JPS63285585A - Color converter for graphic display - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a circuit for generating color signals in a raster scan type color graphic display device.

[Summary of the invention]

In the circuit that generates the color signal, the pixel data input section has a parallel-to-serial converter and a color conversion table divided into three primary colors, and the input data of each table is input to the parallel-to-serial converter. Enter the output of 3 or input the data before conversion.
Switch whether to enter the data separately. Equipped with a switch, it is configured so that it can be used by switching between normal color and multicolor display.

[Conventional technology]

Graph ink display devices can be roughly divided into (at) devices used to display and edit geometric figures, mainly line figures, in the graphic processing field.

(b1 For displaying image information in the field of image processing, etc.)

There are two types.

The requirements for the above two types of graphic displays are as follows: (At for graphic processing, the resolution must be high, but the number of colors that can be expressed simultaneously can be small.

(2) For image processing, the resolution may be low, but the number of colors that can be expressed simultaneously must be large.

As such, they are contradictory. Looking at the simultaneous display colors of existing devices, for fat graphic processing, any 256 colors out of 2 t4 (-16777216) colors can be displayed simultaneously.

The highest standard for image processing is the ability to display 224 colors simultaneously.

In conventional graphic display devices, the above f
an, (bl specifications are realized with different hardware.

In other words, the color converter used in the above (al) device has a color conversion table that converts a color specification code, which is image data, into luminance values of red, blue, and green, which are the three primary colors, and the luminance It consisted of a D/A converter that converts the values into color video signals.In this case, the colors displayed simultaneously are determined by the number of nodes included in the color conversion table.

Further, the color converter used in the fbl device does not have the color conversion table and is composed only of a D/A converter.

In this case, the image data is red.

The brightness values of blue and green are written, and the simultaneous display colors are determined by the number of bits of image data per pixel.

[Problem that the invention seeks to solve]

Using the above (al as a mountain), in order to display 224 colors at the same time, 224 tables must be prepared, but a circuit that can be accessed at a high-speed video signal rate would require an enormous circuit scale, making it difficult to realize in reality. Not the point.

Moreover, if the above (bl) is used as a fan, it is not economical because more information than necessary is held as an image memory.

Therefore, an object of the present invention is to provide a color converter for realizing the above-mentioned two types of conflicting requirements with the same hardware.

[Means for solving problems]

In order to solve the above problems, the present invention includes a parallel-serial converter for the pixel data input section, a color conversion table divided into three primary colors, and a color conversion table for each input data of the color conversion table. , has a switch for switching between inputting the parallel-serial data or inputting the pre-conversion data divided into three parts.

[Effect]

In the case of the normal mode, the axn-bit image data input to this device becomes n-bit data by the parallel-to-serial converter, passes through the switch, and is converted to n-bit data by the parallel-serial converter.
The information is input into two color conversion tables and converted into luminance information of three primary colors. In this case, the number of colors displayed simultaneously is 2''.

In the case of multicolor mode, 3xn bit data of the axn bit data input to the device is divided into three parts, passed through the switch, and inputted separately to the three color conversion tables, It is converted into luminance information of three primary colors. In this case, the number of colors displayed simultaneously is 2311 colors.

〔Example〕

Hereinafter, the present invention will be explained based on illustrated embodiments. 1st
2 are block diagrams for explaining one embodiment of the present invention.

FIG. 2 shows a display section of a graphic display device, and FIG. 1 shows an embodiment of the present invention, and shows the internal configuration of the color conversion circuit 10 in FIG. be.

In this embodiment, the procedure for displaying an image will be explained with reference to FIG. 2. The address 41 of the image memory to be displayed is generated from the +11 display timing generation circuit 40.

(2) 8-bit data 31, 3 corresponding to address 41
2°33 is output from the image memory 30, and the color converter 10
given to. After this, the explanation will be continued according to FIG. 1. (3) The display mode switching failure signal 42 causes the switch 12
13. If 14 is on the input side, the 8-bit data 31,3 given to the parallel-serial converter 11
The total 24-bit data of 2.33 is converted into 8-bit color code data 51.

(4) The color code data passed through the switch 12, 13, 14 is given as a color conversion table address 51, 52, 53, and the brightness value of red is 55 and the brightness value of blue is determined by color conversion table 15, 16, 17, respectively. 56, and is converted into a green luminance value 57.

(5) Each luminance value 55, 56.57 is converted into an analog color video signal 6162.63 by a respective D/A converter.

(6) The color display monitor 60 displays the color video signals 61, 62, and 63 as images on the screen.

In the case of the procedure from fil to (6), since the color code is 8 beats/beat, up to 2" (=256) colors can be displayed simultaneously, and by rewriting the color conversion table, for each color code value, 2” (=16777216) Any one color can be displayed in the package.

(3') The display mode switching signal 42 causes the switch 42 to
is on the B input side, the data 31, 32, and 33 obtained from the image memory pass through the switch 12, 13, and 14, and are sent to the color conversion table 15 as color conversion table addresses 52, 53, and 54, respectively. ．．
16.17, and are converted into a red brightness value 55, a helmet brightness value 56, and a green brightness value 57, respectively.

+11. (21, (3'), (4'), (51,
(In the case of step 61, 224 (=16777216) colors can be displayed simultaneously.

However, if you want to change the display color arbitrarily, you need to rewrite the image memory. Further, if the image memory read cycle is the same, the resolution will be reduced to 1/3, but if the same resolution is required, the read cycle can be tripled in the display timing generation circuit 40.

〔Effect of the invention〕

As described above, by using the present invention, a graph ink display device capable of displaying two types of simultaneous display, normal color and multicolor, can be constructed at low cost using the same hardware. It can be applied to the following fields.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the present invention, and FIG. 2 is a diagram showing a graphic display device using the present invention. 10... Color converter 11 of the present invention... Parallel-serial converters 12 to 14...
...Switchers 15-17...Color conversion tables 18-20...D/A converter 30...Image memory 31-33...Image data 40...Display timing generation circuit 41...
Display address 42...Display mode switching signal 43...Pixel clock 51...Color code data 52.53.54...Color conversion table address 55-5
7... Brightness value 60... Color display monitor 61-63.
・・Color video signal Above is the 7th Uhui・Nfuhi Suai set for the tree starting month and the use, ■Aro 1, 7 Figure 2

Claims (1)

[Claims] A color converter for a raster scanning color graphic display device, comprising a parallel-to-serial converter in a pixel data input section, and a color conversion table divided into three primary colors, each table A switch is provided to switch between inputting the output of the parallel-to-serial converter or inputting the data before conversion into three parts as the input data, and simultaneously switching the display colors according to the display mode. A color converter for graphic displays characterized by: