JPS6357829B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a shape identification device, in particular a straight line connecting adjacent points based on a point coordinate value string in which coordinate values of points on arbitrary line segments are inputted in time series. The present invention relates to a shape identification device that examines the inclination angle θi of the line segment, detects a change point in the shape of the line segment, and separates the shape of the line segment.

Conventionally, in identifying the shape of a figure, there are generally two methods: one using global features and the other using local features. For example, in figure recognition where the coordinate values of points on a figure are supplied sequentially, the former method has a direction that effectively represents the entire shape of a line segment, and the line segment is It is difficult to separate and identify the constituent straight sections and curved sections by shape. In addition, in the case of the latter method, since it is a method that uses information between adjacent points, for example, if a straight line section has a local zigzag pattern, it will be extracted as is. There is a drawback that it can be done.

The present invention aims to solve the above-mentioned problems, and uses information between adjacent points to ignore local deformation within a predetermined range, and performs shape recognition for the above-mentioned shape separation. The purpose is to provide equipment. Therefore, the shape identification device of the present invention detects an increase or decrease in the slope angle of a straight line connecting adjacent points based on a sequence of point coordinate values inputted in time series, and connects the straight lines connecting the points. A shape recognition device that separates formed line segments into shapes according to the shape of the line segment, comprising an increase buffer and a decrease buffer to which the above-mentioned inclination angle is set, and an increase flag that instructs to increase or decrease the above-mentioned inclination angle. The inclination angle θi of the straight line connecting the i-th point and the (i+1)-th point is compared with the contents of the increase buffer, and is predetermined to be in the first state of increasing. A second state in which the decrease exceeds a threshold value and a third state in which the decrease occurs below the threshold value are detected, and the inclination angle θi is compared with the contents of the decrease buffer to determine whether the inclination angle θi is decreased. a buffer update unit that detects a fourth state, a fifth state in which the increase exceeds a predetermined threshold, and a sixth state in which the increase is below the threshold; The inclination angle θi is set in the increase buffer and the increase flag is set, the inclination angle θi is set in the increase buffer and the increase flag is reset in the second state, and the increase flag is reset in the third state. The content of the increase buffer and the content of the increase flag are maintained as they are, the inclination angle θi is set for the decrease buffer in the fourth state, and the decrease flag is set, and the decrease buffer is set in the fifth state. The inclination angle θi is set at the same time as the decrease flag is reset, and the contents of the decrease buffer and the decrease flag are maintained as they are in the sixth state, and the contents of the increase flag and the decrease flag are maintained as they are. The present invention is characterized in that a state in which the content of the flag takes the same pattern more than a predetermined number of times is determined, and the line segment is separated in shape by using the change point of the pattern as the change point of the shape of the line segment. There is. This will be explained below with reference to the drawings.

1A and 1B are explanatory views for explaining the concept of shape identification processing according to the present invention, and FIG. 2 shows the configuration of an embodiment of the present invention.

In the case of the present invention, for example, when the coordinate values of points #1, #2, etc. on any desired line segment 1 as shown in FIG. 3. Correctly identify counterclockwise sections 4, . . . to perform shape separation. For this purpose, as will be described in detail with reference to FIG. 2, the "increase buffer", "decrease buffer", "increase flag", and "decrease flag" shown in FIG. 1B are prepared. Then, set each buffer and flag as follows. The case of line segment 1 shown in FIG. 1A will be explained as an example.

(1) Initially, each of the buffers and flags mentioned above are cleared. However, just before reaching point #1 shown in FIG. 1A, the contents of each of the increase buffer and decrease buffer are θα, and each flag is set to logic “1”. .

(2) In this state, the inclination angle θ ₁ of the straight line in the direction from point #1 to point #2 is slightly increased compared to the inclination angle of the straight line leading to point #1. Therefore, since the inclination angle has increased, the inclination angle θ ₁ is set for the increased buffer. Further, the increase flag is set to logic "1" to indicate an increase. On the other hand, the decrease buffer retains the original value θα because the increase is less than the threshold, while the decrease flag cannot be determined because the increase is less than the threshold and the original logic is correct. Keep "1" as is.

