JPS622356B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a character recognition device, and more particularly to a character arrangement direction detection device for detecting the printing direction of printed or typed characters.

A typical example of a device that reads and recognizes printed or typed characters is an automatic postal code reading and sorting machine (hereinafter referred to as a postal machine). Normally, in this type of mail machine, mail pieces with printed or typed postal codes are sent by large users.
Mail is often shipped in bulk, and mail of the same format from these large users can be processed together. Therefore, conventionally, when a postal machine reads a postal item with this type of postal code, the vertical or horizontal orientation of the postal code is set in advance to make it easier to detect the postal code. . However, when processing many types of postal items with various formats in a short time, or when multiple types of postal items are mixed together, manually setting the direction of the postal code is difficult for the postal machine to process. This poses a major problem in terms of capacity and operation.

As a method of detecting the direction, for example, it is possible to store information obtained by optically scanning mail items in a temporary storage device and detect the directionality based on the results, but the detection method is complicated. ,
There are problems such as recognition processing time and storage capacity.
SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a character arrangement detection device that eliminates the drawbacks of the prior art.

In printed or typed type, the vertical dimension (height) is usually larger than the horizontal dimension (width), except for certain symbols. For example, in JIS-C6250, numbers,
JIS-C6252 specifies the size of the OCR-K font for katakana as well as the OCR-B font for alphabetic characters, but it is clearly larger in height.

Based on this fact, in the present invention, when recognizing a postal code printed on a postal item, it is possible to recognize characters in various sizes of print without having to set in advance the direction of the postal code, which is effective information when reading a postal code. Detecting the top and bottom edges of the block, measuring the vertical and horizontal dimensions of the character block, taking the larger dimension as the length of the type, determining the direction of each type,
From this detection result, it is counted whether the type is vertical or horizontal when viewed from one reference direction, and the direction of the type is determined based on the magnitude of this count value, which is used as direction detection.

Hereinafter, the present invention will be explained in detail with reference to the drawings. FIG. 1 is a schematic diagram of the present invention implemented in a mail machine. In FIG. 1, a postal item 1 is conveyed in a horizontally elongated shape and is optically scanned by a flying spot scanner 2.
The reflected light is received by Photo Multilayer 3,
The signal is photoelectrically converted and quantized to a binary level by a quantization circuit 4, and from this quantized character image signal, a direction detection device 5 determines the directionality of the type on the mail. FIG. 2 shows two directions of the postal code 6 and addressee 7 of the mail item 1 shown in FIG. Further, arrow 8 indicates the mail transport direction, and arrow 9 indicates the optical scanning direction. FIG. 3 is a block diagram of the character arrangement detection device 5 shown in FIG. FIG. 4 shows how the character block "9" is detected within the device.

Next, embodiments of the present invention will be described in detail with reference to FIGS. 3 and 4. In FIG. 3, a quantized video signal 10 is input to a pattern shift register 11, and is sequentially shifted by a clock signal 41 output from a clock circuit 40 as the video signal 10 changes. As shown in Figure 4a, this pattern shift register 11 has a configuration in which n shift registers each having m bits vertically are arranged horizontally. column is reentered. 10a In this pattern shift register 11, when a character pattern is shifted, the lower end, upper end, and left end of the character are detected by the lower end detector 12, the upper end detector 13, and the left end detector 14, respectively. Fourth
The principle of detection will be explained with a diagram. In Figures 4a and 4c, the pattern. Part 32,3 in shift register
A logic circuit detects that all horizontal rows of parts 3 and 34 are "0" (white), and a logic circuit detects that even one bit in one horizontal row of part 31 is "1" (black). A logic circuit is included in the lower end detection circuit 12.
In FIG. 4a, in this example, black is detected in the portion 31, and three lines 32, 33, 3 below this line are detected.
Suppose that the bottom end of the character is detected when all 4 are white. After this, the character pattern is further shifted, and in the state shown in FIG.
Suppose that the upper edge of the character is detected when all 7 are white. The logic circuit for this is the upper end detection circuit 13.
It is in. Also, the information in the registers of the rows in the portion 31 is sequentially ORed with the contents of the compression register 38 between the time when the bottom end of the character is detected and the time when the top end is detected.
When stored in the register 38, vertically compressed information of the character pattern is obtained as shown in FIG. 4b.

