JPS61285489A - Graphic display unit - 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 Industrial Application) The present invention relates to an improvement in graphic display in a raster scan type graphic display. In particular, it relates to a means for making step-like jagged edges (aliasing) that occur in the contours of figures less noticeable.

(Prior Art) In a raster scan type graphic display, when a polygon is displayed on the display screen by filling the inside with a certain color, it is done in a conventional manner.

FIG. 8 is an explanatory diagram showing a case where the inside of a triangle is filled in. The interior of the triangle is filled by performing linear interpolation based on the coordinates of vertices P L, P2, and P3. That is, for example, when filling in point Q, Q
Both end points of the scanning line including PI2. After the coordinates of P23 are determined by proportional calculation regarding the distance from each vertex, they are filled in in the scanning line direction. By doing this for each scanning line from the top of the triangle to the bottom, it is possible to fill the entire interior of the triangle.

(Problems to be Solved by the Invention) However, the resulting triangle displayed has a problem in that jagged edges around the figure are noticeable, as shown in FIG.

This is because in the raster scan method, the display screen is made up of, for example, 512 x 512 pixels in the vertical and horizontal directions, and the presence or absence of a figure is determined for each display pixel, so the boundaries become step-like.

The present invention has been made to solve the above problems, and provides a graphic display device with a simple configuration that makes the jagged edges that occur around the displayed graphic inconspicuous in a raster scan type graphic display. The purpose is to

(Means for Solving the Problems) A graphic display device according to the present invention is a graphic display device that displays graphics using a number of pixels A, and generates a graphic output corresponding to a number nA of pixels, which is an integral number n times the number A of pixels. and an intermediate value generating means for generating an output obtained by averaging the graphic output of the interpolating means every n pixels as a graphic display output of the number of pixels A.

(action).

According to the image processing device configured as described above, the interpolation means generates in advance a graphic output corresponding to the number of pixels nA which is an integral number n times the display pixel number A, and this graphic output is generated every n pixels by the intermediate value generation means. By averaging the values to generate a graphic output having an intermediate value, it is possible to obtain a graphic display output with a pixel count in which jaggedness is not noticeable around the graphic.

(Example) The present invention will be explained in detail below using the drawings.

FIG. 1 is a block diagram showing an embodiment of a solid state display device according to the present invention. In the modeling section 10, 1
1 is a keyboard for inputting coordinate data and color data necessary for graphic display; 2 is a tablet; 3 is a host computer to which the keyboard 1 and tablet 2 are connected and controls the overall operation of the graphic display device; 4 is a disk which is connected to this host computer 3 and stores a predetermined program to be executed. In the graphics section 20, a signal 5 inputs from the host computer 3 a signal S indicating data such as the coordinates of the start and end points of a line segment and the color of the line segment, and performs predetermined calculations based on these input data. An interpolation mechanism section 6 inputs the color data signal S2 and address signal S3 from the interpolation mechanism section 5 and outputs the color data signal S2 and a signal S3 indicating the address of the memory where this is to be written to the next stage. An intermediate value generation unit outputs the color signal S2a averaged for each number of pixels and its address signal S3a to the next stage, and 7 converts the color signal 32a into pixel data in response to the address signal S3a from the intermediate value generation unit 6. 8 is a D/A converter that converts the digital image signal from the frame memory 7 into an analog video signal, and 9 is this D/A converter 8.
This is a raster scan type CRT that displays graphics using video signals from the computer.

FIG. 2 is a block circuit diagram showing the configuration of the intermediate value generating section 6, where 11 is a multiplexer that inputs a part of the address signal S3 from the interpolation mechanism section 5, and 12 and 13 are controlled by the output of this multiplexer 11. A memory 14.15 stores the color data signal S2 for one line, a register 14.15 holds the color data signal S2 for each pixel of the next line, which is controlled by the output of the multiplexer 11, and 16 the memory 12.13. An adder 17 adds together the output data of the registers 14 and 15, and 18 adds the output data of the adders 16 and 17 to generate a color signal s2a. It is an adder.

The operation of the apparatus configured as described above will be explained below. Here, a case of displaying with 512×512 pixels is shown. In the modeling section 1o, the host computer 3 is configured to
It functions to design shapes by calculating coordinate data and color data to display appropriate shapes on the screen.

The graphics section 20 has a function of visualizing the signals from the modeling section 10. Based on the input data S1 from the host computer 3, the interpolation mechanism unit 5 generates 1024
Generates graphic output assuming 0.024 pixels. Address output S3 is X.