(3) Next, when moving from point #2 to point #3, the inclination angle θ ₂ of the straight line connecting points #2 and #3 is compared with the contents of the increasing buffer θ ₁ and the contents of the increasing buffer θα. In this case, since −TH≦θ ₂ −θ ₁ ≦0 (however, TH is a threshold value), the increase flag is considered undeterminable and the original logic “1” is maintained as it is, and the increase buffer is set to the original value θ ₁ remain as is. On the other hand, since a decrease in the inclination angle has been detected, the decrease flag is set to logic "1" to instruct a decrease.
Since the same decrease is detected in the decrease buffer, the above-mentioned inclination angle θ ₂ is set.

(4) Regarding the inclination angle θ ₃ of the straight line connecting point #3 and point #4, 0<θ ₃ −θ ₂ ≦+TH. Therefore, the increase flag is set to logic "1" to indicate an increase, and the increase buffer is set to an angle _.theta.3 . On the other hand, since the increase is less than or equal to the threshold value TH, the decrease flag is determined to be undeterminable and is kept at its original logic "1", and the decrease buffer is kept at its original value θ ₂ .

(5) Similarly, when going from point #5 to point #6, +TH<θ ₅ −θ ₄ . For this reason, the increase flag is set to logic "1" to instruct an increase, and the increase buffer is set to the above value θ ₅ . On the other hand, since the above increase exceeds the threshold TH, the decrease flag is set to logic "0" to indicate that there is no decrease, and the decrease buffer is set to the value θ ₅ .

(6) When going from point #6 to point #7, θ ₆ −θ ₅ <−TH. Therefore, since the decrease exceeds the threshold TH, logic "0" is set in the increase flag to indicate that there is no increase.
And the above value θ ₆ is set to the increasing buffer. On the other hand, the decrease flag is set to logic "1" to instruct a decrease, and the decrease buffer is set to the value _.theta.6 .

Similar processing is performed sequentially below, but the first
Figure B shows this result.

To summarize the operations of the above processes (1), (2)..., when (A) −TH≦θ _i+1 −θi≦0 −(1), (i) the increase flag remains as it was, (ii ) increase buffer remains the same, (iii) decrease flag is logical "1",
(iv) The decreasing buffer is set to θ _i+1 , and (B) when 0<θ _i+1 −θi≦+TH −(2), (i) the increasing flag is logic “1”, and (ii) the increasing buffer is θ _i+1 , (iii) Decrease flag remains unchanged, (iv)
The decreasing buffer is left as it was, and (C) +TH<θ _i+1 −θi −(3), (i) the increasing flag is logic “1”, (ii) the increasing buffer is θ _i+1 , ( iii) Decrease flag is logic "0",
(iv) The decreasing buffer is set to θ _i+1 , (D) When θ _i+1 −θi<−TH −(4), (i) the increasing flag is logic “0”, (ii) the increasing buffer is set to θ _i+1 , (iii) Decrease flag is logic "1",
(iv) The decreasing buffer is assumed to be θ _i+1 .

By doing this, it becomes possible to identify the straight section, the clockwise section, and the counterclockwise section based on the contents of the increase flag and the decrease flag. That is, it is possible to identify the (1, 1) pattern as a straight line section, the (1, 0) pattern as a counterclockwise section, and the (0, 1) pattern as a clockwise section. Of course, if a locally different pattern of less than a predetermined number occurs at a location as shown by arrow A in FIG. be made to do. Furthermore, since this pattern (1, 0) has been clearly determined at a location as indicated by arrow B in the figure, it is corrected so that it is regarded as the end point of a straight line section. Furthermore, the location shown by arrow C in the figure is corrected so that it can be seen as an inflection point when viewed from the previous and subsequent patterns.

Then, as shown in FIG. 1B, continuous sections of the pattern (1, 1), (1, 0), and (0, 1) are defined as one section.

In addition, the operation (A) shown in the above operation summary,
In (B), the reason why the buffer and flag are kept as they were can be considered to be to ignore the presence of a zigzag state as shown in the straight section 2 of FIG. 1.

