JPS6362781B2 - - Google Patents

Description

[Detailed description of the invention]

(1) Technical field of the invention The present invention inputs graphic pattern data drawn on a drawing in an orthogonal coordinate system and extracts two-dimensional image data to be processed. The present invention relates to an automatic graphic distortion correction method that corrects the pattern cutout width in addition to the position correction. (2) Prior Art and Problems In the conventional art, a graphic pattern of a printed board or the like drawn on a paper using an orthogonal coordinate system is optically read and then stored in an image memory as a binary signal. In this case, processing is performed based on the precondition that the image is drawn at a constant, evenly spaced pitch. However, as shown in FIGS. 1a and 1b, errors occur at a certain pitch during processing due to expansion and contraction of the paper surface. Both sides show an input drawing 1 of the same printed board, and include a graphic pattern in which through holes 2 are connected by line segment patterns 3. This expands and contracts depending on the ambient temperature and humidity, causing non-negligible linear distortion. Figure a shows the case when it is expanded, and figure b shows the case when it is contracted.
Input such a figure pattern as it is into the image memory and cut out to a preset cutting width, for example, N ₁ × N ₁ for through hole 2 and N ₂ × N ₂ for the straight part of the linear pattern. When this is done, as shown in the figure, the corresponding pattern becomes larger than the cutout area in FIG. 1A and there is a gap between it and the adjacent area, and in FIG. 1B the corresponding pattern becomes smaller than the cutout area and the adjacent areas overlap. Any of these will cause errors when processed, for example, by labeling and converting it into code information. On the other hand, the applicant of the present invention set a grid address based on four reference points in the drawing and the number of grids between the reference points as a means of correcting such linear distortion of the drawing, and set the grid address based on the number of grids between the four reference points in the drawing. We proposed a method to correct the position of through holes and linear patterns. By this method, it is possible to correct the linear distortion caused by the expansion and contraction of the drawings described above, and it is also possible to correct rotational distortion caused by the arrangement of the drawings at the same time. However, in this case, predetermined values were used for the cutting widths of the orthogonal axes for cutting out the graphic pattern using the corrected lattice points as a reference. This simplifies masks, etc., but for the same reason as explained in Figure 1 a and b,
Although the error amount is significantly reduced by the position correction, an error based on the cutting width still remains. (3) Purpose of the Invention The purpose of the present invention is to input graphic pattern data drawn on a drawing in an orthogonal coordinate system, and when extracting two-dimensional image data to be processed, to correct linear distortion of the drawing. An object of the present invention is to provide an automatic graphic distortion correction method that corrects pattern cutting width in addition to pattern position correction. (4) Structure of the Invention In order to achieve the above object, the automatic figure distortion correction method of the present invention inputs figure pattern data drawn on a drawing in an orthogonal coordinate system and extracts two-dimensional image data to be processed. In order to correct the expansion/contraction linear distortion of the figure, the figure automatic distortion correction method sets grid addresses based on four reference points in the drawing and the number of grids between the reference points and corrects the position of the figure pattern. The width of the unit grid is calculated from the grid address, and this is set as a parameter to correct the cutting width of the graphic pattern. (5) Embodiments of the invention Figures 2 and 3 are diagrams explaining the principle of the present invention.
A description will be given including the position correction of the graphic pattern according to the proposed example related to the present invention. In Figure 2, for each drawing 1 input to the image memory,
Four reference points (X ₁ Y ₁ ), (X ₂ Y ₂ ), (X ₃ Y ₃ ), (X ₄ Y ₄ ) including the graphic pattern consisting of the through hole 2 and the linear pattern 3 connected therebetween. is set by the image memory address. Then, a grid number M×N is set between these reference points, and a symbol, for example, a through hole 2, is drawn on the grid point indicated by this coordinate value, and a line segment pattern 3 is used to connect between them. This allows you to set the correct position because the coordinates do not change even if it expands or contracts. FIG. 3 is an explanatory diagram of a method for determining grid point coordinates. In the figure, reference points (X ₁ Y ₁ ), (X ₂ Y ₂ ),
(X ₃ Y ₃ ), (X ₄ Y ₄ ) and the number of lattices on the X and Y axes are M,
If N, first the coordinates of the upper side and the lower side of the area are set as coordinate tables 6 and 7. The coordinate tables 6 and 7 are as shown in Tables 1 and 2 below, and are expressed by general expressions (1) and (2).

