JPS61256487A - Discontinuous circular arc encoder - Google Patents

Abstract

PURPOSE:To carry out a high speed discontinuous circular arc encoding by extracting candidates of constituting elements and grasping the constituting elements macroscopically and clustering only a reference point of the constituting elements only by a parameter of the distance from a center candidate. CONSTITUTION:The respective segments are recognized by a segment element recognizing section 4, a discontinuous straight line is extracted in a center candidate extracting section 5, 0 is extracted as a center candidate of a circler arc or a circle and a candidate of a constituting element is extracted by a constituting element candidate extracting section 6. At a distance from the center candidate 10, a clustering (r1, r2... classification) is carried out, the class (r2) in which the most candidates of the constituting elements are present, and the constituting elements are extracted. The similar operations are repeated thereafter to connect the constituting elements. Finally, from the distribution of the length of the connected constituting elements, broken lines, chain lines or the like are discriminated to recognize the discontinuous circular arc or the circle and to encode. Thus, a high speed encoding of the discontinuous circular arc can be performed with high recognition rate.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is a method for dividing discontinuous arcs or circles in drawn line figures into line types such as broken lines and chain lines, and encoding them at high speed and with a high recognition rate. The present invention relates to a discontinuous arc encoding device that can perform discontinuous arc encoding.

Conventional technology Conventionally, discontinuous straight lines are recognized as discontinuous straight lines by sequentially connecting component candidates using the direction of component candidates and the distance between component candidates. (e.g., 1981 National Institute of Electronics and Communication Engineers General Conference P5-280), the continuous line arc or circle encoding method involves polar coordinate transformation of the point sequence, and three-dimensional parameters using Rough transformation. Perform clustering and create arcs.

Methods for recognizing circles, etc. (for example, pattern recognition, y (Pattern Recognition)
vol 13゜&2. PP112-122.1981
)) etc. Problems to be Solved by the Invention However, the prior art does not have a method for recognizing and encoding discontinuous arcs or circles.

In view of the above-mentioned problems, the present invention provides a discontinuous arc encoding device that is resistant to noise and capable of high-speed encoding despite being affected by digitization.

Means for Solving the Problems In order to solve the above-mentioned problems, the discontinuous arc encoding device of the present invention extracts discontinuous arcs or circles from an input line figure with a line segment having one open end within a predetermined length. , select one or more points on each component candidate as points representing the position of each component (hereinafter referred to as component reference points), and calculate the sign of the discontinuous straight line. The intersection of the center lines found by recognizes discontinuous arcs or circles. Furthermore, line types such as broken lines and chain lines are recognized from the length distribution of the constituent elements and encoded.

Effect of the Invention The present invention enables high-speed encoding of discontinuous arcs or circles with a high recognition rate using the above-described apparatus.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to the drawings.

FIG. 1 shows the configuration of a discontinuous arc encoding device according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes the discontinuous arc encoding device of this embodiment, in which an input processing section 2 receives data from a line figure input device 3, and a line segment element recognition section 4 inputs line segment elements of the input drawing. The center candidate extraction unit 6 extracts candidates for the center of the arc or circle, the component candidate extraction unit 6 extracts candidates for discontinuous arcs or circle components, and the clustering processing unit T Component candidates are clustered based on the distance from the center candidate to extract components, and a discontinuous arc recognition unit 8 sequentially connects the components to recognize discontinuous arcs and circles. 9, the data is encoded and stored. The encoded data is sent to the display device 1 via the recognition result output section 1o.
1 is output.

The operation of the discontinuous arc encoding device configured as described above will be described below with reference to the drawings.

First, FIG. 2 shows an input line figure, each line segment is recognized by the line segment element recognition unit 4, and the center candidate extraction unit 6 extracts a discontinuous straight line 1++Q2, which is extracted as an OL-center candidate for an arc or circle. Then, the component candidate extraction unit 6 extracts line segments other than the component candidate CfttpQz. FIG. 3 shows the processing in the clustering processing section. Clustering based on distance from center candidate O (here, “I e r2...
...classification of r5), selects the class with the largest number of existing component candidates (r2 in this case), and extracts the component.

FIG. 4 shows the processing in the discontinuous arc recognition unit 8 when both end points of a component are taken as component reference points.

First, focusing on the component a, the component reference point a of the component a. Find the other component reference point b8t closest to the component reference point b8t, connect it to the component candidate, and then find the component cf closest to the other component reference point be of the component reference point S.
: Find and connect.

Repeat the same operation to connect the components, and finally draw a dashed line from the length distribution of the connected components.

Discontinuous arcs or circles are distinguished by dashed lines, etc. (here,
(dashed circle) and encode it.

Although the present embodiment has been described using broken line circles, similar processing can be used to recognize and encode discontinuous arcs or circles such as broken lines and chain lines.

In addition, in this embodiment, the center candidate is the discontinuous straight line "
Although we have explained the case where it is found from the intersection of I + It2, the discontinuity can also be found when the center P1 of the discontinuous circle Q7 is the intersection of the discontinuous straight line Q5 and the discontinuous circle 26 as shown in Fig. 6. Continuous straight line Q5. After recognizing the cine-continuous circle Q6t- by the above process using the intersection point P2 of Q4 as a center candidate, recognize the discontinuous circle 17 as a total center candidate at the intersection P1 of the discontinuous circle Q6 and the discontinuous straight line 15, Can be encoded.

Effects of the Invention As described above, the present invention extracts component candidates, views the components macroscopically, and clusters only the component reference points using only the distance parameter from the center candidate. , since discontinuous arcs or circles are recognized, it is possible to realize a high-speed discontinuous arc encoding device with a high recognition rate.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a discontinuous arc encoding device in an embodiment of the present invention, FIG. 2 is a diagram showing processing in the center candidate extraction section and component candidate extraction section, and FIG. 3 is a clustering process. Fig. 4 is a diagram showing the processing in the discontinuous arc recognition section, and Fig. 5 shows the processing when the center candidate is found at the intersection of a discontinuous circle and a discontinuous straight line. 0 1... Discontinuous arc encoding device, 2...
Input processing unit, 3...Line figure input device, 4...
... line segment element recognition section, 6 ... center candidate extraction section, 6 ... constituent element candidate extraction section, 7 ....
Clustering processing unit, 8...Discontinuous arc recognition unit, e...Encoded data storage unit, 1o...
...Recognition result output unit, 11...Display device. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 @ Figure 4 ^

Claims (1)

[Claims] a preprocessing unit that extracts candidates for constituent elements of discontinuous arcs or circles and center candidates for the discontinuous arcs or circles from line segments having at least one open end and having a predetermined length or less from an input line figure; By clustering the element candidates based on the distance from the center candidate of the arc or circle, extracting the constituent elements, and sequentially connecting the neighboring constituent elements,
1. A discontinuous arc encoding device comprising: a recognition unit that recognizes and encodes broken lines, chain lines, etc. as arcs or circles.