JPS5855981A - Line smoothing system - 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 Conventionally, in the line smoothing method of a raster scan type display, the brightness of a coordinate point obtained from a straight line generator (also called OD A) is determined based on the slope information of the straight line generator (also called OD A); A smooth straight line was created by distributing the luminance to a predetermined level to multiple coordinate points.

In the conventional method, brightness information is obtained from coordinate points indicated by a straight line generator and information such as the slope and direction of travel of the straight line at that point.The brightness distribution within the straight line is continuous; At the connection point between the line and the straight needle, brightness information before and after is not used, resulting in discontinuous brightness, and when displaying free curves made of minute straight lines, the brightness distribution becomes uneven, resulting in jagged curves. .

The present invention provides luminance information obtained from a linear generator by providing at least two or more stages of registers in a pipeline structure.
This is sequentially stored for each step of the linear generator, and the current brightness to be stored in the memory is determined from the brightness information of the previous stage and the brightness information of the next stage. This method allows interpolation of the brightness of the step points occurring between the laskus and the connecting points of straight lines, resulting in a continuous smooth curve.

The present invention will be described in detail below.

The brightness generation information obtained from the straight line generator is the slope information,
There is also step information of the Y counter, information on the short and long axes of the X and μY axes, and the direction of movement of the straight line.

Based on the counter step information of the straight line generator, if smoothing is performed by setting the brightness information to 5 levels and distributing the brightness using two dots per coordinate point, the dots that make up the diagonal line are as shown in Figure 1. The brightness distribution can be generated as shown in . In FIG. 1, the brightness is set to five levels from θ to 4, and the X axis is the long axis. The smoothness increases or decreases depending on the brightness level.

On the other hand, FIG. 2 shows a row of dots in the case of connecting straight lines, where the solid circles are the previously calculated lines, and the broken circles are the dots of the current and next calculations. In this case, various combinations of brightness at the end points of the straight line occur, as shown in the example of FIG. 2 (2a to 2c). This value cannot be predicted from the information of the generator due to the accuracy of the linear generator.

As a result, how to distribute the brightness of the broken line circle is determined by referring to the progress information of the counter at the starting point of the subsequent straight line.

In this method, as the inclination approaches 45 degrees, the accuracy of the step information becomes ambiguous, causing discontinuity in brightness. In the illustrated example, as shown in FIGS. 38 and 3b, even if the end points (@ stages) are in the same combination and the subsequent stages are different, the luminance for interpolation between them is variably distributed.

In FIG. 3c, brightness is determined from post-stage information.

FIG. 4 is a block diagram of a luminance generation method according to the present invention.

The straight line generator includes counters 3 (a) and 3 (b) that generate X-axis and Y-axis coordinate values, and a decimal point calculation circuit 1 that performs addition calculation of slope information to advance the counters.
．． It is composed of a counter step circuit 2 for generating 11111 degree information. The output information of the step circuit 2 is sent to the two-stage pipeline registers 5(a) and 5(b).
Each time the counter increments, it is loaded sequentially and delayed. Therefore, if the respective information of step circuit 2 and registers 5(a) and 5(b) is delayed by one step of step circuit 2 to the X and V coordinate values, register 5(
The output m-information of a) can be the coordinate point brightness of counters 3(a) and 3(b), and past, present, and subsequent brightness information is obtained. By configuring the brightness calculation circuit 4 as a circuit combining information such as the above-mentioned inclination and linear direction, and these three brightnesses, any predetermined value can be set, and brightness between discontinuous points can be interpolated. This allows you to obtain smooth straight lines.

[Brief explanation of drawings]

Figure 1 shows the brightness distribution of the dots that make up the straight line. Figure 2 shows the dot array of the direct connection points. Figure 3 shows the brightness interpolation diagram. Figure 4 shows the block diagram of the brightness generation system. Calculation circuit 2/Counter step information generation circuit 3 (a) X-axis counter (b) Y-axis counter 4, brightness calculation circuit 5 (a) Pipeline register (b) Pipeline register '1gJl-12m 30 ■ #/ 17g 4# Δ μ ffusu #0

Claims (1)

[Claims] In a raster scan type display device, regarding a line smoothing method that displays points with different brightness on multiple rasters and converts a straight step-like waveform into a smooth straight line, coordinate points calculated by a straight line generator, When storing the coordinate point brightness in the memory, it has means for delaying the brightness generation information obtained from the linear generator by at least two stages, and uses the previously stored brightness generation information and the subsequent brightness generation information to be stored next. A line smoothing method that determines coordinate point brightness.