JPH0518153B2 - - Google Patents

Description

[Detailed Description of the Invention] [Summary] In an automatic input device that inputs setting data into a computer system, after converting the binary data of the design data into vectors, the relationship between the connections of each vector is extracted, and the connections between the vectors are determined. A means is provided for sequentially subtracting the length of a vector in which one end is an empty terminal or both ends are empty terminals, obtaining a data string of the difference value, and comparing the data string with a specific threshold value. By doing so, the line types of the line segment elements constituting the design data are identified.

[Industrial application field]

The present invention relates to an automatic input device that inputs design data into a computer system, and in particular, inputs the types of line segment elements drawn in design drawings (for example, actual lines, broken lines, one-dot chain lines, two-dot chain lines, etc.) at high speed. The present invention also relates to a line type identification circuit that can reliably identify line types.

With the recent increase in the size of logic devices, the number of logic circuit drawings has increased, and it is now difficult to check whether the logic device operates normally during the logic design stage by making a prototype of the logic device. The trend is that it will become more difficult.

Therefore, it has become necessary to confirm the normality of the logic circuit diagram by, for example, developing the logic circuit diagram on the main memory of a computer system and performing a logic simulation.

At this time, it is necessary to input the logic information described in the logic circuit diagram into the computer system, but in the past, line drawing data was input using a digitizer that required manual labor. Therefore, there are problems with input time and input errors, and automatic input of the logic circuit diagram has become necessary.

Therefore, after reading the logic circuit diagram using photoelectric conversion and storing it in an image memory as binary data, the logic information (line segments, symbols, characters, etc.) is automatically extracted using known pattern recognition technology. By extracting information, it is possible to reduce input man-hours and input errors that occur when manually inputting data using a digitizer.
High reliability of automatic input has become possible.

However, in the conventional method, there is no method for reliably identifying the type of line element, and it is difficult to identify the type of line segment drawn on a design drawing (solid line, broken line, chain line, etc.) at high speed. There is a growing need for effective line type identification circuits that can reliably identify line types.

[Conventional technology]

FIG. 5 is a diagram illustrating a conventional line type identification method, in which a shows an example of a configuration for line type identification, and b shows an example of a histogram created by the conventional method.

First, the vectorization processing unit 2 reads the binarized design data from the image memory 1, and extracts the connection relationship of each vector from the length and slope of each vector.

Specifically, the bending points, cross intersections, and empty terminals of each vector are recognized, and the vectors are recognized as being connected to each other at the bend points and cross intersections.

Furthermore, among the vectors in such a connected relationship, focus is placed on vectors with empty terminals, and a group of vectors whose both ends are empty terminals and whose distances between the empty terminals are within a certain threshold are extracted.

Regarding the vector group extracted in this way,
In the next vector length frequency distribution creation unit 4',
Create a histogram about vector length.

For example, if the histogram shape is unimodal, the connected vector group is recognized as a broken line, and if the histogram shape is bimodal, it is recognized as a dashed line. It is something to recognize.

Figure b is an example of a histogram created in this way, and it can be understood that depending on its shape, it is possible to identify whether the vector is a broken line or a chain line.

[Problem that the invention seeks to solve]

However, conventional line type identification methods extract connected vectors, simply create a longitudinal histogram, and attempt to recognize the line type of the vector based on its shape. Therefore, for example, when different line types are connected, the position of the end point between each line type cannot be accurately recognized and there is a high possibility of erroneous recognition.

FIG. 6 is a diagram illustrating the problems of the above-mentioned conventional method, in which a shows a histogram of a two-dot chain line, and b shows a histogram when the above-mentioned different types of line segments are connected.

As is clear from this figure, even though the histogram of a is a histogram of two-dot chain lines, it shows the same bimodality as the one-dot chain line histogram explained in Figure 6, and the one-dot chain line and the two-dot chain line There was a problem that it was difficult to distinguish between the two.

Furthermore, the histogram b shows a case where different types of vectors, such as a broken line and a dashed-dotted line, are connected, but there was a problem in that the end points of each vector could not be identified even by looking at the histogram.

In view of the above-mentioned drawbacks of the conventional art, the present invention is capable of quickly and easily identifying line types, for example, even when the four types of line types described above and line segments of different types are connected.
The purpose of this invention is to provide a method for accurately extracting the end point positions of each line type.

[Means for solving problems]

FIG. 1 is a diagram illustrating the concept of the present invention, in which A shows an example of a mechanical drawing, B shows the line type identification system of the present invention, and C shows an example of variation of each line type.

The line type identification circuit of the present invention identifies the line types of solid lines, broken lines, one-dot chain lines, and two-dot chain lines drawn on mechanical drawings, architectural drawings, etc.

First, the data handled by the line type identification circuit according to the present invention is the line type obtained by vectorizing the binary image read from the design drawing and taking into account the connection relationship, direction, etc. is an unknown line segment.

In the mechanical drawing shown in FIG. 1A, the line segment whose line type is unknown is L, and the vectors forming the line segment L are v ₁ , v ₂ , v ₃ , . . . _vo , respectively.

Next, by formula (1), calculate the length of each vector in order to obtain the difference value sequence, that is, S _o-1 = | l _o-1 − l _o | ...(1) The invention is characterized in that the line type is identified from the magnitude and change of each value in this difference value sequence.

Now, if you draw a graph of the difference value sequence of each line type, the first
It will look like the figure below.

