JP2690483B2 - Character line extraction method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an optical character reader (OCR) for reading a character line having no limitation on the description format, and more particularly, to an address directly on a mail piece. The present invention relates to a method for cutting out a character line of an address reading / sorting device for reading and sorting. [Prior Art] Conventionally, in this type of OCR, when cutting out a character line, it is assumed that the character lines do not intersect. Lines were used, and the direction in which they were connected was the direction of character lines. [Problems to be Solved by the Invention] There are many examples of address formats of mails in which character lines intersect as shown in FIGS. 2 (a) and 2 (b). If vertical lines and horizontal lines are not separated from the intersecting character lines in this way, post-processing character cutting and character recognition cannot be performed correctly. Therefore, when the character line of the address / address shown in FIG. 2 is cut out by the conventional technique, the character line is cut out as two vertical lines as shown in FIG. 3 and the horizontal line cannot be read. Against
It is difficult to perform subsequent recognition processing. [Means for Solving Problems] In order to solve the above problems, the character line cutting method of the present invention is based on an image of a paper sheet scanned and input,
First, the character pattern on the paper sheet is divided into a plurality of rectangular blocks including a predetermined character string, and the width of each rectangular block is detected.
And a second step of comparing the widths of the detected rectangular blocks with each other, and as a result of the comparison, the difference between the widths of the other rectangular blocks is larger than a preset value. A third step of detecting a rectangular block as a specific block, and projecting the image in the width of a character included in the specific block and in the width direction of the character based on an image obtained by rescanning the specific block. A fourth step of detecting the distribution density of the characters in the specific block obtained as described above, and other of the character strings included in the specific block based on the width and the distribution density detected in the fourth step. And a sixth step of separating the intersecting character string from other character strings. In this way, by detecting the intersecting character line and cutting and reading it separately from the original character line, the character line can be accurately read and correct recognition processing can be performed. Embodiment Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a flow chart of an embodiment of the character line cutting method of the present invention. First, the same character line cutting as in the conventional case is performed (step 1), and the character width of each character line is detected (step 2). The widths of the detected character lines are compared with each other to check whether the width is abnormally large (step 3). If the width is not abnormally large, the character line is regarded as a vertical line and the process proceeds to the character line image processing. If there is a line with an abnormally large character line width, rescanning is performed for the character line to detect character width and density features (step 4). As a result of the rescanning, it is judged whether or not the character width is significantly larger than other character lines and the minimum value of the density is larger than the others in the character line (step 5), and the character width is increased. If the minimum value of the density is larger than the others, that portion is cut out as an intersecting character line (step 6), and the process proceeds to image processing of the character line. FIG. 4 is a diagram showing the scanning result, the character width, and the density of the mail address shown in FIG. 2 (a). The horizontal character string "1-22-1" is significantly wider than other characters, and the minimum value of the density is larger than other character parts. Therefore, it is determined to be a crossing line in the processing of steps 3 to 5, and Using the space before and after the character as the cutout position, cutting is performed separately from the original vertical character line by the blocking method. [Effects of the Invention] As described above, the present invention detects a crossing character line and cuts it out separately from the original character line, thereby accurately reading the character line having the crossing line and performing correct recognition. There is an effect that can be processed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow chart showing an embodiment of a character line cutting method according to the present invention, and FIGS. 2 (a) and 2 (b) are postal items described in addresses where character lines intersect. Figure showing an example, Figure 3 (a),
(B) is a diagram obtained by cutting out character lines according to the prior art to FIG. 2, and FIGS. 4 (a), (b) and (c) are respectively the second
It is a figure which shows the scanning result of the mail item shown in FIG. 1-6 ... Step.

Claims (1)

(57) [Claims] The first step of dividing the character pattern on the paper sheet into a plurality of rectangular blocks including a predetermined character string based on the scanned image of the paper sheet and detecting the width of each rectangular block; And a second step of comparing the widths of the rectangular blocks with each other, and as a result of the comparison, a rectangular block having a width larger than a preset value by a difference from the widths of other rectangular blocks is set as a specific block. A third step of detecting, and within a specific block obtained by projecting the image in the width direction of the character included in the specific block and the width direction of the character based on the image obtained by rescanning the specific block A fourth step of detecting the distribution density of the characters, and a character string included in the specific block based on the width and the distribution density detected in the fourth step. A character line cutout method comprising: a fifth step of detecting an intersecting character string that intersects another character string; and a sixth step of separating the intersecting character string from another character string.