JPH0420508B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to pattern recognition when recognizing optical characters, and more particularly to an apparatus for registering contour features of a pattern.

(Prior art) Conventionally, to detect the outermost coordinates of a pattern,
Main scanning is started in the vertical direction as shown in Figure 1a, or in the horizontal direction as shown in Figure 1b, and is performed by registering the coordinates of the point where the color first changes from white to black. Ta. Therefore, there is a drawback that main scanning is required a total of four times, once each for the top and bottom and left and right sides.

Furthermore, since the detection of discontinuous points in the outermost coordinates is carried out by determining adjacent outer coordinates and using the obtained difference value, there is a drawback that the operation is extremely complicated.

(Object of the Invention) The object of the present invention is to provide an outline detection means for detecting outlines in the forward and reverse directions of main scanning, and a discontinuity point for detecting discontinuous points of the outline in the forward and reverse directions. By adding continuous point detection means, the above-mentioned drawbacks are removed, and the outermost coordinates from the vertical and horizontal directions can be determined by main scanning twice, once in the horizontal direction and once in the vertical direction. An object of the present invention is to provide a pattern contour feature registration device configured to be able to register discontinuous points of contour coordinates.

(Structure of the Invention) The pattern contour feature registration device according to the present invention is used in an optical character reading device, and is configured to include contour detection means and discontinuous point detection means.

The contour detection means adds 8 bits to a two-dimensional shape surrounding a dot made up of target unit bits, and generates a 9-bit two-dimensional shape determined by these 8 bits and the above-mentioned unit bits. The rectangular pattern was formed so that it was possible to read it out at once, and the outline coordinates were registered, and the outline of the rectangular pattern could be detected by main scanning in the forward and reverse directions. It is something.

The discontinuous point detection means is related to the above-mentioned outline detection means, and registers the discontinuous points of the outline coordinates, and detects the discontinuous points of the outline coordinates of the two-dimensional rectangular pattern by main scanning in the forward and reverse directions. It is designed so that it can be detected.

(Example) Next, the present invention will be described in detail with reference to the drawings.

The pattern contour feature registration device according to the present invention adds 8 bits to 1 bit of the address of a binary pattern developed on the memory by surrounding the corresponding bit, and adds 8 bits at a time to 1 bit of the address of a binary pattern developed on the memory. By performing main scanning at once using a 9-layer memory configured to be readable, the outermost coordinates seen from the forward and reverse directions of main scanning are registered, and
This is a device that registers discontinuous points in outer coordinates. Second
Figure a is an example of a pattern in which main scanning is performed only once in the horizontal direction according to the present invention, and Figure 2 b is an example of a pattern in which main scanning is performed only once in the vertical direction, both of which represent characters formed by the above-mentioned main scanning. It is.

Next, the operation will be explained with reference to the drawings.

FIG. 3 shows a block diagram of an embodiment of the pattern contour feature registration device. In Figure 3, 11
is a first pattern memory; 12 is an additional circuit for adding the 8 bits; 13 is a second pattern memory capable of reading out a total of 9 bits at once, including the 8 bits and the central 1 bit; 14 is a first registration circuit for registering the outer coordinates; 15 is a second registration circuit for registering discontinuous points in the outer coordinates; 16 is for storing the registration results of forward side outer coordinates and discontinuous points. a first registration memory for
Reference numeral 7 denotes a second registration memory for storing the registration results of backward side outer coordinates and discontinuous points, 18 a control circuit for controlling addresses of each memory and generating outer coordinates for registration, and 19 storing read data. This is a multiplexer for multiplexing.

In FIG. 3, the pattern contour feature registration device performs main scanning in the horizontal direction. In FIG. 3, the binarized pattern stored on the first pattern memory 11 is applied to the additional circuit 12. In FIG. For example, FIG. 4 is a diagram showing an example of a binarized pattern, and information surrounding the center is added to the center of the pattern shown in FIG. 4 a, as in the pattern shown in FIG. 4 b. ing. In the second pattern memory 13, the information sent from the additional circuit 12 is developed as a pattern that can be read out in 9 bits at the same time.

FIG. 5 is a diagram showing an example of the contour detection pattern, and FIG. 5a shows the contour detection pattern as seen from the forward direction of main scanning, and FIG. It is a figure which shows an example.

Next, the contents of the second pattern memory 13 are read out according to the horizontal scanning controlled by the control circuit 18, and the first registration circuit 14 reads out the contents of the second pattern memory 13 in the horizontal direction that first matches the pattern shown in FIG. 6a. write the address in the first registration memory 16. Also,
The first registration circuit 14 writes horizontal addresses matching the pattern shown in FIG. 6b into the second registration memory 17. Second registration memory 17
should be written when the input information finally matches the pattern shown in Figure 6b, but by writing the information each time, the content is updated each time, and the last content remains. It's becoming like that. Also,
The registration memory is connected to the first and second registration memories 16,
By dividing into 17, a configuration is obtained in which outer coordinates and discontinuous points in forward and reverse directions can be registered simultaneously.

Next, registration of discontinuous points will be explained.

If the difference between the pattern including the outermost part and the outer part adjacent to this pattern is a positive integer (n: n=5 in this embodiment) or more, it is registered as a discontinuous point in the outline coordinates. In the case of the forward direction as shown in FIG. 6a, the point indicated by the arrow (→) is detected as a discontinuous point by the second registration circuit 15 and registered in the first registration memory 16. FIG. 7 shows details of the second registration circuit 15 shown in FIG. 3.