【table】

【table】

Coordinates of any grid point within the area using equations (1) and (2)
When determining X _kl Y _kl , it can be expressed by equation (3). The above describes the principle of position correction when the drawing is expanded or contracted in the proposed example. In the present invention, the unit cutting width of the lattice of each orthogonal axis is determined using equation (3), and this is used to set the cutting area 8 of the graphic pattern. In other words, if the unit cutting width of the grid is XWD and YWD, then the addresses of the first and second grid point coordinates on the X and Y axes (X ₁₁ Y ₁₁ ), (X ₂₁ Y ₂₁ ) and can be obtained from XWD=X ₂₁ −X ₁₁ YWD=Y ₂₁ −Y ₁₁ (4). The unit cutting width of the lattice obtained from equations (3) and (4) in this manner is set as a parameter in the graphic pattern processing circuit and used for cutting. This makes it possible to eliminate errors based on the cutting width. FIG. 4 is an explanatory diagram of the configuration of an embodiment of the present invention.
In the same figure, a graphic pattern is converted into a binary signal from the drawing shown in FIG. 2 by an optical reading device (not shown) through an image data bus 10, and is stored in an image memory 11 under the control of a control unit (CPU). be done. In this image memory 11, image data N _X and N _Y of the grid number N given by equation (3) are sent to the symbol recognition circuit 13 and the video compression circuit 14 for the drawing pattern of the area within the four reference points described above. The signal is supplied to a graphic pattern processing section comprising a mesh conversion circuit 15. On the other hand, the corrected pattern cutting width given by the above-mentioned equation (4) is stored in the parameter determining circuit 12 and sent to three circuits 13 to 15 of the graphic pattern processing section in correspondence with the grid. For through-holes, the symbol recognition circuit 13 selects grid numbers _N
Using the image data of the pattern cutting width N _XWD and N _YWD corrected with the image data of N _Y1 as the initial value,
Recognize through holes. For the next line segment pattern between through holes, the video compression circuit 14 uses the image data of grid numbers N _X2 and N _Y2 as initial values.
Using _the corrected pattern cutting widths _N Furthermore, the mesh conversion circuit 15 calculates the grid number.
Using the image data of N _X3 and N _Y3 as initial values, and using the corrected pattern cutting widths N _XWD ″ and N _YWD ″, directionality is extracted from the features in the mesh area.
The data from these three circuits 13, 14, and 15 are input into a code information converting circuit 16, where these data are integrated, converted into code information labeled in eight directions, and output as 16-bit concatenated information. Details of the circuits 13 to 16 of the above-mentioned graphic pattern processing section can be found in the patent application filed in 1973 by the applicant of the present invention.
Details are disclosed in No. 155216 "Graphic Conversion Processing Method". In the case of this proposed example, the grid width is set constant, so an error based on this grid width occurs, whereas in the present invention, the parameter determination circuit uses parameters whose grid width is changed according to the expansion and contraction of the drawing. By giving more, the error can be further reduced. (6) Effects of the Invention As explained above, according to the present invention, in addition to correcting the position of the graphic pattern according to the existing proposal, the expansion/contraction linear distortion of each input drawing is corrected by using the position correction data. By correcting the cutting width, errors can be significantly reduced and accurate drawing pattern processing becomes possible.

[Brief explanation of drawings]

Figures 1a and b are explanatory diagrams of the conventional example, Figures 2 and 3
The figure is a diagram explaining the principle of the present invention, and Figure 4 is a diagram explaining the configuration of an embodiment of the present invention. In the figure, 1 is a drawing, 2 is a through hole, 3 is a linear pattern, 6 and 7 are coordinate tables, and 8 10 is an image data bus, 11 is an image memory, 12 is a parameter determination circuit, 13 is a symbol recognition circuit, 14 is a video compression circuit, 15 is a mesh conversion circuit, and 16 is a code information conversion circuit.

Claims (1)

[Claims] 1 When inputting figure pattern data drawn on a drawing in the orthogonal coordinate system and extracting two-dimensional image data to be processed, in order to correct the expansion/contraction linear distortion of the drawing, four reference points in the drawing and the In the figure automatic distortion correction method of setting a grid address based on the number of grids and correcting the position of the figure pattern, further calculating the unit grid width of each orthogonal axis from the grid address,
A figure automatic distortion correction method characterized in that the cutting width of the figure pattern is corrected by setting this as a parameter.