JPS62138980A - Optical type character reader - Google Patents

Abstract

PURPOSE:To increase the accuracy which can decide a correct character for an unidentifiable character and to improve operability by displaying repectively the unidentifiable read pattern corresponding to various threshold levels of a quantizing part to a display. CONSTITUTION:A photoelectric converting part 11 converts a reading object to an electric signal, stores it to an image line buffer memory 12, a quantizing part 13 quantizes the image signal, a recognizing part 15 executes the character recognition, transfers the character code to a control part 14 and outputs the character code from an output part 21 through an output control part 18. When the character recognition cannot be executed, the first (a) character pattern is displayed through a character correcting control part 17 to a display 20. When the correct character cannot be discriminated, the key of a keyboard 19 is operated, the threshold level of the quantizing part 13 is changed, and the second (b) and third (c) character patterns having the density thicker than the first density are displayed. When the correct character can be decided, the character code is keyed in from the keyboard 19.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to an optical character reading device (hereinafter abbreviated as OCR), and particularly to displaying a reading pattern that is determined to be unrecognizable.

(Prior art) OCR converts reflected light from characters, etc. on a form into electrical signals through photoelectric conversion, and performs character recognition, that is, character recognition, by comparing the resulting image information with pre-stored standard character patterns. It is used for reading.

In such conventional OCR, during the reading process, for example, characters written on a form may not be recognized due to the density of the characters. In this case, characters that cannot be recognized (hereinafter referred to as unrecognized characters)
was displayed on the CRT display in a character pattern with a certain density based on the image information. The operator is
The unrecognized characters were corrected to recognizable characters by referring to the displayed character pattern, and the correct characters were then keyed in from the keyboard.

(Problems to be solved by the invention) However, when correcting unrecognizable characters using OCR having the above configuration, there were the following problems: Unrecognizable characters were generated depending on the density of characters written on a form. In some cases, an operator may not be able to identify the correct character based on only one type of character pattern with a certain density displayed on a CRT display. This is the case, for example, when the unrecognizable characters are characters as shown in FIG. 4(a), and on the other hand, the character pattern displayed on the CRT display is as shown in FIG. 4(b).

Therefore, there is a problem in that the operator has to take out the document that has been read and discharged to the stacker, refer to unrecognizable characters on the document, and key in the correct character. As a result, there were problems in that the OCR continuous processing speed decreased and the operator's operations became complicated.The present invention solves the above problems, increases the continuous OCR processing speed, and improves the operability for the operator. The purpose is to provide excellent OCR.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides the following means in OCR.

The OCR described above includes a storage section that stores optically read read data as a gradation image, and quantizes the gradation image data stored in the storage section based on an adjustable threshold level to create a reading pattern. A quantization unit that outputs, a recognition unit that performs recognition by comparing the reading pattern obtained from the quantization unit with standard patterns stored in a dictionary, and a display that can display reading patterns that are determined to be unrecognizable by the recognition unit. When an unrecognizable reading pattern is displayed on the display unit, the threshold level of the quantization unit is newly set based on a predetermined external input signal, and the unrecognizable reading pattern is displayed on the display unit. and a control section that re-quantizes the corresponding gradation image data and displays the re-quantized reading pattern on the display section.

(Operation) According to the present invention, since the OCR is configured as described above, the operation is as follows.

Characters, figures, etc. on the form are optically read, and this read data is stored as a gradation image in the storage section mentioned above. The quantization section quantizes the stored gradation image at an initially set threshold level, and outputs the quantized reading pattern to the recognition section. The recognition unit recognizes the reading pattern by comparing the reading pattern with marks and patterns stored in the dictionary. The reading pattern determined to be unrecognizable by the recognition unit is displayed on a display unit, for example, a display. Here, for example, if the operator cannot read the displayed reading pattern because it is considered unrecognizable, the control section receives an instruction from the operator, that is, an external input signal. Accordingly, the control section newly sets the threshold level of the quantization section,
The gradation image data corresponding to the reading pattern determined to be unrecognizable is quantized again, and the quantized reading pattern is displayed on the display unit. This character pattern that is determined to be unrecognizable can be repeatedly displayed as a new character pattern on the display section by changing the threshold level of the quantization section according to instructions from the operator (external input signal).

Therefore, since unrecognizable reading patterns quantized by various threshold levels can be displayed on the display section, the above-mentioned problem can be solved.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of essential parts of an OCR according to an embodiment of the present invention. In the same figure, OCR is a photoelectric conversion unit 11
, image line buffer memory 12, quantization section 13, control section 14. Recognition unit 15, dictionary memory 16° character correction control unit 17. It is composed of an output control section 18, a keyboard 19, a display 20, and an output section 21. The photoelectric conversion unit 11 converts reflected light from illuminated characters on a form into an electrical signal. The image line panzer memory 12 is the photoelectric conversion unit 1
The image signal obtained from 1 is stored as a gradation image. The quantization unit 13 quantizes this image signal. The recognition unit 15 compares the quantized image pattern with a standard pattern of characters stored in the dictionary memory 16 in advance to recognize the read character (image pattern). The output unit 21 outputs a character code corresponding to the image pattern recognized by the recognition unit 15. The display 20 displays the image pattern determined to be unrecognizable by the recognition unit 15, and the keyboard 19 is used to correct the image pattern determined to be unrecognizable and key in the correct image pattern.

The control section 14 includes the photoelectric conversion section 11. It controls the image line buffer memo 1J12, the quantization section 13, the recognition section 15, the character correction control section 17, and the output control section 18. Furthermore, the character correction control section 17 controls the keyboard 19 and the display 20.
The output control section 18 controls the output section 21.

