JPH0762860B2 - Character separator - Google Patents

Description

TECHNICAL FIELD The present invention relates to a character separating device used for an optical character reading device or the like for reading a character line whose description format is not limited, and particularly to an address described on a postal matter. In a specific field such as the above, the present invention relates to a character separating device that cuts out individual characters from a character line having no limitation on the description format.

(Prior art and its problems) Conventionally, in a device that optically reads printed characters or handwritten characters (hereinafter referred to as OCR), those that target alphanumeric characters and katakana have already been put into practical use, and recently, handwritten kanji characters. Reading is also being put to practical use. When reading characters using such OCR, character separation technology that cuts out individual characters from the character lines on the paper is essential. In the conventional character separation technology, for example, as shown in IEICE Transactions (D), J68-D, No.8.p1497-1504 (August 1985), character segmentation is performed based on character pitch. Various methods have been developed, including a method for performing and a method for performing character separation by simple white space for alphanumeric characters. When cutting out characters using these conventional character separation techniques, it is assumed that vertical writing and horizontal writing do not coexist in one character line. However,
An example of a case where such an assumption does not hold is a mailing address on a mail item. Addresses on such postal items include handwritten Chinese characters and handwritten numbers. For example, address and address in vertical writing must be written horizontally using abbreviations such as chome and address. There is. In this case, the horizontal part of the address written in abbreviated form (for example, chome and street address) often uses Arabic numerals, unlike the Kanji characters used in prefecture names and names. As described above, when the character lines include partial character lines having different directions, it is necessary to select an appropriate character separation method according to factors such as the direction of the partial character lines. However,
With the conventional character separation technology, individual characters can be cut out accurately and efficiently with respect to character lines that include partial character lines with different directions within the character line, as seen in mail addresses. Was difficult.

The object of the present invention is to solve the above-mentioned conventional problems by detecting partial character lines having different orientations contained in a character line, and detecting the partial character line based on the shape of the detected partial character line or the relative position in the character line. It is an object of the present invention to provide a character separating device capable of efficiently and accurately cutting out a character by changing a method of separating a partial character line into individual characters.

(Means for Solving the Problems) In order to solve the above problems, the means provided by the present invention are: character separation for scanning a plurality of character lines described on a paper surface and extracting individual character images. A device: means for detecting whether or not partial character lines having different directions are mixed in a block character line and dividing the character line into the partial character lines in the same direction; Character separation means is provided, and means for selecting a predetermined character separation means from the plurality of character separation means according to the characteristic of the partial character line and the relative position within the character line.

(Operation) In the present invention, by detecting the presence or absence of partial character lines having different orientations in a character line and changing the character separation method according to the characteristics and relative position of those partial character lines, it is possible to efficiently and accurately It is possible to perform the character cutting process well.

(Example) Hereinafter, the Example of this invention is described, referring drawings.

FIG. 1 is a diagram showing an example of an address on a postal matter in which vertical writing and horizontal writing are mixed, and is for explaining the principle of the present invention.

The hatched characters in the figure represent addresses, and the circles in the figure represent omissions of part of the address. Figure 1 (a)
As shown in the figure, in the character line of, when the projection distribution is obtained in the horizontal direction, a distribution corresponding to a lump of characters or a part of the character (hereinafter referred to as a lump of characters) is generated. The character image can be extracted, but the character images "city" and "4-1-1" in the figure cannot be cut out correctly. Therefore, the horizontal projection distribution is calculated as shown in FIG. 1B for each character block image divided by the horizontal projection distribution shown in FIG. As shown in FIG. 1B, in the character block images “kawa” and “4-1-1”, projection distributions representing three and five partial characters are extracted, and the character block images “kawa” and “4-1” are extracted. Since both horizontal positions of "4-1-1" are known, the position and size of each character block image and the number of elements included in the character block (for example, character block image "Kawa")
And "4-1-1", the number of elements is 3 and 4, respectively. Next, the size of each character block image and the number of elements included in the character block are checked to check the possibility of horizontal writing. For example, in FIG. 1C, the character block images “Kawa” and “4-1-4” are determined to be candidate character block images for horizontal writing from the number of elements and the aspect ratio of the character block images. Then, as the horizontally-written candidate character block image, two regions shown by the symbols L ₁ and L ₃ in FIG. 1C are obtained, and the vertically-written character block image shown by the symbol L ₂ is obtained.

Here, in the present invention, for example, with respect to the horizontal writing characters used in the address on the postal matter, because the chome, address, etc. are often expressed using numbers and special symbols, the horizontal writing candidate character block image of the character line is Since the relative position is also used, as shown in FIG. 1D, the character block image “kawa” is determined to be one character in vertical writing. Regarding character separation here,
The area "4-1-1" which is determined to be horizontally written is separated for each character by a blank space as shown by a dotted line in FIG.
The area determined to be vertically written is separated for each character by the character separating device based on the character pitch, for example.

Although the above processing has been described using the projection distribution, it goes without saying that it can be realized using a method such as contour tracing of a character image. Further, it goes without saying that the present invention can be used without being limited to the vertical address described in FIG.

FIG. 2 is a logic block diagram showing an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a row image storage unit.
A character line image as shown in (a) is stored. A known technique can be used as the technique for detecting the character line image on the paper surface.

2 is a line dividing unit. As shown in FIG. 1B, the line dividing unit 2 divides a character line into partial character lines, and detects the position / size and the number of elements (hereinafter referred to as character block information) of each character block image. Then, it is stored in the character block information storage unit 3. still,
A known technique can be used for the line division unit 2. Based on the position / size and the number of elements of each character block image from the character block information storage unit 3, the partial line determination unit displays a vertical partial line image and a horizontal partial line image as shown in FIG. It is determined whether there is any character block information and the area information of each partial line of vertical writing or horizontal writing is stored in the partial line information storage unit 5.

The character separating unit 6 has a plurality of character separating means built therein, and follows the area information of each partial line stored in the partial line information storage unit 5 and each piece of character block information that are sequentially transferred to the character separating unit 6. Then, a predetermined character separating means is activated, and the character line images stored in the line image storage unit 1 are sequentially cut out for each character and stored in the character image storage unit 7.

(Effect of the invention) As described above, according to the present invention, even in a character line in which vertical writing and horizontal writing are mixed and handwritten characters are also used,
It is possible to easily provide a character separation device that can accurately cut out a character without reducing the processing speed.

[Brief description of drawings]

FIG. 1 is a diagram showing the principle of the present invention using an example of an address on a mail item. FIG. 2 is a logic block diagram showing an embodiment of the present invention. In the figure, 1 is a line image storage unit, 2 is a line dividing unit, 3
Is a character block information storage unit, 4 is a partial line determination unit, 5 is a partial line information storage unit, 6 is a character separation unit, and 7 is a character image storage unit.

Claims (1)

[Claims] 1. A character separating device for scanning a plurality of character lines described on a paper surface to extract individual character images: Whether partial character lines having different directions are mixed in a blocked character line. And a means for dividing the character line for each forward partial character line in the same direction; a plurality of character separating means are provided; And a means for selecting a predetermined character separating means from the individual character separating means.