FIG. 2 shows the configuration of an embodiment of the present invention. Reference numeral 5 in the figure is an angle detection unit that detects the inclination angle θi of a straight line from point #i to point #(i+1). This can be easily determined by θi＝tan ^-1 y _i+1 −yi/x _i+1 −xi, and in practical terms, y _i+1 −yi/x _i+1 −xi is used as θi. You may also have them represent you. 6 indicates an increase buffer, 7 indicates a decrease buffer, 8 indicates an increase flag, and 9 indicates a decrease flag. Further, 10 is a buffer update processing section, which includes comparison circuits 11 and 12 and an AND circuit 1.
3, 14 and OR circuits 15, 16, and the above operation
Buffers 6 and 7 and flags 8 and 9 are set corresponding to (A), (B), (C), and (D).

Reference numeral 17 denotes a state detection section, which includes shift registers 18, 19, in which patterns (1, 0), (1, 1), (0, 1) as shown in FIG. 1B are sequentially set.
20, AND circuits 21, 22, and 23, and minute range pattern extraction sections 24, 25, and 26, and performs corrections such as arrows A, B, and C shown in FIG. 1B. The results of the corrections made in the state detection unit 17 are then transferred to the data processing device CPU (not shown),
Line segment 1 as shown in Figure 1 corresponds to each section 2, 3, 4.
The shape is separated into

Note that the comparison circuits 11 and 12 have inputs a and b.
Based on this, when a-b>0, a logic “1” is emitted, when a-b<-TH, a logic “0” is emitted, and when 0≧a-b≧-TH, an undeterminable “*” is emitted. configured to emit.

Also, the AND circuit 21 detects the pattern (1, 0), the AND circuit 22 detects the pattern (1, 1), and the AND circuit 23 detects the pattern (0, 1), and synchronizes them with the clock. It is set in shift registers 18, 19, and 20. During this time, the pattern extraction units 24, 25, 2
Examine the pattern in which 6 is input, and use Figure 1 B.
Patterns corresponding to locations such as arrows A, B, and C in the figure are extracted. When a predetermined pattern appears, it is corrected based on the output from, for example, a conversion ROM indexed by the contents of the pattern extractors 24 to 26.

As described above, according to the present invention, it is possible to separate a graphic line segment into a plurality of sections while suppressing local fluctuations.

[Brief explanation of drawings]

1A and 1B are explanatory views for explaining the concept of shape identification processing according to the present invention, and FIG. 2 shows the configuration of an embodiment of the present invention. In the figure, 1 is a line segment, 2, 3, and 4 are sections, 5 is an angle detection unit, 6 is an increase buffer, 7 is a decrease buffer, 8 is an increase flag, 9 is a decrease flag, 10 is a buffer update processing unit, 11 and 12 are comparison circuits, respectively;
17 represents a state detection section.

Claims (1)

[Claims] 1 Detect increases and decreases in the inclination angle of straight lines connecting adjacent points based on a sequence of point coordinate values input in time series, and calculate the line segment formed by connecting the straight lines connecting the points. A shape recognition device that performs shape separation according to the shape is provided with an increase buffer and a decrease buffer for setting the above-mentioned inclination angle, an increase flag and a decrease flag for instructing an increase or decrease in the above-mentioned inclination angle, and an i-th The inclination angle θi of the straight line connecting the point and the (i+1)th point is compared with the contents of the increase buffer, and the first state is increasing, and the second state is decreasing beyond a predetermined threshold. and a third state decreasing below the threshold, and the inclination angle θi is compared with the contents of the decreasing buffer to determine the fourth condition decreasing and a predetermined threshold. A buffer updating unit is provided for detecting a fifth state in which the buffer is increasing above the threshold and a sixth state in which the buffer is increasing below the threshold, and the inclination angle θi is set for the buffer increasing in the first state. At the same time, the increase flag is set, and in the second state, the inclination angle θi is set to the increase buffer, and the increase flag is reset, and in the third state, the contents of the increase buffer and the contents of the increase flag are set. In the fourth state, the inclination angle θi is set to the reduction buffer and the reduction flag is set, and in the fifth state, the inclination angle θi is set to the reduction buffer and the inclination angle θi is set to the reduction buffer. The decrease flag is reset, and the contents of the decrease buffer and the decrease flag are maintained as they are in the sixth state, and the contents of the increase flag and the contents of the decrease flag exceed a predetermined number of times. A shape identification device characterized in that the line segment is separated into shapes by determining a state in which the same pattern is taken over the line, and using a change point in the pattern as a change point in the shape of the line segment.