JPS5876977A - Line drawing detecting method - Google Patents

Abstract

PURPOSE:To pick up a line drawing only, by detecting a background area other than a part corresponding to the internal side of a closed drawing from a drawing scanned and sampled in two-dimension lattice shape and taking logic operation between the background area and the sampled drawing. CONSTITUTION:A pattern design drawing 101 of a printed wiring board is scanned in two-dimension lattice shape for quantization sampling. A sampled drawing 201 of the background area eliminating closed drawings 1021-1029 from the drawing 101 is formed. The drawings 101 and 201 are logically processed to pick up line drawings 1031-1036 from other drawings separatingly. Thus, the automatic reading processing only for line drawings can very easily be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for detecting line figures required for automatic reading of drawings.

Drawings, for example, pattern design drawings for printed wiring boards (hereinafter referred to as PWB) In order to create original pattern films, K needs to convert the contents of the drawings into numerical data for creating original images in any small form. However, in the past, this work involved humans inputting all the information using digitizers. For this reason, the required work time was extremely long, and the input of incorrect information was unavoidable due to the monotonous work. In view of these circumstances, a device that automatically reads drawings and converts them into data was developed. However, since the drawing reading work includes relatively advanced figure judgment processing, this type of automatic machine has rarely been provided in the past. This is the reality.

An object of the present invention is to provide an effective method for automatically reading and processing PWB pattern design drawings and the like.

The following description will focus on the PWB pattern design drawing c (hereinafter simply referred to as drawing).

In general, a drawing is composed of a notation part representing a figure, a background part which is the drawing paper itself, and K.

In addition, the notation figures are further composed of various symbols and line figures connecting them. When automatically reading drawings, applications have been filed for closed figure detection devices and detection methods, but these are related to the detection of the positions and types of symbols. be.

In the above invention, we pay attention to the fact that there are many shapes in which the symbols shown in the drawings are closed, such as circles or squares, and examine whether the lines that make up the shapes are closed or not. It was intended to separate various symbols. In other words, if a line constituting a figure is closed, the background part of the drawing is divided into two parts by that line.The outermost edge of the drawing area is the outermost part of the background that the closed figure is divided into. Since it is considered to be a closed background part, if you call to detect a connected background part that cannot be defined even by a line from the outermost edge, the closed background part will be left behind.
The presence and position of closed nine figures such as symbols can be detected.

The present invention relates to the processing of unclosed line figures, that is, lines whose top and bottom or left and right sides are surrounded by a continuous background area that is not obstructed by lines from the outermost edge. By detecting line figures that are closed, it is possible to separate and extract unclosed lines, and it is also possible to easily determine the positional information of the start and end points of the line and other characteristic points. , which provides an extremely effective method for automatically reading drawings.

Generally, drawing information is scanned and sampled in a two-dimensional grid of MAN using a photoelectric converter, and its brightness level is
The value is quantized and stored in the drawing tag. The line figure detection method according to the present invention can be easily realized by executing simple and uniform processing on the drawing information stored in this way.

Hereinafter, the content of the present invention will be explained in detail with reference to the F1 drawing.

Figure 1 is a simulated Kl! It shows a drawing of the Eagle Nine PWB. There are nine symbol figures 1G21.1022.1G23.1024.1 in the drawing whose outermost edge is indicated by a rectangle 101.
0251026.1027.102 & 1029)
, and six line figures 1031.1032.1033
．． 1034.103 There is a closed line figure 104 that forms a steel foil part on the wire 1036 and the PWB ◎ In the line figure detection method according to the present invention, an unclosed line figure 1031.1032.1033.1034 .10
By separating and extracting only 35.1036 from other groups of figures, the subsequent judgment is easy! It makes it easier.

These closed φ line figures constitute conductor lines on the PWB, and are essential information for automatic reading and editing of drawings.

Figure 2 shows the result of Japanese Patent Application No. 5←90245 filed by the same applicant.The background part other than the inside of the closed figure is considered to be the background part 201 connected to the outermost edge of the drawing, and the background part is connected to the outermost edge of the drawing. Stored in the storage unit.

Figure 3 (Xun is a diagram when a part of the drawing information stored in the drawing memory 11 is extracted, and the small rectangle 301 in the figure
．． 302 represents one sampled pixel.

Here, pixel 301 having a value of %θ' is assumed to be the background part, and 1
If we consider the pixel 302 with the value .
A) can be regarded as a part of a line figure that continues in the horizontal direction. Here, the depicted figure is composed of lines with a finite thickness within a certain range, and, excluding errors introduced during quantization, has a certain line width on average, or in other words, a certain number of pixels.

Figure 3 (- is an example in which connection determination processing is performed from the outermost edge of the drawing), Figure 3 (If the line figure in the field is not closed, the connected pixel '''1' 311 and the line figure part, that is, the non- Connected pixel % Therefore, it is easy to extract only the round line figure with the upper and lower ψ sandwiched between the connected areas on the left and right, and it is only necessary to focus on the area where the maximum line width is slightly larger than the symbol. Closed figures corresponding to can be excluded.

Figure 4 is not closed! In an example of implementing the method according to the present invention that does not extract only figures, the drawing storage unit 40λ
The data in the connection storage unit 401 is stored as a sampling grid Mi in the drawing.
A shift register 4041.4G42.4043°4044,4 with a length corresponding to N horizontal pixels WkM
045.4046.4047.4048 KF primary feed 9
When the following conditions are met! ! Graphic storage section 403
In other words, 'l', that is, a line figure is embedded in the area, and in other cases, it is set as 1X', that is, a background part.

Condition C) 11-0 must be X! -〇futsua, -1 and y, -1 and y・-1 The first example in Figure 4 is an example of the configuration of a horizontal line diagram in which the maximum line width of the line figure is 2 pixels. However, vertical line figures and line figures in 45 directions can also be easily constructed by similar means.

FIG. 5 is an example in which the means described in FIG. 1 and FIG.
Only 504.505.506 are separated and extracted.

It should be noted that various information regarding the example wandering line figure shown in FIG. 5, such as the coordinates of the starting point and ending point, can be easily obtained using ordinary techniques, and will not be described here.

As described above, by using the line figure detection method according to the present invention, it is possible to easily extract only unclosed line figures from a drawing in which each Maki symbol figure and line figure are mixed, and as a result - automatic figure reading process is extremely easy to implement.

[Brief explanation of drawings]

Fig. 1 is a simulated PWB drawing created to explain the present invention in an easy-to-understand manner, and Fig. 2 shows line figure detection for Fig. 1. Fig. #I4 is a block diagram showing an embodiment of the detection method using the lid of the present invention, and Fig. FIG. 3 is a diagram showing the results of performing the gland solid detection method using F14 on the Mb1 diagram. In the figure, 101 is a rectangle indicating the outermost edge of the drawing, 104 is ai
W4 line figure showing the pattern, 01 is the connection judgment area, 4
01 is a connection storage unit, 402 is a drawing m & 6. 403 is a striped diagram tag, 4051.4052 is a negative circuit, 406
1 Theory C 3! It is a one-building circuit.

Claims (1)

[Claims] A drawing in which the line figures and various cyndals written on the drawing are scanned and sampled into a two-dimensional grid using a photoelectric transducer, and the brightness levels are quantized into 200 million and stored. Based on the image data, it is determined whether the observation point corresponding to the background part in the rectangular drawing area is connected with the observation point detail at the outermost edge of the rectangular area with the same quantization value. A line figure detection method characterized by detecting a background area other than a portion corresponding to the interior as a connected area, and detecting only line figures sandwiched between the connected areas, that is, line figures that do not constitute a closed figure.