JPS6229835B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Technical Field of the Invention The present invention relates to a line width determining circuit for an image input device or an image reading device used in an automatic design system or the like.

(B) Technical background Automatic design systems have been used for the design of printed wiring patterns from an early stage, but the proportion of printed wiring pattern design in the design of computers and other devices has recently been increasing.
Therefore, much importance is placed on shortening the design time and reducing the number of design man-hours.

On the other hand, image data processing occupies a very large proportion in the automatic design of printed wiring patterns. Therefore, generally, printed wiring patterns are drawn passing through the intersections of grid lines of equal pitch, and this image data is used at the intersections of the grid lines. The data processing time is shortened by encoding each data and significantly compressing it, thereby reducing the design time and the number of design man-hours.

(C) Prior Art and Problems As mentioned above, printed wiring patterns are generally drawn through intersections b of grid lines a, in which all pitches c are equal and orthogonal to each other, as illustrated in FIG. , such a line image has intersection point b of grid line a
Centered on , the length of one side is c as shown by the dotted line.
For each square divided image, set the line width to large or
One of the three types, medium and small, was determined and coded as shown schematically in Figure 2.

Line width determination circuits conventionally used for such applications target specific grid line pitches, and therefore cannot be used for other printed wiring patterns. Ta.

(D) Object of the Invention The object of the present invention is to eliminate the drawbacks of the conventional example and to provide a line width determining circuit that can be used for printed wiring patterns with arbitrary grid line pitches.

(E) Structure of the Invention In other words, the line width determining circuit according to the present invention raster-scans a divided image obtained by cutting out a line image drawn through the intersections of equally pitched grid lines at each intersection, and calculates the divided image for each pixel. By reading it as binary data and comparing the number of consecutive pixels corresponding to a line drawing part in a predetermined area in the scanning direction with a predetermined threshold value, the maximum line width for each scan is determined by one of multiple types determined by the threshold value. scanning of the divided image by comparing the number of line widths determined for the plurality of types by the first determining circuit within a predetermined area in the sub-scanning direction with a predetermined threshold; a second determining circuit that determines a line width in a direction; and an output of the second determining circuit when the divided image is raster scanned in the horizontal direction, and the divided image is raster scanned in the vertical direction. and an integration circuit that integrates the outputs of the second determination circuit when the line width of the line image is determined for each of the divided images.

(E) Examples of the invention Hereinafter, the gist of the present invention will be specifically explained using examples.

FIG. 3 shows a block diagram of an embodiment of the present invention,
1 is a control circuit that controls each component, and 2 is a line image drawn through intersections b of grid lines a of equal pitch C, as illustrated in FIG. For each divided image obtained by cutting it into squares,
A switching circuit 3 alternately switches the divided image and the output of a video buffer described later and supplies it to a first determining circuit described later; 3 raster scans the divided image supplied from the switching circuit 2 and reads it as binary data for each pixel; a first step of determining the maximum line width for each scan to be one of a plurality of types determined by the threshold value by comparing the number of consecutive pixels corresponding to the line drawing portion within a predetermined area in the scanning direction with a predetermined threshold value; 4 is a first determining circuit 3 within a predetermined area in the sub-scanning direction.
A second determining circuit 5 determines the width of the divided image in the scanning direction by comparing the determined number of line widths of the plurality of types with a predetermined threshold; 2nd time when it was finished
An integration circuit 6 integrates the output of the second decision circuit 4 and the output of the second decision circuit 4 when the divided image is raster scanned in the vertical direction; 6 rotates the divided image at right angles and temporarily stores the resultant output; Video battle, 7
is an area signal generating circuit which generates area signals d and e as shown in FIG. 5 for predetermined areas A and B in the sub-scanning direction Y of the divided image shown in FIG.

FIG. 6 shows a specific configuration example of the first determining circuit 3, in which the divided image f detected by the switching circuit 2 is raster-scanned and the maximum number of consecutive pixels corresponding to the line drawing part in the scanning area is calculated for each scan. The maximum line width for each scan is determined as large, medium, or small by comparing it with two types of threshold values stored in registers 31 and 32, and is output using two bits g and h. be.

FIG. 7 shows a specific example of the configuration of the second determining circuit 4, which uses the area signals d and e to determine the count numbers of the outputs g and h of the first determining circuit 3 for each predetermined area in the sub-scanning direction. By comparing it with the threshold value stored in the register 42, the line width in the scanning direction of the divided image is outputted as 4 bits k, l, m, and n.

Further, FIG. 8 shows a specific example of the configuration of the integrated circuit 5.

With the above configuration, the line width of a line image drawn through the intersections of grid lines of arbitrary equal pitch can be calculated as follows:
Each intersection of the grid lines can be determined to be either large, medium, or small.

(G) Effects of the Invention As explained above, according to the present invention, the line width of a line image drawn through the intersections of arbitrary grid lines of equal pitch can be determined for each intersection of the grid lines. .

[Brief explanation of the drawing]

FIG. 1 is an example of a line image, FIG. 2 is an explanatory diagram of line width determination, and FIG. 3 is a block diagram of an embodiment of the present invention, where 1 is a first determining circuit and 4 is a second determining circuit. ,
5 indicates an integrated circuit. Further, FIGS. 4 and 5 are explanatory diagrams of an embodiment of the present invention, and FIGS. 6, 7, and 8 are diagrams showing the first decision circuit 3, the second decision circuit 4, and the integrated circuit 5, respectively. This is a specific configuration example.

Claims (1)

[Claims] 1. A line image drawn through the intersections of equally pitched grid lines is cut out at each intersection, and the divided images obtained are raster-scanned and read as binary data for each pixel,
a first step of determining the maximum line width for each scan to be one of a plurality of types determined by the threshold value by comparing the number of consecutive pixels corresponding to the line drawing portion within a predetermined area in the scanning direction with a predetermined threshold value; and determining the line width in the scanning direction of the divided image by comparing the number of line widths determined for the plurality of types by the first determining circuit in a predetermined area in the sub-scanning direction with a predetermined threshold value. an output of the second determining circuit when the divided image is raster scanned in the horizontal direction, and an output of the second determining circuit when the divided image is raster scanned in the vertical direction. A line width determination circuit, comprising: an integration circuit that integrates the outputs of the determination circuit, and determines the line width of the line image for each of the divided images.