JPS6330667B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for cutting out characters in an optical character reading device.

Conventionally, when cutting out a character in an optical character reading device, one projection is performed in each of the horizontal and vertical directions, and the character recognition area is defined based on the shadow of the character, that is, the black block, formed as a result. was. However, with this method, if there is noise that overlaps the character (part of an adjacent character, dirt, etc.) during projection, the recognition area is cut out including the noise part, making it difficult to accurately cut out the character. However, the area to be processed in post-processing such as character recognition processing is expanded, and the processing efficiency of the entire device is reduced.

Therefore, the present invention alternately repeats projection in the vertical and horizontal directions on the cutout area, and
By performing the next projection only on the largest block in the projection data from the previous projection, noise around the character to be recognized is excluded, and the recognition area is cut out and constructed along the outer edge of the character. It is an object of the present invention to provide a method for cutting out characters that eliminates the above-mentioned drawbacks.

Hereinafter, the present invention will be specifically explained based on an embodiment shown in the drawings.

As shown in FIG. 1, the optical character reading device 1 has a reading section 2, and a reading data memory 3 and a control section 5 are connected to the reading section 2. The memory 3 is connected to a horizontal projection circuit 7 and a vertical projection circuit 9 that constitute the extraction processing section 6, and the projection circuits 7 and 9 have a horizontal projection register 10,
Vertical projection registers 11 are connected to each other.
A data processing section 12 connected to the projection circuits 7 and 9 is connected to the registers 10 and 11, and a control section 5 is connected to the processing section 12.

Since the optical character reading device 1 has the above-described configuration, the reading section 2 is controlled by a command from the control section 5.
As shown in FIG. 2, the characters 13 that have been read are stored one by one in a cutout area 3a having a width of A bits in the horizontal direction and B bits in the vertical direction in the read data memory 3. (Typically, the character writing paper used in optical character reading devices has a frame formed therein, and characters to be recognized are written in this frame, and the reading section 2 reads the inside of the frame to cut out the cutout area 3a. On the other hand, even if a frame is not formed, when reading a machine-printed form, the size of the paper and the position where it will be printed are known, so the characters are stored one by one. The position can also be predicted to a certain extent. Therefore, the reading unit 2 stores each character in the extraction area 3a by reading this predicted position.)Next, for the total width of the A bit in the horizontal direction of the area 3a, Vertical projection circuit 9 performs vertical projection, and first projection data DAT1 is stored in vertical projection register 11. Data DAT1
Since all the images in the area 3a are projected, some of the adjacent characters recorded together with the character 13 and noise 1 such as dirt in addition to the character 13 in the area 3a are projected.
5, 16, and 17 are also projected in the vertical direction, and their shadow, the black block 19, is as shown in Figure 2a.
Corresponding to noise 15, two digits are formed in x ₁ to x ₂ (one digit corresponds to 1 bit width. The same applies hereinafter), and in correspondence to character 13 and noises 16 and 17, two places are formed in digits x ₃ to x ₄ . Ru. The data processing unit 12 determines from the data DAT 1 that the black block 19 with the maximum width of x ₃ to x ₄ digits is the area on which the character 13 to be recognized is projected.
This time, the width is C in area 3a corresponding to x ₃ to x ₄ digits.
A horizontal projection circuit 7 applies horizontal projection to the entire width of B bits only to the strip area 3b, which is a bit, and stores second projection data DAT2 in the horizontal projection register 10. As shown in FIG. 2c, data DAT2 has noise 15 excluded and y ₁ to y corresponding to noise 16.
y ₂ lines (1 line corresponds to 1 bit width. The same applies hereafter.)
Two black blocks 19 of y ₃ to y ₄ lines corresponding to the characters 13 and noise 17 are formed. Processing section 12
determines that the maximum width black block 19 of lines y ₃ to _{y 4} from data DAT2 is the projected area of the character 13 to be recognized, and this time the width corresponding to lines y ₃ to y ₄ is D bits. The third projection data DAT3 is stored in the register 11 by vertically projecting only the strip-shaped region 3c having a width of C bits and the strip-shaped region 3b having a width of C bits. Then, noises 15 and 16 are excluded, and data DAT3 contains 2 digits x 3 to x ₅ corresponding to character ₁₃ and digits x ₆ to x ₇ corresponding to noise 17, as shown in Figure 2b. x 3 black blocks 19 are formed, and the processing section 12 processes x ₃ black blocks 19 as described above.
The black block 19 of ~x ₅ digits is determined to be the area where the character ₁₃ is projected, and then a strip area 3d with a width of E bits and a strip area 3c with a width of D bits corresponding to x 3 ~ x ₅ digits are formed. The second
As shown in Figure d, the fourth projection data DAT4
is stored in register 10. Then the data
All the noises 15, 16, and 17 are removed from the DAT 4, and only the black blocks 19 of y ₃ to y ₅ lines corresponding to the character 13 are formed. A recognition area 3e where strip areas 3d and 3f with widths E and F bits intersect with each other.
You can know that it exists. In addition,
Recognition area 3e is noise 15, 1 other than character 13
6 and 17 are all excluded and are accurately cut out along the outer edge of the character 13.

As explained above, according to the present invention, character 1
By alternately repeating vertical and horizontal projections on the cutout area 3a where 3 is stored, noises 15, 16, 17, etc. around the character 13 are removed, and the image is projected along the outer edge of the character 13. Since the recognition area 3e is cut out, the correct character 13
It becomes possible to cut out the area, set the area to be processed in post-processing such as recognition processing to an appropriate range, and significantly improve the processing efficiency of the entire apparatus.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of an optical character reading device to which the present invention is applied, and FIG. 2 is an explanatory diagram of cutting out characters from the read data memory of FIG. 1. DESCRIPTION OF SYMBOLS 1... Optical character reading device, 2... Reading unit, 3... Reading data memory, 3a... Cutting area, 3e... Recognition area, 13... Character, 1
5, 16, 17...Noise.

Claims (1)

[Claims] 1. In an optical character reading device that reads characters read from a reading unit and stores them one character at a time in a cutout area of a data memory, projections in the vertical and horizontal directions are alternately repeated on the cutout area, and the previous projection is By performing the next projection only on the largest block in the projection data, noise around the characters to be recognized can be excluded,
A character cutting method characterized by cutting out a recognition area along the outer edge of a character.