A PATTERN RECOGNITION DEVICE INCLUDING MEANS FOR COMPENSATING FOR REGISTRATION ERRORS

• US 3,727,183 A
• Filed: 05/11/1971
• Issued: 04/10/1973
• Est. Priority Date: 08/16/1967
• Status: Expired due to Term

• Current Assignee: Christopher Archibald Gordon Lemay
• Original Assignee: Christopher Archibald Gordon Lemay
• Inventors: LeMay, Christopher Archibald Gordon
• Primary Examiner(s): Wilbur, Maynard R.
• Assistant Examiner(s): Boudreau, Leo H.
• Application Number:
  US05/142,378
• Time in Patent Office: 700 Days
• Field of Search: 340/146.3 178/6.8 250/220
• US Class Current: 382/218
• CPC Class Codes: G06V 30/10 Character recognition
• CPC Class Codes: G06V 30/146 Aligning or centring of the image pick-up or image-field

Abstract

A pattern recognition device according to the invention comprises means for scanning an input pattern to derive a representation thereof, means for comparing the representation with each representation of a plurality of known patterns to identify the known pattern most similar to the input pattern and means for deriving an error signal representing a registration error between the input pattern and the known pattern most similar thereto. Means are then provided for utilizing the error signals to produce successive modifications of the scanning waveforms of the scanning means in dependence upon the error signals to tend to reduce the error signal.

Claims

1. A pattern recognition device including:

a. means for scanning an input pattern to be recognized to derive therefrom a representation of said input pattern, b. means for generating scanning waveforms for said scanning means, c. storage means conditioned to store representations of a plurality of known patterns, d. means adapted to compare said representation of said input pattern with each of said representations of known patterns to select a known pattern according to a selection criterion, e. means responsive to said representation of said input pattern and the representation of said selected known pattern adapted to derive an error signal which is related to the extent of a rEgistration error between the representation of said input pattern and the representation of said selected known pattern, f. means adapted to modify the scanning waveforms for said scanning means in a sense tending to reduce said error signal, and g. means adapted to control the operation of the device so as to cause the scanning operation effected under the control of the modified scanning waveforms to be followed by further operations of the comparing means, and of the error signal deriving means until a degree of correspondence between the representation of the input pattern and the last selected known pattern is obtained which is greater than a threshold value.

2. A device according to claim 1 in which said means for generating said scanning waveforms includes means for generating a raster of diagonal lines.

3. A device according to claim 1 wherein said means adapted to derive an error signal comprises means adapted to derive different error signals which are related to the extent of registration errors of different kinds between the representation of said input pattern and the representation of the selected known pattern, and said means adapted to modify comprises means for utilizing said different error signals to produce different modifications of said scanning waveforms.

4. A device according to claim 3 wherein said means adapted to derive different error signals includes:

a. means for defining different areas of the scanning field of said scanning means, b. means for producing signals which are related to the extent of the misregistration of the representations of said input and said selected known pattern in each of said different areas, and c. means for differently combining said signals which are related to the extent of the misregistration thereby to generate said different error signals.

5. A device according to claim 4 wherein said means for defining different areas includes means for utilizing said scanning waveforms to generate selected signals representing different areas of the scanning field, and said means for producing signals which are related to the extent of the misregistration includes means for utilizing said selecting signals.

6. A device according to claim 1 including means adapted to generate an error signal which is related to the extent of a shift of position.

7. A device according to claim 1 including means adapted to generate an error signal which is related to the extent of a difference of size.

8. A device according to claim 1 including means adapted to generate an error signal which is related to the extent of an error in parallelism.

9. A pattern recognition device including:

a. means for scanning an input pattern to be recognized to derive therefrom a representation of said input pattern, b. means for generating scanning waveforms for said scanning means, c. storage means conditioned to store representations of a plurality of known patterns, d. means adapted to compare said representation of said input pattern with each of said representations of known patterns to select a known pattern according to a selection criterion, e. means for defining different areas of the scanning field of said scanning means, f. means for producing signals which are related to the extent of the misregistration between the representation of said input pattern and the representation of said selected known pattern in each of said different areas, g. means for differently combining said signals which are related to the extent of the misregistration thereby to generate different error signals which are related to the extent of registration errors of different kinds between the representation of said input pattern and the representation of said selected known pattern, h. means adapted to modify the scanning waveforms for said scanning means in a sense tending to reduce said different error signals, and i. means adapted to control the operation of the device so as to cause the scanning operation effected under the control of the modified scanning waveforms to be followed by further operations of the comparing means and of the error signal deriving means until a degree of correspondence between the representations of the input pattern and the last selected known pattern is obtained which is greater than a threshold value.