A total of 20 bits of signal (10 bits in each direction of y) (X direction: ADRO-ADR9, V direction: ADR10-
ADR19). FIG. 4 is an explanatory diagram showing a part of a polygon in an example of the above graphic output.

In the intermediate value generation section 6, 1024 from the interpolation mechanism section 5
The graphic data output of x1024 pixels is sent to multiplexer 1.
1 in the following order: memories 12, 13 . Two (virtual) scanning lines are stored in registers 14 and 15.

That is, as shown in the explanatory diagram of FIG. 3, first, one portion of the first scanning line L1 is stored alternately in the memory 12 (pixel O in the diagram) and the memory 13 (pixel 1 in the diagram), and then Lines are stored alternately in registers 14 (pixel 2 in the figure) and 15 (pixel 3 in the figure) one pixel at a time. When register 15 is filled, memory 12.13 and register 14.
The pixel data stored in 15 is output to additions 0116 and 17, and the data of the pixels O to 3 are added. Sieve 1
By cutting off the lower 2 bits of the output data at 8,
Perform the operation of dividing by 4. As a result, a signal is generated as the color data output S2a of the adder 18 by averaging the output for every four pixels, and the signal is specified by the address signal 83a of the frame memory 7 by the WRITE signal at the same timing as the write control signal to the register 15. is written to the location where it will be written. Address signal Ssa sets ADR1 to ADR9 of address signal S3 to x
ADRs 11 to 19 are used for the $ mark and the y coordinate.

FIG. 5 is an explanatory diagram showing relative values of the color data output 82a corresponding to pixel positions.

The number of written data for one frame of the color data output S2a to the frame memory 7 is the output S2 from the interpolation mechanism unit 5.
This is 1/4 of the number of data, which is exactly equal to the actual number of display pixels, 512 x 512. However, since the color data output 32a can take an intermediate value, the brightness gradually changes at the boundaries of the displayed figure. Jagged (aliasing)
The result is a smooth display with no blemishes (anti-aliasing function). FIG. 6 shows a display figure based on the color data output S2a by representing each pixel with a size corresponding to its brightness.
It is an explanatory view showing this situation. FIG. 7 is an explanatory diagram showing this for comparison with the case of a conventional device. When the writing of one scan ta to the frame memory 7 is completed, a CLEAR signal from the interpolation mechanism unit 5 causes the memory 7 to
Clear registers 2.13 and 14.15 and prepare for writing the next scan line.

In the above embodiment, the number of bits of the color data is 8 bits, but it can be set to any number of bits depending on the number of bits of the frame memory.

In addition, in the case of color graphics, R is used as color data.
The above device may be configured for each of the three colors GB.

Further, although the above embodiment is a case in which the number of display pixels is 512×512, it may be any number of display pixels such as 1024×1024 or 2048×2048.

Further, in the above embodiment, the average value for every 2×2-4 pixels is used, but the intermediate value may be averaged for every 4×4-16 pixels or 8×8-64 pixels to make the intermediate value finer. For 512×512 display pixels, 2048×2048 pixels may be assumed in the case of 16 pixels, and 4096×4096 pixels may be assumed in the case of 64 pixels.

(Effects of the Invention) As described above, according to the present invention, it is possible to realize a solid display device with a simple configuration in which jagged edges that occur around displayed figures are made inconspicuous in a raster scan type graphic display. be able to.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the graphic display device according to the present invention, FIG. 2 is a block circuit diagram showing the configuration of the main part at 4A in FIG. FIG. 1 is an explanatory diagram for explaining the operation of the apparatus, and FIGS. 7 to 9 are explanatory diagrams showing conventional graphic display. 5... Interpolation means, 6... Intermediate value generation means, S2...
・Graphic output of interpolation means, S2a...Graphic display output.

Claims (2)

[Claims] (1) In a graphic display device that displays a graphic using a number of pixels A, an interpolation means for generating a graphic output corresponding to a number nA of pixels which is an integral number n times the number of pixels A, and a graphic output of the interpolation means is generated every n pixels. and intermediate value generating means for generating an averaged output as a graphic display output of the number of pixels A. (2) The intermediate value generation means includes a holding means for holding pixel signals output from the interpolation means for each l row, and an addition means for adding lm pixel signals output from the holding means for each m pixels for each row. The graphic display device according to claim 1, characterized in that lm=n.