In this register 38, when the leftmost bit output 38n is "0" (white) and the rightmost bit output 38m is "1" (black), the left end of the character block is detected by the left end detector 14. . From this register 38, the horizontal size of the character is also detected by the horizontal size detector 18 shown in FIG. In Figure 4b,
There is noise other than the character pattern "9",
In the register 38, only continuous black blocks that do not include white bits from the left side are detected by the horizontal size detector 18.
, and make it the horizontal size of the character. This horizontal size is set in the horizontal size register 20.

As mentioned above, when the lower end, upper end, and left end of a character block are detected, the character block detector 15 determines that one character block has been detected, and the character block detection flip-flop 16 determines that one character block has been detected.
is set. The vertical size of the character block is 3rd
Although it is measured by the vertical size detector 17 in the figure, as in the example in Figure 4, noise may be included in addition to the original character pattern, and in this example, the top edge of the noise is also detected as the top edge of the character block. are doing. Therefore, in order to obtain the vertical size of only the original character pattern, the compression register 3 is used as shown in FIG. 4e.
8, create a gate with the effective horizontal size width of the character pattern in the character block gate register 39, and
When the character pattern shown in FIG.
While it does not become "0", the vertical size of the character block is counted as a valid character pattern by the clock signal 41. The vertical size of the character block obtained in this way is the vertical size. Set in register 19. Examples of patterns from which noise has been removed are shown in FIG. 4d for FIG. 4a and FIG. 4f for FIG. 4c.

Next, the comparator 21 compares the vertical size and the horizontal size of the character block, and a signal 22 when the vertical size is larger than the horizontal size, a signal 23 when the vertical size and the horizontal size are equal, and a signal 23 when the horizontal size is the same. A signal 24 is output when the vertical size is larger than the vertical size. When the signal 22 is issued, the character arrangement is assumed to be in the horizontal direction, and a horizontal direction counter 25 is counted, and when the signal 23 is issued, the character arrangement is assumed to be in the vertical direction, and the vertical direction counter 26 is counted. When the optical scanning of a predetermined area on the mail piece is completed, these counters 2
The comparator 27 compares the values of 5 and 26, and if the value of the horizontal counter 25 is larger than the value of the vertical counter 26, it is assumed that the character arrangement direction is horizontal, and the signal 28 is sent to the vertical counter 26. The value of
If the value is greater than the value of the horizontal counter 25, a signal 30 is issued indicating that the character arrangement direction is vertical, and if the values of the counters 25 and 26 are equal, an undeterminable signal 29 is issued. For example, regarding only the postal code 651-13 on mail item 1 in Figure 2, in the case of a, length > width, length > width, length > width, length < width, length > width, length >
In the end, there are 5 characters whose vertical size is larger, and the value of the horizontal counter 25 is 5, and there is 1 character whose horizontal size is larger, and the value of the vertical counter 26 is 5.
The value of is 1, so it can be inferred that this character arrangement is horizontal. Also, in the case of b, vertical <
When horizontal, vertical < horizontal, vertical < horizontal, vertical > horizontal, vertical < horizontal, vertical < horizontal, the value of the horizontal counter 25 is 1, the value of the vertical counter 26 is 5, and this character arrangement is vertical. It can be assumed that there is.

As explained above, according to the present invention, in a character recognition device that optically reads printed or typed type, it is possible to quickly determine the direction of character arrangement using a simple circuit. This has the effect of making it easier for the character recognition device to extract character patterns and increasing the recognition rate.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a part of the configuration of an automatic postal code reading and sorting machine as an embodiment of the present invention.
The figure shows two directions in which characters are arranged on the mail shown in FIG. 1, where a indicates the horizontal direction and b indicates the vertical direction. FIG. 3 is a schematic diagram of the direction detecting device shown in FIG. 1, and FIG. 4 is a diagram showing a pattern detection process within the pattern shift register shown in FIG. 3.

Claims (1)

[Claims] 1. A circuit for detecting the top and bottom ends of a character block, a circuit for measuring the vertical and horizontal dimensions of this character block, and a circuit for comparing the vertical and horizontal sizes and counting the number of larger blocks, respectively. A character arrangement direction detecting device comprising a circuit for comparing the magnitudes of these counted values, and determining the directionality of a character based on the comparison result.