Image analysis – Histogram processing – For setting a threshold
Patent
1987-02-25
1989-10-24
Boudreau, Leo H.
Image analysis
Histogram processing
For setting a threshold
382 20, G06K 900, G06K 970
Patent
active
048767301
ABSTRACT:
An optical character reader (OCR) using parallel state machines is provided wherein each state machine identifies a different character. Program tables for each of the state machines compare received bit strings of scanned data and compare them to positive and negative reference patterns in the state machines, wherein the positive reference patterns are tested for in sequence with advancement to test the next positive reference pattern only if the present positive reference pattern being tested for is present, and if none of at least one negative reference pattern is present. The OCR also detects and corrects skew by mathematically projecting a shadow of each character on the right margin of the page for each of a plurality of small incremental rotation angles for the characters. The rotation angle producing the sharpest and narrowest shadow effect is determined to be the angle at which the characters are skewed.
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Boudreau Leo H.
Daley Donald J.
Lundy Electronics & Systems, Inc.
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