second aspect, the first color image data of the first screen having a predetermined size and the first color image of the second screen having a reduced size of the first screen.
Color image data of the second screen is stored, palette information indicating a correspondence relationship between the color of the first color image data on the second screen and the color of the second color image data is generated, and the generated palette information is generated. It is used to convert the first color image data into the second color image data.

[0012]

1 is a block diagram showing the configuration of an embodiment of a personal computer to which the display control device of the present invention is applied.

The microprocessor 11 (generation means) is
When the power is turned on, the control program is read from the ROM 12 and various controls of the personal computer 1 are performed.

An instruction signal by the user operating the mouse 13 is input to the microprocessor 11.

In the hard disk 14 (storage means), in addition to image processing software, full-color image data (standard screen data) of a screen (standard screen) of a predetermined size used by the software, and the standard screen. The full-color image data (reduced screen data) of the reduced screen whose size is reduced is stored. This reduced screen data is for displaying as an index when a predetermined one of a plurality of standard screens is selected.

When there is no reduced screen data corresponding to the standard screen data in the hard disk 14, the microprocessor 11 generates the reduced screen data based on the standard screen data, if necessary. .

Further, the microprocessor 11 performs statistical processing on color information for all pixels constituting the full-color reduced screen, determines a predetermined color by the number of colors that can be displayed at one time by the CRT 16, and determines both. The palette information indicating the correspondence relationship of the colors of the CRT controller 15
It is designed to output to.

The CRT controller 15 (conversion means) is
Based on the palette information and full-color image data input from the microprocessor 11, color image data of a predetermined type of color (a color that can be displayed at one time) is generated, converted into RGB signals, and then output to the CRT 16. Has been done.

The RAM 17 is used as an area in which running software is made resident, or used as a swap memory or a work memory.

The scanner 18 is adapted to convert a full color image such as a photograph into full color image data and output it to the microprocessor 11.

Next, with reference to the flow chart of FIG. 2, a description will be given of the data addition processing to the database that stores the full-color data of the standard screen and the reduced screen used in the display control device of the present invention.

In step S1 in FIG. 2, the user inputs full-color image data such as a photograph into the microprocessor 11 by operating the scanner 18 by using predetermined image processing software. The microprocessor 11
The full-color image data is stored in the hard disk 14 as standard screen data.

At the subsequent step S2, the microprocessor 11 may have newly input the standard screen data, or may have already registered the image processing software (registered as sample data). To determine if. That is, it is determined whether or not reduced screen data corresponding to the standard screen data is already stored in the hard disk 14.

In the present case, the standard screen data is the scanner 1
Since it was newly input by the operation of 8, N
When it is determined to be O, the microprocessor 11 generates reduced screen data corresponding to the standard screen data and stores it in the hard disk 14 in step S3.

An example of a reduced screen based on the reduced screen data generated at this time is shown in the reduced screen G11 of FIG.

As shown in FIG. 3, the reduced screen G11 is a reduced screen of the full-color standard screen G1. Assuming that the standard screen G1 is composed of 640 horizontal pixels * 480 vertical pixels, for example, the reduced screen G11 has horizontal and vertical directions.
It is composed of 1/8 of the horizontal 80 pixels * vertical 60 pixels. That is, in the present example, 64 pixels of the standard screen G1
Full-color reduced screen data is generated so that (horizontal 8 pixels * vertical 8 pixels) corresponds to one pixel of the reduced screen G11.

In this way, the newly input standard screen data and the corresponding reduced screen data are stored in the hard disk 14.

Next, it is assumed that the user has operated the mouse 13 to display a predetermined image stored in the hard disk 14. The processing operation of the personal computer 1 at this time will be described with reference to the flowchart of FIG.

In step S11 of FIG. 4, when the microprocessor 11 receives the input of the instruction signal by the user's predetermined operation of the mouse 13, the microprocessor 11 displays an index screen for allowing the user to select a predetermined image. A predetermined number of reduced screen data are read from the hard disk 14 according to the recording order or the file name order.

In the following step S12, the microprocessor 11 performs statistical processing on color information for all the pixels forming the reduced screen data to generate palette information for converting full color into a predetermined type of color.

Here, the details of the process of step S12 will be described in more detail with reference to FIGS.

Since any color is uniquely determined by determining the respective values of R, G, B, one point in the three-dimensional space represented by the orthogonal coordinates of R, G, B corresponds to one color. Will be done. Therefore, when statistically processing the frequency of occurrence of colors for all the pixels forming the screen, it is necessary to consider it in three dimensions. However, for simplification, the case of one dimension will be described with reference to FIGS. Considering now, let us now consider the two-dimensional case with reference to FIGS.

