JPH04364593A - Handwritten character segmenting system - Google Patents

Abstract

PURPOSE:To correctly segment a character image area, to improve the correct reading ratio and to do without performing the drop-out color printing by special ink with the mark sheet to be used. CONSTITUTION:In the character segmenting system of a handwritten character recognizing device having a character segmenting processing part 15 to scan optically the mark sheet to print the rectangular character writing frame to designate the writing position of a character and a position information mark which becomes a reference to count the coordinates of the character writing frame and segment the handwritten character pattern for each one character, the position of the character writing frame is counted from the position information mark by a first segmenting processing part 15 and the rectangular pattern area including the image of the character writing frame is obtained. By a second segmenting processing 18, the condition of the picture element is successively investigated from 4 sides of the pattern area to the inside, the position of the 4 sides of the character writing frame is specialized, the image of the character writing frame and the character image area in the frame are separated, and the pattern of the character image area is obtained.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a handwritten character cutting method, and more particularly to a handwritten character cutting method for cutting out a pattern for each character of a written sentence from an image signal of a mark sheet.

0002

[Prior Art] A handwritten character recognition device that reads a mark sheet and recognizes written characters from its image signal.
A cutting process is required to extract the pattern of each written character from the image of the mark sheet. In order to increase the correct reading rate of character recognition, it is necessary to ensure that the entire image of a single character written in the cut out pattern is included, and to shorten the processing time, It is required to minimize the number of pixels.

[0003] For this reason, mark sheets used as input for conventional character recognition devices of this type have been devised to specify the positions where characters are written.

As shown in FIG. 3, a rectangular character writing frame 31 for specifying the writing position of characters is printed on a mark sheet 34, the size and writing position of the characters are limited, and the coordinates of the character writing frame 31 are also specified. It is common practice to print position information marks 32 and 33, which serve as a reference for calculation, on the periphery of the mark sheet 34.

[0005] In the conventional handwritten character extraction method, the character entry frame 31 is printed in a dropout color based on the cut out pattern, and only the image of that frame is erased using the optical reading section, or the character entry frame 31 is cut out and the size is adjusted. They print it larger and make other improvements.

[0006]

[Problems to be Solved by the Invention] However, in such a conventional handwritten cutout method, a copy of a mark sheet printed in dropout color cannot be used as a mark sheet for filling in, and the optical reading/electrical converter is replaced with a facsimile terminal, etc. noise is likely to occur due to variations in sensitivity to dropout colors,
Furthermore, if the character entry frame is printed in a larger size, it becomes difficult to specify the size and position of the actually written characters, resulting in a problem of lowering the correct reading rate.

[0007]

[Means for Solving the Problems] The handwritten character extraction method of the present invention includes printing a rectangular character entry frame that specifies the character entry position and a position information mark that serves as a reference for calculating the coordinates of the character entry frame. An optical reading section that optically scans the mark sheet and converts it into an electrical signal, a quantization section that quantizes the obtained electrical signal to obtain an image signal, and an image memory section that inputs the image signal and stores image information. and a character extraction processing unit that extracts the handwritten character pattern written on the mark sheet from the image signal one character at a time.
In the second cutting process, the position of the character entry frame is calculated from the position information mark to obtain a rectangular pattern area that includes the image of the character entry frame, and in the second cutting process, the position of the character entry frame is calculated from the position information mark. The positions of the four sides of the character entry frame are identified by sequentially examining the state of the pixels from the side to the inside, the image of the character entry frame and the character image area inside the frame are separated, and the pattern of the character image area is determined. It is characterized by obtaining.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings.

FIG. 1 shows a block diagram of an embodiment of the present invention, and FIG. 2 is a front view illustrating the processing of this embodiment.

In this embodiment, as in the conventional method, a mark sheet 34 on which a character entry frame 31 and position information marks 32, 33 as shown in FIG. Dropout color printing is not performed. This mark sheet 34 is optically scanned by the optical reading section 11 and converted into an electrical signal representing the brightness level, and the brightness level is quantized for each pixel in the quantization section 12 to convert the image information into digital data. The image information converted into digital data is stored in the image memory 13 for the next cutting process. The mark sheet recognition processing section 14 extracts the horizontal position information mark 32 and the vertical position information mark 33 from the image of the entire mark sheet, calculates the coordinates of the character cutting frame position, and sends the cutout processing section 15 to cut out one character each. Give coordinates and size information.

At this time, as shown in FIG. 2, a larger cutout is made with margins on the top, bottom, left and right sides so that the image of the character entry frame 31 is completely displayed within the cutout frame 21. For the next cutting process, the pattern is stored in a small capacity in the image memory unit 16, and the state of the pixels is checked line by line from the top to the bottom, and the black pixel is the first one that exceeds a certain value. Obtain the ordinate Y1 of the line. Similar processing is performed upward from the intention, from the left end to the right, and from the right end to the left to obtain the ordinate Y2 and the abscissa X2. These coordinates are shown in image 2 of the character entry frame.
It represents the position of the outer edge of 2.

[0012] Next, the character entry frame recognition processing unit 17 determines a cutting frame 24 to be cut out at the boundary between the character entry frame image 22 and the input character image 23, assuming that the line width of the character entry frame is also constant. . If the value of the line width of the character entry frame plus the margin is m, the coordinates of the cutting frame 24 are Y1+m,
It is determined as Y2-m, X1+m, and X2-m.

[0013] Each coordinate obtained in this way is cut out and processed by the processing unit 1.
8 and the pattern within the cutout frame 24 is given as an input to the character recognition processing section 19. By cutting out like this,
The character entry frame 31 can be accurately drawn, and characters can be accurately cut out.

[0014]

As explained above, the present invention performs the cutting process in two stages, and in addition to the cutting based on the position information mark, it also provides a means for detecting the position of the character entry frame, thereby improving the character image area. can be extracted more accurately, which has the effect of improving the correct reading rate. Additionally, the mark sheets used do not require dropout color printing using special ink.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the invention.

FIG. 2 is a front view illustrating the process of the embodiment of the present invention.

FIG. 3 is a front view showing an example of a mark sheet used in the conventional method and the present invention.

[Explanation of symbols]

11 Optical reading section 12 Quantization section 13 Image memory section 14 Mark sheet recognition processing section 15 Cutting processing section 16 Image memory section 17 Character entry frame recognition processing unit 18 Cutting processing section 19 Character recognition processing section 21 Cutting frame 22 Image of text entry frame 23 Image of written characters 24 Cutting frame 31 Character technique breast frame 32, 33 Location information mark 34 Mark sheet

Claims (1)

[Claims] [Claim 1] A mark sheet on which a rectangular character entry frame specifying a character entry position and a position information mark serving as a reference for calculating the coordinates of the character entry frame are printed is optically scanned and converted into an electrical signal. an optical reading section, a quantization section that quantizes the obtained electrical signal to obtain an image signal, an image memory section that inputs the image signal and stores image information, and a handwritten character written on the mark sheet from the image signal. In a character extraction method of a handwritten character recognition device having a character extraction processing unit that extracts a pattern one character at a time,
In the first cutting process, the position of the character entry frame is calculated from the position information mark to obtain a rectangular pattern area that includes the image of the character entry frame, and in the second cutting process, the pattern area is obtained. The positions of the four sides of the character entry frame are identified by sequentially examining the state of the pixels from the four sides inward, and the image of the character entry frame and the character image area inside the frame are separated, and the image of the character image area is separated from the character image area inside the frame. A handwritten character extraction method characterized by obtaining patterns.