FIG. 2 is a diagram for explaining a form read by OCR. As shown in the figure, the form 22 has a line 23 to be read and is conveyed in direction A. A storage area 24 of the line to be read 23 indicates an area stored in the image line buffer memory.

FIG. 3 shows the image line buffer memory 12 shown in FIG.
FIG. In the same figure,
25 is the number of bits that can store all the characters in the direction A and perpendicular to the direction A of the line to be read 23 shown in FIG. 1; 28 is the number of bits that can store the storage area 24 shown in FIG. 1; 27 indicates the number of bits for storing the density of an image pattern (hereinafter referred to as a character pattern) as a gradation image. The zero-order operation will be described.

A line 23 to be read of a form 22 as shown in FIG. 2 is converted into an electrical signal by the photoelectric conversion section 11 and stored in the image line buffer memory 12 as a gradation image. This image signal is quantized by the quantization section 13 and then supplied to the recognition section as a character pattern. Recognition part 15? f. Character recognition is performed by comparing the standard character pattern stored in the dictionary memory 18 with the input character pattern. If the recognition unit 15 is able to recognize the character, it transfers the character code to the control unit 14 as a recognition result. The control section 14 is the output control section 1
The character code is outputted from the output unit 21 via 8. On the other hand, if the recognition unit 15 is unable to recognize the character, the input character pattern is transferred to the control unit 14 as a result of unrecognizability. The control unit 14 causes the display 20 to display the character pattern via the character correction control unit 17.

Here, the relationship between the unrecognizable characters and the character pattern displayed on the display 20 is shown in FIG.
Unrecognizable characters written in the line 23 to be read on the form 22 are shown, and (b), (c), and (d) in the figure each show character patterns displayed on the display 20 corresponding to the unrecognizable characters. .

When an unrecognizable character occurs, a first character pattern as shown in FIG. 4(b) is displayed on the display 20. The density of this character pattern is normally determined by OCR. If the operator is unable to determine the correct character that is a recognizable character by referring to the first character pattern, the operator can select the first character pattern by operating a pre-assigned key on the keyboard 19. A character pattern with a density darker than that of the character pattern is requested. A signal obtained by this key operation (hereinafter referred to as a density conversion signal) is sent to the control section 14 via the character correction control section 17. Then, the control section 14 outputs an image signal corresponding to the unrecognizable character from the image line buffer memory 12 to the quantization section 13, and causes the threshold level of the quantization section 13 to be changed.

As a result, the quantization section 13 supplies the second character pattern having a higher density than the first character pattern to the control section 14 . The control unit 14 includes a character correction control unit 1
7, the second character pattern as shown in FIG. 14(C) is displayed on the display 20.

Here, the operator again judges the characters. If the operator cannot determine the correct character, the keys on the keyboard 19 are operated in the same manner as described above, and a density conversion signal is output to the character correction control section 17. Thereafter, the third character pattern as shown in FIG. 4(d) is displayed on the display 20. Referring to this character pattern, the operator performs character determination again. When the operator is able to determine the correct character from the unrecognized character, he or she keys in the character code from the keyboard 18. The character code is sent to the control unit 1 via the character correction control unit 17.
4. Then, the control unit 14 causes the output unit 21 to output a character code for the unrecognized character in the same manner as for the recognized character.

In addition, if the operator is unable to determine the character even after the third character pattern shown in FIG. By displaying character patterns of various shades the number of times corresponding to the number of bits 27, unrecognizable characters can be corrected.

In Minoru Naoki's style, the first character pattern displayed on the display 20 is gradually displayed with the second and third character patterns of darker density. Instructions can be set arbitrarily. Furthermore, the number of times the density of the character pattern is changed is also arbitrary.

(Effects of the Invention) As described above in detail, according to the present invention, unrecognizable reading patterns corresponding to various threshold levels of the quantization unit can be displayed on the display unit. The effect is as follows.

This increases the probability that an operator can determine the correct character from an unrecognizable character, and reduces the chance of directly referring to unrecognizable characters written on a form. As a result, the continuous processing speed of OCR can be improved, and the operability for the operator can also be improved.

[Brief explanation of drawings]

Fig. 1 is a block diagram of OCR according to an embodiment of the present invention, Fig. 2 is an explanatory diagram of a form, Fig. 3 is an explanatory diagram of a line buffer memory, and Fig. 4 is a character pattern displayed as an unrecognized character. FIG. 11... Photoelectric conversion section, 12... Image line buffer memory, 13... Quantization section, 14... Control section, 15... Recognition section,
16... Dictionary memory, 17... Character correction control unit, 18... Output control unit, 19... Keyboard, 20... Display, 21... Output unit.

Claims (1)

[Claims] A storage unit that stores optically read read data as a gradation image; and a unit that quantizes the gradation image data stored in the storage unit based on an adjustable threshold level and reads the data. A quantization unit that outputs a pattern, a recognition unit that performs recognition by comparing the reading pattern obtained from the quantization unit with standard patterns stored in a dictionary, and a reading pattern that is determined to be unrecognizable by the recognition unit can be displayed. a display section; and when a reading pattern determined to be unrecognizable is displayed on the display section, a threshold level of the quantization section is newly set based on a predetermined external input signal, and the reading pattern determined to be unrecognizable is An optical character reading device comprising: a control unit that requantizes gradation image data corresponding to a pattern and displays the requantized reading pattern on the display unit.