In FIG. 7, 21 and 22 are first and second shift registers, 23, 24, 28,
29 are the first to fourth gates, 25, 2
6 and 27 are first to third flip-flops, respectively. Signals applied via signal lines 251 to 254 are applied to third and fourth gates 28 and 29.
via the first and second shift registers 21,
Added to 22. The first and second shift registers 21 and 22 detect a 5-bit continuous white space, and the first gate 23 detects the first and second white spaces.
The outputs of the shift registers 21 and 22 are ANDed, and the first flip-flop 25 is set by the output of the first gate 23. Then the second
The first flip-flop 26 is latched only by the first pattern shown in FIG. 6d, and the third flip-flop 27 is latched only by the pattern shown in FIG. 6e.

Next, in FIG. 6a, the pattern shown in FIG. 6b is satisfied by the dot a on the pattern, and the third and fourth gates 28 and 29 are opened.
The column above dot b is shifted into the first shift register 21, and the column below dot b is shifted into the second shift register 22. Subsequently, the contents of the first and second shift registers 21 and 22 are ANDed by the first gate 23,
The discontinuity condition is satisfied. Next, the first flip-flop 25 is set and registered in the first registration memory 16.

The discontinuity in the opposite direction is explained as follows according to FIG. 6f. The gate condition is satisfied by "d" in FIG. 6f, the 5-bit continuous white space is detected by "e", and the third
The latch condition of the flip-flop 27 (Fig. 6b)
) is satisfied. In the reverse direction, if the pattern of FIG. 6d is satisfied in "g" or subsequent scans, the discontinuity point is reset.

In the vertical direction, use the same method to find the outermost coordinates,
It is also possible to register discontinuous points of adjacent outermost coordinates.

Incidentally, FIG. 8 is a diagram showing all gate conditions, latch conditions, and reset conditions.

(Effects of the Invention) As described above, the present invention includes a contour detection means for detecting contours in the forward and reverse directions of main scanning, and detecting discontinuous points of contours in the forward and reverse directions. By adding a discontinuity detection means to detect the pattern, all the outermost coordinates of the pattern in the above four directions can be obtained by performing two main scans.
This has the advantage that the presence or absence of a discontinuous point in the outermost coordinates can be registered at the same time during the above scanning.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of main scanning for detecting pattern outer coordinates using a conventional method. Fig. 2 is a diagram showing a character formed by main scanning according to the present invention, Fig. 2a is an example of a pattern in which main scanning is performed only once in the horizontal direction, and Fig. 2b is an example of a pattern in which main scanning is performed only once in the vertical direction. This is an example of a pattern. FIG. 3 is a block diagram showing an embodiment of a pattern contour feature registration device according to the present invention. 4 is a diagram showing an example of the contents of the pattern memory, FIG. 4a is an example of the contents of the first pattern memory in FIG. 3, and FIG. 4b is an example of the contents of the second pattern memory in FIG. 3. It is a figure which shows an example. FIG. 5 is a diagram showing an example of the contour detection pattern, in which FIG. 5a is the contour detection pattern viewed from the forward direction of main scanning, and FIG. 5b
FIG. 2 is a diagram showing an example of an outline detection pattern viewed from the opposite direction of main scanning. FIG. 6 is a diagram showing an example of a pattern showing the detection of a discontinuous point; FIG. 6a is an example showing the detection of a discontinuous point during horizontal scanning in the forward direction;
Figures 6b to 6e show examples of patterns that serve as gate conditions, latch conditions, or reset conditions for detecting discontinuous points, respectively, and Figure 6f shows detection of discontinuous points during horizontal scanning in the opposite direction. This is an example. FIG. 7 is a block diagram of an embodiment showing the detailed configuration of the second registration circuit shown in FIG. 3. FIG. 8 is a diagram showing all gate conditions, latch conditions, and reset conditions. 11, 13... Pattern memory, 12... Additional circuit, 14, 15... Registration circuit, 16, 17...
Registration memory, 18... Control circuit, 19... Multiplexer, 21, 22... Shift register, 2
3, 24, 28, 29...gate, 25, 26,
27...Flip-flop, 121-130,2
51-254...Signal line.

Claims (1)

[Claims] 1. An 8-bit addition circuit that is used in an optical character reading device and adds 8 bits in a two-dimensional manner surrounding the periphery of a dot consisting of a target unit bit;
A pattern outline feature comprising a pattern memory for forming and storing the two-dimensional rectangular pattern of 9 bits determined by the 8 bits and the unit bit so that it can be read out at once. In the registration device, a first registration circuit detects the outer coordinates of the rectangular pattern to be obtained by main scanning the output of the pattern memory in the forward and reverse directions; and a second registration circuit for detecting discontinuous points of the outer coordinates of the rectangular pattern to be obtained by main scanning in the reverse direction, and a forward direction side by the outputs of the first registration circuit and the second registration circuit. a first registration memory that stores the registration results of the outer coordinates and the discontinuous points, and stores the outer coordinates and the registration results of the discontinuous points in the opposite direction by the outputs of the first registration circuit and the second registration circuit; and means for amplifying the data read from the first registration memory and the second registration memory and outputting it as one information signal. Feature registration device.