JPH05258105A - Character segmenting device - Google Patents

Abstract

PURPOSE:To precisely segment a character from a blurred character string one by one. CONSTITUTION:A video signal (a) inputted from a camera l is AD-converted 2 and binarized 3. A closed area detection circuit 4 detects a circumscribed rectangle in a closed area more than a previously decided area. A character external form retrieval area generation circuit 5 sets a character external form retrieval range obtained by enlarging it by character interval data for right and left. The circumscribed rectangle including all the closed areas included in the character external retrieval range is set to be a character segmenting range even if it is one picture element.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a character slicing device for slicing a target character in character recognition or the like, and particularly to a process for detecting a character area of each character from a character group consisting of a plurality of characters whose character positions are indefinite. Character cutting device.

[0002]

2. Description of the Related Art In a conventional character cutting device, a closed area of "1" having an area smaller than a specified area is excluded as noise, and an image is cut out using a circumscribed rectangle of a closed area of "1" having a specified area or more as one character area. To do.

FIG. 5 is a diagram for explaining a character cutting method in a conventional character cutting device. In a character in which the character to be cut out is a single character and is divided into a plurality of closed areas due to faintness, the closed area a2 having a specified area or less is excluded as noise, and the circumscribed rectangle 9 of the closed area a1 having a specified area or more is Is the area to be cut out.

[0004]

In the above-described conventional character cutting method, in a character in which a character to be cut out is divided into a plurality of closed areas due to blurring or the like, a closed area having a predetermined area or less is excluded as noise. However, there is a problem that a character cutout area is determined by a closed area having a size equal to or more than a specified area, and an area narrower than an actual character area is cut out.

[0005]

A character cutting device of the present invention includes a camera for picking up an image of a character to be recognized, an AD conversion circuit for AD-converting a video signal input from the camera and outputting a grayscale image signal. The binarization circuit for inputting the grayscale image signal and converting it into a binarized image of "1" for a portion brighter than a predetermined value and "0" for a dark portion is output from the binarizing circuit. A closed area detection circuit for inputting a binarized image signal and calculating the external coordinates of a circumscribed rectangle of a closed area of "1" having an area larger than a predetermined value, and a character interval data storage circuit for storing character interval data. A character contour search area generation circuit for generating a character contour search area laterally expanded by the character spacing data output from the character spacing storage circuit in the outer coordinates of the circumscribed rectangle output from the closed area detection circuit; The above A character outline search circuit for inputting a binarized image signal to calculate the character outline coordinates of all closed regions of "1" included in even one pixel in the character outline search region, and a binary output from the binarization circuit. And an image cutout circuit that cuts out a circumscribed rectangle including all closed areas of "1" searched from the characterized image to the character outline search circuit.

[0006]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. The camera 1 captures an image of a character to be recognized and captures a video signal a
Is output. The AD conversion circuit 2 AD-converts the video signal a input from the camera 1 and outputs a grayscale image signal b. The binarization circuit 3 inputs the grayscale image signal b, converts a lighter part to "1" than a predetermined value and a darker part to "0" and outputs a binarized image signal c. .. The binarization level is determined in advance so that the character portion is "1" and the background portion is "0". The closed area detection circuit 4 receives the binarized image signal c output from the binarization circuit 3, and has a larger area "1" than a predetermined value to eliminate the closed area "1" due to noise. Only the closed region of "" is searched, the external coordinates of the circumscribed rectangle of the searched closed region are calculated, and the external coordinate signal d of the circumscribed rectangle is output.

In the character interval data storage circuit 6, character length data between characters are stored in advance, and a character interval data signal e is output. The character outline search area generation circuit 5 generates a character outline search area expanded to the right and left sides by the character interval data output from the character interval storage circuit 6 at the external coordinates of the circumscribed rectangle output from the closed area detection circuit 4. Then, the character outline search area signal f is output. The character outline search circuit 7 inputs the binarized image signal c, searches for all "1" closed regions that include even one pixel in the character outline search region, and calculates a circumscribed rectangle including all closed regions that have been searched. Then, the character outline coordinate signal g is output. The image cutout circuit 8 receives the character outline coordinate signal g and cuts out an image within the character outline coordinates from the binarized image data output from the binarization circuit.

