Method and device for recognizing a specific pattern

• US 4,115,761 A
• Filed: 02/07/1977
• Issued: 09/19/1978
• Est. Priority Date: 02/13/1976
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Matsuoka, Shinji, Ueda, Hirotada, Ejiri, Masakazu, Uno, Takeshi, Ikeda, Sadahiro
• Primary Examiner(s): Boudreau, Leo H.
• Application Number:
  US05/766,486
• Time in Patent Office: 589 Days
• Field of Search: 340/146.3 AE, 340/146.3 AC, 340/146.3 AH, 340/146.3 AQ, 340/146.3 H, 340/146.3 F
• US Class Current: 382/203
• CPC Class Codes: G06V 10/44 Local feature extraction by analysis of parts of the pattern, e.g. by detecting edges, contours, loops, corners, strokes or intersections; Connectivity analysis, e.g. of connected components

Abstract

This method for recognizing a specific pattern is characterized in a process of extracting feature parts wherein one or more certain feature parts of specific shape are extracted from an input pattern; the next feature part is then extracted from an extracting area which is determined from the position on the input pattern where a previous feature part was extracted; and in case that the next feature part fails to be extracted from the extracting area so determined, the initial condition is restored thereby extracting the feature part by successively limiting extracting areas.

Claims

1. In a device for recognizing the presence of a specific object pattern on an information pattern, a recognition method comprising:

a first step of inputting the information pattern including an object pattern having at least a first and a second feature parts of specific shape;

a second step of extracting information from said information pattern indicating the presence of said first feature part of specific shape and its position coordinates on said information pattern;

a third step of determining a certain extracting area on the basis of said position coordinate information of said first feature part of specific shape and extracting said second feature part of specific shape existing in said extracting area and the position coordinates therefor;

a fourth step of determining at least a first coordinate identifying the position of a third feature part from the position coordinates of at least one of said first and second feature parts;

a fifth step of sequentially cutting out partial patterns in an area related to said first coordinate determined in said fourth step from among the information picked up in said first step and determining the position coordinates for these partial patterns;

a sixth step of extracting the presence and at least a second coordinate identifying the position of said third feature part from among said sequentially cut out partial patterns;

a seventh step of recognizing feature parts contained in said sequentially cut out partial patterns and generating a signal representative thereof; and

an eighth step of selecting a signal output generated in said seventh step as the desired character recognition signal when the position coordinates of said sequentially cut out partial pattern in which said feature recognized in said seventh step is located substantially matches the position coordinates of said third feature part determined in said fourth and sixth steps.

2. A recognition method as defined in claim 1, further comprising:

a ninth step of restoring the initial condition and extracting said first feature of specific shape when said second feature part of specific shape fails to be extracted from said extracting area during said third step.

3. A pattern recognition device comprising

input means for inputting an information pattern including an object pattern having a plurality of feature parts of specific shape,

plurality of extracting means for extracting information indicating the presence of a feature part of specific shape in a certain extracting area of the information pattern from said input means and its position on said information pattern,

sequence control means for receiving the information of the feature part of specific shape extracted by said extracting means, and selectively causing a given one of said extracting means to operate next, and

area control means for determining, from the position information extracted by said extracting means, said next certain extracting area for said extracting means.

4. A pattern recognition device comprising

first means for inputting an information pattern including an object pattern having at least one character pattern within a mark of a specific shape,

second means for extracting, from the information pattern from said first means, information indicating the presence of said mark and its position on said information pattern,

third means for determining at least a first coordinate identifying the position of a character pattern on said information pattern from the position of said mark,

fourth means for sequentially cutting out partial patterns in an area related to said first coordinate determined by said third means from among the information picked up by said first means and determining the position coordinates for said partial patterns,

fifth means for extracting the presence and at least a second coordinate identifying the position of said character pattern from among said sequentially cut out partial patterns,

sixth means for recognizing character patterns contained in said sequentially cut out partial patterns and generating a signal representative thereof, and

seventh means for selecting the signal output from said sixth means as the desired character recognition signal when the position coordinates of said sequentially cut out partial pattern in which is located said character recognized by said sixth means substantially match the position coordinates of said character pattern determined by said third and fifth means.

5. A pattern recognition device of claim 4 wherein said first means comprises a pickup means.

6. A pattern recognition device of claim 5 wherein said second means comprises means for obtaining the inclination of said mark, and said device further comprises a fourth means for compensating, by means of information indicating the inclination of said mark obtained by said second means, the inclination of the mark on the image picked up by said pickup means.

7. A pattern recognition device of claim 6 wherein said fourth means comprises a Wallaston prism.

8. A pattern recognition device of claim 4 wherein said second means comprises a fifth means for extracting the position of an end of said mark and a sixth means for extracting the center position in the width direction of said mark.

9. A pattern recognition device for recognizing the presence of a specific object pattern having at least a first and a second feature parts of specific shapes on an information pattern comprising:

first means for sequentially picking up the information pattern in a predetermined order;

second means for sequentially cutting out at least a first and a second partial patterns from among the information pattern picked up by said first means and determining position coordinates for said first and second partial patterns;

third means for extracting the presence of the first feature part and its position coordinates on the information pattern from the first partial sequentially cut out by said second means;

fourth means for extracting the presence of the second feature part and its position coordinates from the second partial pattern cut out by said second means when the position coordinates of the second partial pattern on the information pattern are in a first area related to the position coordinates of the first feature part thereon extracted by said third means;

fifth means for determining at least a first coordinate identifying the position of a third feature part from the position coordinates of at least one of said first and second feature parts;

sixth means for sequentially cutting out third partial patterns in an area related to said first coordinate determined by said fifth means from among the information picked up by said first means and determining the position coordinates for said third partial patterns;

seventh means for extracting the presence and at least a second coordinate identifying the position of said third feature part from among said sequentially cut out third partial patterns;

eighth means for recognizing feature parts contained in said sequentially cut out third partial patterns by matching them to known feature parts and generating a signal representative thereof; and

ninth means for selecting the signal output from said eighth means as the desired character recognition when the position coordinates of said sequentially cut out third partial pattern in which said feature recognized by said eighth means is located substantially match the position coordinates of said third feature part determined by said fifth and seventh means.

10. A pattern recognition device according to claim 9, further comprising:

tenth means for determining the inclination of the object pattern in said information pattern from at least one of the position of the first and second feature parts; and

eleventh means for compensating the inclination of the object pattern picked up by said first means by means of the inclination information received from said tenth means.

11. A pattern recognition device according to claim 10, wherein said second means includes shift register means.

12. A pattern recognition device as defined by claim 11, wherein said eleventh means comprises a Wallaston prism.

13. A pattern recognition device as defined in claim 10, wherein said position coordinates for said third partial patterns are center coordinates for said third partial patterns.