The line type identification circuit according to the present invention uses a threshold value Te that is set in advance according to the drawing rules for each line type, and if all the difference values are smaller than the above Te, a broken line is displayed as shown in figure a, and if the difference value is larger than the Te. For example, as shown in figure b, a dashed dot line is constructed so that if it is alternately larger or smaller than Te, it can be identified as a chain double dot line as shown in figure c.

However, in the above figure, as shown in equation (1),
Although the illustration is made by taking the absolute value of the difference value, it goes without saying that it is not necessarily necessary to take the absolute value.

In addition, the vectors used to identify the above three types of line types are:
The vector has an empty terminal at both ends, or one end is an empty terminal, and other vectors are not used. Therefore, all unknown line segments remaining after the above three types of line type identification are determined to be solid lines.

The description rules for the various line types obtained using the above method are, for example: - Broken line: The variation in length of each segment is determined by the threshold Te
Within.

Segment _{o-1 o} ｜l _o-1 −l _o ｜＜Te ・Dot-dash line: The length variation of each segment shall be greater than or equal to the threshold value Te.

_{o-1 o} segment Segment ｜l _o-1 −l _o ｜>Te ・ Double-dot chain line: The length and shortness of each segment are the same as the one-dot chain line, and the difference between short segments is the same as the dashed line.

Variations as shown in the diagram illustrating examples of variation of each line type in FIG. 1C are allowed.

[Effect]

That is, according to the present invention, in an automatic input device that inputs design data into a computer system, after vectorizing the binary data of the design data, the relationship of connections between each vector is extracted, and Of each vector, subtract the length of the vector with one end being a free terminal or both ends being free terminals,
By providing means for obtaining a data string of the difference values and comparing the data string with a specific threshold value, the line type of the line segment element constituting the design data can be identified. For example, since four types of lines can be identified quickly and reliably, it can be used to identify line types in various design drawings and can be applied to interpreting the meaning of figures formed by each line type. Further, there is an effect that the drawing rules for each line type can be relaxed.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.
FIG. 2 is a diagram schematically showing an embodiment of the present invention, where → indicates a control line, and indicates a data flow, in which the difference value calculation section 3 and the comparison circuit 5 are These are the functional blocks necessary for implementation. FIG. 3 is a diagram showing a line type identification processing procedure according to the present invention, and FIG. 4 is a diagram showing an example of identification when different line segments are connected.

Hereinafter, an embodiment of the present invention will be described with reference to FIG. 2 and the line type identification processing procedure shown in FIG.

First, the vectorization processing unit 2 extracts the connection relationship of each vector from the length and slope of each vector with respect to the binarized data read out from the image memory 1.

After performing the process of finding line segment data whose line type is unknown among the extracted vectors, the following process begins.

Extract an isolated vector with free terminals at both ends and measure its length.

Extract the vector with a free terminal at one end and measure the length.

Compute sequentially from the end of the unknown line segment to find the difference value.

The magnitude of the difference value is compared with the threshold value Te mentioned above to determine the line type and register it.

The above-mentioned processes are performed on all the unknown line segment data, and when it is detected that the process is completed in the process, the remaining unknown line segments are determined to be solid lines in the process.

When such line type identification processing is performed, for example, even when different line segments are connected as shown in FIG. , the change in the difference value (for example,
The connection point can be recognized by the difference between s ₁ to s ₃ and s ₄ to s ₈ ).

In this way, the present invention extracts individual isolated vectors (vectors with empty terminals) from a group of connected vectors, and detects changes in the lengths of these individual vectors. The feature is that the line type is identified by subtracting the length of each vector sequentially from the end and comparing the data string of the difference value with a specific threshold Te.

[Effects of the Invention] As explained above in detail, the line type identification method of the present invention is such that in an automatic input device that inputs design data into a computer system, after vectorizing the binary data of the design data, By extracting the connection relationship between each vector, subtracting the length of each mutually connected vector in order, obtaining a data string of the difference value, and providing a means to compare the data string with a specific threshold value. Since it is designed to identify the line types of the line segment elements that make up the above design data, it is possible to identify four types of lines quickly and reliably, so it can be used to identify line types in various design drawings. , can be applied to the semantic interpretation of figures formed by each line type. Further, there is an effect that the drawing rules for each line type can be relaxed.

[Brief explanation of drawings]

FIG. 1 is a diagram explaining the concept of the present invention, FIG. 2 is a diagram schematically showing an embodiment of the present invention, FIG. 3 is a diagram showing a line type identification processing procedure according to the present invention, and FIG.
The figure shows an example of identification when different line segments are connected, FIG. 5 is a diagram explaining the conventional line type identification method, and FIG. 6 is a diagram explaining the problems of the conventional method.
It is. In the drawing, 1 is an image memory, 2 is a vectorization processing section, 3 is a difference value calculation section, 4' is a vector length frequency distribution creation section, 5 is a comparison section, v ₁ to v _o are vectors, and l ₁ to l _o represents the vector length, and s ₁ to _{s o-1} represent the difference values of each vector, respectively.

Claims (1)

[Claims] 1. In an automatic input device for inputting design data into a computer system, binary image data stored in an image memory 1 is vectorized, and the vectorization processing results in the following:
A means 2 is provided for extracting a connection relationship between each vector from the length and slope of each vector, and one end of each vector having the connection relationship is provided.
Extract a vector with empty terminals at both ends, measure the length of the extracted vector, subtract the length of each of the vectors in order from the connected end vector, and calculate the difference value data. A means 3 for determining the difference value obtained by the means 3 and a means 5 for comparing the data of the difference value obtained by the means 3 with a specific threshold Te, and based on the comparison result by the means 5, the vector constituting the design data is determined. A line type identification circuit characterized by identifying a line type of (line segment element).