Next, the operation of this embodiment will be described with reference to FIGS.

FIG. 2 shows a case in which a character to be recognized is binarized, and a circumscribed rectangle (X ₁ , Y ₁ ) of a closed region having a size equal to or larger than a previously cut area is
This is an example of detecting (X ₂ , Y ₂ ). The circumscribed rectangle is generated by excluding the closed region a2 and leaving only the closed region a1.

FIG. 3 shows a character outline search area (X ₃ , Y ₃ ), which is expanded to the right and left by the character interval data output from the character interval storage circuit 6 on the external coordinates of the circumscribed rectangle.
This is an example of generating (X ₄ , Y ₄ ). Assuming that the character spacing data L is stored in the character spacing data storage circuit 6 in advance, the character contour search areas (X ₃ , Y ₃ ) and (X ₄ , Y ₄ )
Is calculated by the equations (1) and (2).

(X ₃ , Y ₃ ) = (X ₁ −L, Y ₁ ) ... Formula (1) (X ₄ , Y ₄ ) = (X ₂ + L, Y ₁ ) ... Formula (2) FIG. All the closed areas of “1” that include even one pixel in the outer shape search area are searched, and circumscribed rectangles (X ₅ , Y ₅ ), (X ₆ , Y ₆ ) including all the searched closed areas are generated. ing. In addition to the closed area a1, the closed area a2 is included in the character outline search area even for one pixel, so that the closed area a1 and the closed area a2 are included.
A circumscribed rectangle containing is generated. Further, since the character outline search area is generated by expanding the circumscribed rectangles (X ₁ , Y ₁ ) and (X ₂ , Y ₂ ) to the left and right by the character interval data L, a closed area a3 of "1" of another adjacent character is generated. Accurate 1 without including
It is possible to generate a circumscribing rectangle of only characters.

[0013]

According to the character cutting device of the present invention, in addition to the closed area having a predetermined area or more, the character circumscribing rectangle obtained from the closed area having a predetermined area or more is widened to the right or left by the character interval data. By setting a character outline search range and searching for all closed regions included in the character outline search range even with one pixel, a closed region with a small area of a faint character is included and adjacent to detect the character cutout range. Since it does not include the closed area of the character, it has the feature that the character can be cut out accurately.

[Brief description of drawings]

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

FIG. 2 is a diagram showing a circumscribed rectangle detected by a closed region detection circuit 4 in FIG.

FIG. 3 is a diagram showing a character contour search area generated by a character contour search area generation circuit 5 in FIG.

FIG. 4 is a diagram showing an image clipped by an image clipping circuit 8 in FIG.

FIG. 5 is a diagram showing an image clipped by a conventional character clipping device.

[Explanation of symbols]

 1 camera 2 AD conversion circuit 3 binarization circuit 4 closed area detection circuit 5 character outline search area generation circuit 6 character interval data storage circuit 7 character outline search circuit 8 image cutout circuit 9 circumscribed rectangle a video signal b grayscale image signal c 2 Quantized image signal d External rectangle coordinate signal e Character spacing data signal f Character outline search area signal g Character outline coordinate signal

Claims (1)

[Claims] 1. A camera for picking up an image of a character to be recognized, an AD conversion circuit for AD-converting a video signal input from the camera and outputting a grayscale image signal, and a predetermined value for inputting the grayscale image signal. The brighter part is "1",
The dark portion is a binarization circuit for converting it into a binarized image of "0", and a binarized image signal output from the binarization circuit is inputted and the area of "1" having a larger area than a predetermined value is inputted. A closed area detection circuit for calculating the outer shape coordinates of the circumscribed rectangle of the closed area, a character interval data storage circuit for storing character interval data, and the character interval storage circuit for the outer shape coordinates of the circumscribed rectangle output from the closed area detection circuit. A character contour search area generating circuit for generating a character contour search area expanded in the horizontal direction by the character interval data output from the character contour search area, and inputting the binarized image signal Character outline search circuit for calculating the character outline coordinates of the closed region of "1", and all closed regions of "1" searched from the binarized image output from the binarization circuit to the character outline search circuit Cut out a circumscribed rectangle containing Character segmentation apparatus which comprises a to the image extraction circuit.