JPS5830624B2 - End point detection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an end point detection method, in particular, while scanning a figure to be recognized in the horizontal direction without applying thinning processing, first scan information and (i+k)th The present invention relates to an end point detection method that detects end points while ascertaining the continuity of graphic strokes based on the black-and-white changing coordinate position and the black-and-white changing coordinate position, based on the th scanning information.

Information on endpoints is extremely important in figure recognition devices, especially in recognizing handwritten characters.

Conventionally, when extracting end points, a figure is scanned, for example, in the horizontal direction, and it is detected that there is no black mesh point in the (i-1)th scan and that a black mesh point exists in the first scan. There are two known methods: (2) a method in which a so-called line thinning process is applied to a figure, and then end point detection is performed.

However, in the former case, end points may be undesirably detected due to blemishes on the figure, and in the latter case, the hardware configuration for the thinning process is troublesome and the figure of the figure to be recognized is Depending on the pattern, the result of the above-mentioned thinning tends to be unstable, such as undesirable so-called "whiskers" or branches.

It is an object of the present invention to take the above points into consideration and to use a simple configuration to detect all end points at the time when the entire figure is scanned without line thinning processing.

The end point detection method for this purpose scans the figure to be recognized in one direction, and uses the scanning information to extract features without applying thinning processing to perform figure recognition. A mesh point change point coordinate extraction circuit unit for extracting a black and white change coordinate position where the white mesh point transitions to the black mesh point and a black and white change coordinate position where the black mesh point transitions from the black mesh point to the white mesh point based on scanning information; A stroke width check circuit unit that determines whether the difference between the black and white change coordinate position obtained during scanning and the black and white change coordinate position exceeds a predetermined value; The i-th scanning black and white change coordinate position and the (i+k
)-th scan information and the (i+k)-th scan black-white change coordinate position obtained by applying the same to the i-th scan information. and the (i+k)th scan black-and-white change coordinate position obtained from the (i+k)th scan information to check the continuity of the stroke by detecting the difference. The condition that the stroke width obtained by the width check circuit section exceeds a predetermined value and the condition that the stroke continuity obtained by the stroke continuity check circuit section exist exist together. The present invention is characterized in that the end points of the recognized figure are detected.

This will be explained below with reference to the drawings.

FIG. 1 is an explanatory diagram for explaining an aspect of end point detection according to the present invention, FIG. 2 is an explanatory diagram for explaining an embodiment of the present invention, and FIG. 3 is an explanatory diagram for explaining the operation of the configuration shown in FIG.

In FIG. 1, 1 is a figure to be recognized, 2 is a figure frame, 3 is a scanning line, 4 is an end point obtained during horizontal scanning, 5 is scanning information, 6 is shift information, 7 is mesh correspondence comparison result information, 8
represents the coordinates Chiful, ST represents the black-and-white changing point, END represents the black-white changing point, and KAZU represents the stroke width information.

As shown in the figure, the recognition target figure 1 is scanned by, for example, performing one horizontal scan from left to right, and then sequentially repeating the scanning downward.

When it is assumed that the illustrated scanning information 5 is obtained during the i-th interval scanning, the illustrated shift information 6 is created by shifting the scanning information 5, for example, by one mesh in the right direction.

Then, mesh correspondence comparison result information 7 is extracted by performing exclusive OR logic on the scan information 5 and shift information 6 for each mesh.

In the information 7, the mesh points indicating the logic rlJ are the black-and-white change point ST1 of the first stroke and the black-white change point END of the first stroke when viewed from the left figure frame in order.
1. Second stroke black and white changing point ST2, second stroke black and white changing point END2. It represents...

Then, the distance between the point ST1 and the point END1 (KA
ZU1) and the distance between point ST2 and point END2 (KA
ZU2) represents the stroke width.

The coordinate information of each change point and stroke width information are compiled into a coordinate table 8 as necessary and used for subsequent processing.

The above processing should be (i
+2 )th scanning is performed in response to...

Then, mesh correspondence comparison result information 7(i) obtained corresponding to the i-th scan and mesh correspondence comparison result information γ(i+1) obtained corresponding to the (i+1)th scan
are compared to check the continuity of the stroke.

That is, the coordinate value of the black and white changing point ST1 in information 7(i) is now nl, the coordinate value of black and white changing point END1 in information 7(i) is nl, and the coordinate value of black and white changing point ST1 in information 7 (i+1) is n2. , Information 7 When the coordinate value of the black-and-white change point END1 in (i+1) is n3, check no-n3ku0 (1) n2-nl<0 (2).

When both of the above equations (IX2) are satisfied, it is determined that the strokes are continuous between the i-th scan and the (i+1)-th scan.

In addition, in order to prevent end points from being detected in an undesired manner due to blemishes, stains, etc., the illustrated coordinate values are checked, and if either equation (3) or equation (4) above does not hold, , it is assumed that the above strokes are not continuous.

The continuity of the strokes is checked as described above, and ([) the strokes are continuous across, for example, at least three scanning lines, and (II) the upper or lower part of the continuous strokes is a white mesh or figure. Under the condition that it is opened by a frame, it is detected as an end point.

