Browse Prior Art Database

Line Start Verification for Optical Pattern Recognition

IP.com Disclosure Number: IPCOM000086121D
Original Publication Date: 1976-Jul-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Related People

Benson, GG: AUTHOR

Abstract

For unconstrained environments such as the recognition of characters with a hand-held wand scanner, it is difficult to determine where a line of characters actually starts. The scanner input may include background noise, label edges, noncharacter patterns, specular reflections on set down, etc.

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Line Start Verification for Optical Pattern Recognition

For unconstrained environments such as the recognition of characters with a hand-held wand scanner, it is difficult to determine where a line of characters actually starts. The scanner input may include background noise, label edges, noncharacter patterns, specular reflections on set down, etc.

Verification system 10, Fig. 1, routes incoming video data VID to a conventional recognition unit 11 whose output, for this purpose, is a single signal indicating that some valid character has been recognized. Detectors 20-40 process VID to produce signals representing vertical, horizontal and noncharacter noise patterns, respectively. When the proper conditions are fulfilled, AND gate 12 (the circle represents an inverting input) sets latch 13, whose output LINE indicates the presence of a valid print line. Latch 13 is reset by end-of-line logic 14.

Fig. 2 shows vertical detector 20 in greater detail. Boolean logic 21 sets latch 22 upon a first vertical discontinuity in VID. Thereafter, a valid-character recognition signal TREF (from unit 11) enables AND 23 to set latch 24. If logic 25 then senses a second vertical discontinuity, AND 26 sets latch 27 to produce the output signal VERT. This sequence must occur in a single scan, since timing signal EOS resets latches 22, 24 and 27 at the end of every scan.

Detector 30, Fig. 3, includes logic 31 and 32 for detecting horizontal discontinuities to the left and right of bl...