FIG. 5 shows a plot of the occurrence frequency of any one of R, G, and B at 256 gradations for all the pixels constituting the full-color reduced screen.

An example of a method for associating all of these pixels with any one of predetermined gradation values, for example, eight gradation values will be described with reference to FIG.

FIG. 6 shows a state in which the area surrounded by the horizontal axis and the graph in the graph shown in FIG. 5 is divided into eight equal parts.

In this way, since these areas are equal, the number of pixels included in each area is also equal.

Here, in these 8 divided areas,
Level L is the intermediate value of the values that make up the area with the lowest value
Let it be 1. In this way, the intermediate values of the values forming each of the eight equally divided areas shown in FIG. 6 are, in order from the left, level L1, level L2, level L3, level 4, level L5, level L6, and level L7. , And level 8,
The eight gradation levels are determined as these levels L1 to L8.

Pixels included in each area divided into eight equal parts have these levels (any one of levels L1 to L8) included in each area.
Correspond to. For example, as shown in FIG.
All pixels having a value of level LX are converted as being at level L8. In this way, palette information for converting the value of 256 gradations into the value of a predetermined number (8 gradations) is generated.

In this way, since the number of pixels having the values of level L1 to level L8 is the same, uniform and even values can be selected, and a good quality conversion screen can be obtained.

Next, FIGS. 7 and 8 for the two-dimensional case.
This will be described with reference to FIG.

FIG. 7 shows two-dimensional (for example, R and G values) for all the pixels that make up a full-color reduced screen.
5 is plotted in the same manner as in the case of FIG.

Also in this case, as in the case of FIG. 6, a predetermined number of areas are determined so that the same number of pixels are included in each area. In the case of two dimensions, this area has a meaning of a planar spread, so that it is desirable to make it a square area.

First, as shown in FIG. 7, the entire area is divided into four square areas, area A, area B, area C, and area D. Then, the number of pixels included in each area is compared, and an area including many pixels is further divided into four equal parts. In this case, since the number of pixels included in the area C is large,
Region C is divided into four equal parts.

The state at this time is shown in FIG. In the example shown in FIG. 8, the region C shown in FIG. 7 is further divided into regions C1 and C.
2, the area C3, and the area C4.

In this way, the number of pixels included in each area is compared, the area having a large number of pixels is further divided into four square areas, and all the divided areas are divided into respective areas. Compare the number of included pixels. The above processing is repeated until the entire area is divided into a predetermined number of areas.

In the example shown in FIG. 8, each area (area A, area B, area D, area C1, area C2, area C2, or area C4) contains three or four pixels, respectively. Has become.

Now, assuming that the predetermined gradation is 7, FIG.
The full color can be converted into seven types of colors by using the palette information shown in. In this case, all the pixels included in each area are converted into the same color as the color indicated by the center of each area (point indicated by x in the figure).

In this manner, all the pixels forming the image are statistically processed, and a predetermined number of colors having a small number of pixel biases are determined to generate palette information for converting full color into a predetermined color. (The above discussion is the same for the three-dimensional case, and for the three-dimensional case,
The space represented by the Cartesian coordinates of the three axes of R, G, and B is divided by a cube).

Returning to the explanation of the flowchart in FIG. 4, the microprocessor 11 outputs the generated palette information to the CRT controller 15 in step S13.

In the following step S14, the CRT controller 15 uses this palette information to generate the video data of the reduced screen constituting the index screen, and the CRT1
6 is output. FIG. 9 shows a display example of the index screen displayed on the CRT 16 in this manner.

On the screen shown in FIG. 9, six reduced screens and a cursor C are displayed, and the user can select a desired image (standard screen) on this screen. Also,
If the reduced screen corresponding to the target image is not displayed on the CRT 16, operate the mouse 13 to move the cursor C
Is moved to the position of the right arrow R or the left arrow L and left-clicked to scroll the screen in the right direction or the left direction, respectively. As a result, the index screen is updated and the index screen including the new reduced screen is displayed.

In step S15 of FIG. 4, the user determines whether or not the reduced image corresponding to the target image is displayed on the index screen, and determines that the reduced screen corresponding to the target image is not displayed. If yes, step S16
Then, the cursor C is moved to the position of the right arrow R or the left arrow L by operating the mouse 13, and the left click is performed. When the instruction signal corresponding to this operation is input to the microprocessor 11, the microprocessor 11 selects the reduced screen that constitutes the index screen scrolled in the direction corresponding to the operation. Then, the processing from step S11 onward is repeatedly executed again.

