JPS6160187A - Character recognizer - Google Patents

Abstract

PURPOSE:To separate assuredly rows and characters with the simple control despite the shift of a print position, by correcting the center positions of virtual rows at and after the 2nd row according to the difference between the center position of characters on the 1st row and that of a virtual row. CONSTITUTION:A reading pattern having the width L measured from the upper end of a form is stored to a line buffer 40, and a projected image is obtained by a projection means 51 in the row direction of the buffer 40. The center position of a row is detected from the projected image through a row center position detecting means 52. An arithmetic means 53 obtains a difference alphabetween said row center position and the center position of the 1st row of a virtual row center position buffer 54. A correction means 55 corrects the virtual center positions of the 2nd and subsequent rows. If the virtual center position of the n-th row is defined as An, the virtual center position of the n-th row is corrected to (An+alpha) in consideration of the difference alpha. For the 2nd and subsequent lines, both visual point and field of the buffer 40 are decided based on the value of the corrected buffer 54. Then the rows are separated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a character recognition device, and more particularly to a character recognition device that can reliably detect and cut out character lines on a form.

[Technical background of the invention and its problems]

There are various causes for deteriorating the recognition rate of a character recognition device that recognizes characters recorded on a form.

In particular, changes in character shape due to differences in print quality have a particularly important effect on the recognition rate, but misalignment of print positions due to poor printing accuracy or poor cutting accuracy of forms also has a significant impact on the recognition rate. That is, if there is a misalignment in the printing position, errors occur in line cutting and character cutting, making it impossible to obtain a correct character pattern and causing erroneous recognition.

In order to prevent such misrecognition due to misalignment of the print position, there is a conventional method such as the Freef A-Mat method using a sheet buffer that can store the reading pattern of the entire document. There were problems in that the capacity increased and the cutting method was complicated and time consuming. There is also a method of expanding the field of view by increasing the capacity of the line buffer that stores each bamboo, but if the field of view is expanded, the line pitch of the form must also be increased accordingly, which reduces the number of characters that can be recorded on the form. The problem was that it was getting smaller.

[Purpose of the invention]

The present invention has been made in consideration of the above circumstances, and it is an object of the present invention to provide a character recognition device that can reliably cut out lines and cut out characters with simple control even if the printing position shifts.

[Summary of the invention]

In order to achieve the above object, the character recognition device according to the present invention takes a projected image in the row direction of the reading pattern stored in the storage section, detects the center position of the first character line from this projected image, and detects the center position of the first character line from this projected image. Find the difference between the character line center position of the first line and the virtual line center position, correct the virtual center position for the second and subsequent lines based on this difference, and adjust the character line position based on the corrected virtual line center position. It is characterized by cutting out.

[Embodiments of the invention]

The present invention will be explained below based on an illustrated embodiment. In the character recognition device according to this embodiment, as shown in FIG.
The upper image is photoelectrically converted by the photoelectric converter 10, and the photoelectrically converted electrical signal is quantized by the quantizer 20. The quantized reading pattern is subjected to noise removal by the preprocessing section 30 and stored in the line buffer 40 . From the reading pattern stored in the line buffer, the line detection cutting unit 50
A character line pattern is detected and cut out. When the character line pattern is cut out, the character detection and cutting section 60 cuts out the character pattern for each character and sends it to the character recognition section 70. The character recognition unit 70 recognizes the input character pattern.

The character recognition device according to this embodiment is characterized by a line detection and cutting section 50 that detects and cuts out character lines. This line detection cutting section 5
0 is stored in the projection means 51 that takes a projected image in the line direction of the line buffer 40, the line position detection means 52 that detects the center position of a character line, and the detected line center position and virtual center position buffer 54. a calculation means 53 for calculating the difference between the virtual center position and the virtual center position, a correction means 55 for correcting the value of the virtual center position buffer 54, and a line cutting means 5 for cutting out lines.
6.

The method of detecting and cutting out character lines by the line detection and cutting section 50 will be explained in more detail with reference to FIG.

First, a reading pattern having a width L from the top of the form 1 is stored in the line buffer 40. The projection means 51 takes a projected image of the line buffer 40 in the row direction (horizontal direction) to obtain a projected image as shown in FIG. From this projected image, the row center position detection means 52 detects the row center position. The difference α between this row center position and the 6th position in the first row of the virtual center position buffer 54 is determined by the calculation means 53. Next, the correction means 55 corrects the virtual attached center position for the second and subsequent lines. If the virtual row center position 1 of the n-th row is A, the virtual center position 1 of the n-th row is corrected to An+α in consideration of the difference α. For the second and subsequent lines, the viewpoint and field of view of the line buffer 40 are determined based on the corrected values of the virtual center position buffer 54, and the line buffer 40 is used efficiently to perform line extraction.

As described above, according to this embodiment, since the second and subsequent lines are detected based on the detection of the first line, lines can be detected reliably.

In this embodiment, the field of view of the line buffer is changed depending on when reading the first line and when reading the second and subsequent lines, but a line buffer for two lines is prepared, and when reading the first line, two lines The field of view may be widened by using line buffers for one line, and from the second line onwards, line buffers for one line may be used alternately. This makes it possible to improve positional merging and enable high-speed processing.

Further, instead of the line buffer, a sheet buffer that can store the reading pattern of the entire form may be used. Even when a sheet buffer is used, high-speed processing is possible according to the present invention.

Furthermore, multiple line buffers and sheet buffers are used,
You can speed it up even more by performing parallel processing.

Note that the present invention can be similarly applied to detecting and cutting out character patterns. That is, the first character is detected and the virtual character positions of the second and subsequent characters are corrected from that character position. This enables high-speed character extraction.

〔Effect of the invention〕

As described above, according to the present invention, even if the printing position is shifted, line cutting can be performed reliably and at high speed with simple control, and as a result, it is possible to avoid improving the character TM recognition rate.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a character recognition device according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram of the operation of the character recognition device. 10... Photoelectric conversion section, 20... Quantization section, 30...
- Preprocessing unit, 40... line buffer, 50... line detection cutting unit, 60... character detection cutting unit, 70... character recognition unit.

Claims (1)

[Scope of Claims] A reading unit that reads a form in which a plurality of character lines are recorded, a storage unit that stores the reading pattern of the form read by the reading unit, and characters of the reading pattern stored in the storage unit. A line detection and cutting section that detects and cuts out a line, and a line detection and cutting section that detects each character of the character line pattern cut out by this line detection and cutting section.
In the character recognition device, the character recognition device includes a character detection and cutout section that cuts out each character, and a recognition section that recognizes the character pattern cut out by the character detection and cutout section, wherein the line detection and cutout section is configured to store information in the storage section. a projection means for taking a projected image in the row direction of the stored reading pattern; a line center position detection means for detecting the center position of the first character line from the projected image in the row direction by the projection means; and a line center position detection means for detecting the line center position. a calculation means for calculating the difference between the character line center position of the first line detected by the means and a predetermined virtual line center position of the first line;
1. A character recognition device comprising: a correction means for correcting a virtual line center position after the line, and cutting out a character line based on the virtual line center position corrected by the correction means.