FIG. 2 shows the configuration of an embodiment of the present invention, and the reference numeral 9 in the figure is a data route changeover switch, and for example, odd-numbered scan data is distributed to the left route, and even-numbered scan data is distributed to the right route. 10 is a black-and-white changing point controller, 11 is a black-and-white changing point controller, 12 is a figure frame instruction controller that instructs when the scanning point reaches figure frame 2', and 13 to 16 are processing circuits, respectively. 1, 17 to 20 are registers, 21 to 24 are difference circuits, 25 is a threshold α indicating circuit, and 26 is a stroke. Continuity counter,
27 represents a comparator, and 28 and 29 each represent an AND circuit.

When a figure to be recognized 1 as shown in Figure 3 is to be scanned, odd-numbered scanning information is distributed to processing circuits 13 and 14 by a changeover switch 9, and even-numbered scanning information is distributed to processing circuits 15 and 16. be distributed to.

For example, the processing circuits 13 to 16 operate as follows.

That is, the scan information DATA for the i@th scan is processed by the processing circuit 1.
3 and 14, and when one scan is completed, exclusive OR logic is applied as explained with reference to FIG. 1, and the points ST1°Sr1, . . .・・・・・・
The coordinate values of the points END1, END2, . . . shown in FIG.・・・・・・・・・
The coordinate values of are sequentially set in the register 18.

Similarly, scan information DAT for the (i+1)th scan
A is input to the processing circuits 15 and 16, and the points ST1, Sr1, . . . of the illustrated information 7 (i+1) in FIG.
The coordinate values of ... are in the register 19, and the point END1
, END2, . . . coordinate values are set in the register 20.

The difference circuit 21 performs the process shown in equation (1) above,
The difference circuit 22 performs the process shown in equation (2) above.

When both equations (1) and (2) are satisfied, the AND circuit 28 is turned on and instructs the difference circuits 23 and 24 to start processing.

The difference circuit 23 performs the process shown in equation (3) above,
The difference circuit 24 performs the process shown in equation (4) above.

When both equations are satisfied, the AND circuit 29 is turned on and the contents of the counter 26 are incremented by one.

A change in the content of the counter 26 from the value "0" to a value "1" means that an end point may have appeared, and the fact that the content of the counter 26 continues to be incremented by 1 for each scanning line indicates that the stroke is continuous. This means that the counter 26 continues to advance, and the fact that the counter 26 stops advancing means that an end point may have appeared.

The output signal OUT of the comparator 27 is sent to the counter 26.
"Step start" and "step stop" as mentioned above from
Correspondingly, it is used for end point detection.

As described above, according to the present invention, it is possible to sequentially detect end points while scanning a figure to be recognized, and also to check the stroke width, the continuous state of strokes, and the like.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram for explaining an aspect of end point detection according to the present invention, FIG. 2 is an explanatory diagram for explaining an embodiment of the present invention, and FIG. 3 is an explanatory diagram for explaining the operation of the configuration shown in FIG. In the figure, 1 is the figure to be recognized, 2 is the figure frame, 3 is the scanning line, and 4 is the figure to be recognized.
is an end point, 5 is scanning information, 6 is shift information, 8 is a coordinate table, 9 is a data route changeover switch, 10 to 1
2 are controllers, 13 to 16 are processing circuits, 17 to 20 are registers, 21 to 24 are difference circuits, 25 is a threshold α indicating circuit, 26 is a stroke continuity counter, and 27 is a comparator. .

Claims (1)

[Claims] 1. In a pattern recognition device that performs figure recognition by scanning a figure to be recognized in one direction and extracting features without applying thinning processing to the scanning information, A mesh point change point coordinate extraction circuit unit that extracts a black and white change coordinate position where the white mesh point transitions to the black mesh point and a black and white change coordinate position where the black mesh point transitions from the black mesh point to the white mesh point based on the scanning information; a stroke width check circuit unit that determines whether the difference between the black-and-white changing coordinate position and the black-white changing coordinate position obtained during scanning exceeds a predetermined value;
The i-th scan black-and-white change coordinate position obtained based on the first scanning information and the (i0k)-th scan black-white change coordinate position obtained based on the (i+k)th scan information. At the same time, the i-th scan black-white change coordinate position obtained by detecting the difference between A stroke continuity check circuit section is provided to check the continuity of the stroke by detecting the difference from the changed coordinate position, and the stroke width check circuit section detects the condition that the stroke width obtained by the stroke width check circuit section exceeds a predetermined value and the above stroke. An end point detection method characterized in that the end point of the recognized figure is detected based on the presence of a condition that the continuity of strokes obtained by a continuity check circuit unit exists. 2 The black-and-white change coordinate position and the black-white change coordinate position are calculated based on the scanning information obtained on the same scanning line and the shift information obtained as a result of shifting the scanning information by one mesh or more, corresponding to each mesh. 2. The end point detection method according to claim 1, wherein the end point detection method is characterized in that the end point detection method is extracted by comparison.