Multi-registration in character recognition

• US 4,376,932 A
• Filed: 06/30/1980
• Issued: 03/15/1983
• Est. Priority Date: 06/30/1980
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Cassada, Thomas E.
• Primary Examiner(s): Boudreau, Leo H.
• Application Number:
  US06/164,130
• Time in Patent Office: 988 Days
• Field of Search: 340/146.3 Q, 340/146.3 AQ, 340/146.3 R, 340/146.3 MA, 340/146.2, 340/146.3 H, 364/515, 364/571, 364/728, 364/731, 364/819, 364/820, 358/105, 358/108, 358/109, 358/163, 356/388, 356/394, 356/398
• US Class Current: 382/216
• CPC Class Codes: G06T 3/00 Geometric image transformations in the plane of the image
• CPC Class Codes: G06V 10/10 Image acquisition document image scanning and transmission H04N1/00; control of digital cameras H04N23/60

Abstract

Optical character recognition in which registration of a stored, character image is changed from, for example, center to lower left depending on the individual character template or equivalent description against which the image is being compared. Accuracy is improved because the registration form used is one known to provide the greatest elements distinguishing the character of the template from the closest other character which might be presented.

Claims

1. A method of optical character recognition comprising:

(1) storing in data processing memory conditions defining an image,

(2) electronically comparing said stored image against a first identification model with said stored image in one perspective selected from perspectives referenced to a central area of said image and perspectives referenced to a border area of said image, and

(3) electronically comparing said stored image against a second identification model with said stored image in a different perspective selected from perspectives referenced to a central area of said image and perspectives referenced to a border area of said image, said second identification model having identification information differing essentially from the identification information of said first identification model.

2. The method as in claim 1 in which said one perspective is by reference to a corner of said image and said different perspective is by reference to the center of said image.

3. A method of optical character recognition comprising:

(1) storing in data processing memory conditions defining an image,

(2) electronically comparing said stored image against a first probabilistic tree which is an identification model for a plurality of characters with said stored image in a first perspective,

(3) electronically comparing said stored image against a second probabilistic tree which is an identification model for said plurality of characters with said stored image in a second perspective, and

(4) selecting the character identified by giving greater significance to the character identified by one of said trees having more elements of difference at the perspective it was identified than the character identified by the other of said trees over other characters to be identified.

4. The method as in claim 3 in which said first perspective is by reference to a corner of said image and said second perspective is by reference to the center of said image.

5. An electronic, optical character recognition device comprising:

(1) data processing memory means to store conditions defining an image corresponding to an image observed by electric means,

(2) means to locate said stored image by reference to a first registration perspective,

(3) means to locate said stored image by reference to a second registration perspective,

(4) a first identification model,

(5) a second identification model differing essentially in identification information from the identification information of said first identification model,

(6) means to compare said stored image in said first perspective against said first identification model,

(7) means to compare said stored image in said second perspective against said second identification model,

(8) registration selection means having a first condition when said first identification model is to be compared and having a second condition when said second identification model is to be compared,

(9) means responsive to said first condition of said registration selection means to enable said means to compare said image in said first perspective, and

(10) means responsive to said second condition of said registration selection means to enable said means to compare said image in said second perspective.

6. The optical character recognition device according to claim 5 in which said means to locate locates said stored image at least by reference to a corner of said image and by reference to the center of said image, and said first registration perspective is said location by reference to a corner and said second registration perspective is said location by reference to the center.

7. The optical character recognition device according to claim 6 in which said registration perspectives comprise center, bottom left, middle left, top left, top middle, top right, middle right, bottom right and bottom center, and said means to compare compares said image in each of said perspectives against at least one identification model different from the identification model to which all the other different perspectives of the image are compared.

8. An electronic, optical character recognition device comprising:

(1) data processing memory means to store conditions defining an image corresponding to an image observed by electric means,

(2) means to locate said stored image by reference to a first registration perspective,

(3) means to locate said stored image by reference to a second registration perspective,

(4) a first identification model,

(5) a second identification model,

(6) means to compare said stored image in said first perspective against said first identification model, said first identification model having more elements of difference than said second identification model over characters to be identified when both are compared in said first perspective,

(7) means to compare said stored image in said second perspective against said second identification model, said second identification model having more elements of difference than said first identification model over characters to be identified when both are compared in said second perspective,

(8) registration selection means having a first condition when said first identification model is to be compared and having a second condition when said second identification model is to be compared,

(9) means responsive to said first condition of said registration selection means to enable said means to compare said image in said first perspective, and

(10) means responsive to said second condition of said registration selection means to enable said means to compare said image in said second perspective.

9. The optical character recognition device according to claim 8 in which said means to locate locates said stored image at least by reference to a corner of said image and by reference to the center of said image, and said first registration perspective is said location by reference to a corner and said second registration perspective is said location by reference to the center.

10. The optical character recognition device according to claim 9 in which said registration perspectives comprise center, bottom left, middle left, top left, top middle, top right, middle right, bottom right and bottom center, and said means to compare compares said image in each of said perspectives against at least one identification model different from the identification model to which all the other different perspectives of the image are compared, each identification model being compared to the perspective for which it has more elements of difference than the other models over images to be identified other than that to be identified by the model being compared.

11. An electronic, optical character recognition device comprising:

(1) data processing memory means to store conditions defining an image corresponding to an image observed by electric means,

(2) means to locate said stored image by reference to a first registration perspective,

(3) means to locate said stored image by reference to a second registration perspective,

(4) a first probabilistic tree operative as an identification model to identify a plurality of characters,

(5) a second probabilistic tree operative as an identification model to identify said plurality of characters,

(6) means to compare said stored image in said first perspective against said first probabilistic tree and to signal the identity of a character identified,

(7) means to compare said stored image in said second perspective against said second probabilistic tree and to signal the identity of a character identified,

(8) registration selection means having a first condition when said first probabilistic tree is to be compared and having a second condition when said second identification model is to be compared,

(9) means responsive to said first condition of said registration selection means to enable said means to compare said image in said first perspective,

(10) means responsive to said second condition of said registration selection means to enable said means to compare said image in said second perspective, and

(11) means signalling one character identified in accordance with a selection favoring the result of the said means to compare which identified a character having more elements of difference than the character identified by the other said means to compare over other characters to be identified.

12. The optical character recognition device according to claim 11 in which said means to locate locates said stored image at least by reference to a corner of said image and by reference to the center of said image, and said first registration perspective is said location by reference to a corner and said second registration perspective is said location by reference to the center.