In this way, the user can scroll the screen by the above-mentioned operation to display the index screen on which the reduced screen corresponding to the target image is displayed. The reduced screen corresponding to the target image is the CRT16
Is displayed, a NO determination is made in step S15, and in step S17, the user operates the mouse 13 to move the cursor C to the target reduced screen and double-clicks it. Now, at the position of the cursor C shown in FIG.
It is assumed that the user has double-clicked.

When an instruction signal corresponding to this operation is input to the microprocessor 11, at step S18,
From the hard disk 14, the microprocessor 11
The standard screen data corresponding to the selected reduced screen is read and output to the CRT controller 15.

The CRT controller 15 converts the full-color standard screen data into a predetermined type of color image data based on the palette information of the reduced screen, and outputs it to the CRT 16.

FIG. 10 shows a display example of the screen displayed on the CRT 16 in this manner.

The "return" button B in FIG. 10 is a button selected when returning to the index screen shown in FIG.

In this way, since the above palette information is generated based on the reduced screen, the time required for the conversion processing can be shortened. For example, when the display size of the reduced screen is 1/64 of the size of the standard screen, the amount of data statistically processed is 1/64 and the processing time is about 1/64.

Therefore, since the processing time required for the conversion is shortened, it is possible to perform display at a comfortable display speed, particularly when continuously displaying still images or moving images.

Although the display control device of the present invention is applied to the personal computer 1 in the above-described embodiment, the display control device and the personal computer can be separated. Further, the recording medium may be a magnetic disk other than a hard disk, a magneto-optical disk, an optical disk, an IC card, or the like. Further, in the above embodiment,
Although the palette information is obtained for each index, a predetermined number of reduced screens may be sampled and the palette information generated based on the reduced screens may always be used.

[0061]

As described above, according to the display control device of the first aspect and the display control method of the second aspect, the palette information is generated from the first color image data of the second screen. Therefore, when a full-color image is displayed on a multi-color display, a comfortable display speed can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a personal computer 1 using a display control device of the present invention.

FIG. 2 is a flowchart illustrating a processing operation of the personal computer 1 when data is added to a database that stores full-color data of a standard screen and a reduced screen thereof.

FIG. 3 shows a standard screen G1 and a reduced screen G11 which is a reduced version of the standard screen G1.
FIG.

FIG. 4 is a flowchart illustrating a processing operation of the personal computer 1 at the time of image search.

FIG. 5 is a diagram showing a graph in which color information is statistically processed for all pixels forming one image when color information of pixels is one-dimensional information.

FIG. 6 is a diagram showing a method of determining one-dimensional information of a predetermined type from the graph shown in FIG.

FIG. 7 is a diagram showing the color information statistically processed for all the pixels forming one image when the color information of the pixels is two-dimensional information.

FIG. 8 is a diagram showing a method for determining a predetermined type of two-dimensional information from the diagram shown in FIG. 7.

FIG. 9 is a diagram showing a display example of an index screen displayed on the CRT 16.

10 is a diagram showing a display example of a screen displayed on the CRT 16 when the reduced screen at the position of the cursor C in FIG. 9 is selected.

[Explanation of symbols]

1 personal computer, 11 microprocessor, 12 ROM, 13 mouse, 14 hard disk, 15 CRT controller, 16 CR
T, 17 RAM, 18 scanner

Claims (2)

[Claims] 1. A display control apparatus for converting first color image data of more kinds of colors forming an image into second color image data of less kinds of colors, outputting and displaying the converted data. Storage means for storing the first color image data of a first screen having a predetermined size and the first color image data of a second screen having a reduced size of the first screen, A color of the first color image data on the second screen,
The first color image data is converted into the second color image data by using a generation unit that generates palette information indicating a correspondence relationship with the color of the second color image data, and the palette information generated by the generation unit. A display control device comprising: a conversion unit that converts color image data. 2. A display control method for converting first color image data of more kinds of colors forming an image into second color image data of less kinds of colors, outputting and displaying the converted data. Storing the first color image data of a first screen of a predetermined size and the first color image data of a second screen of a reduced size of the first screen, The color of the first color image data on the second screen,
Generating palette information indicating a correspondence relationship with the color of the second color image data, and converting the first color image data into the second color image data by using the generated palette information. A display control method characterized by: