Browse Prior Art Database

Code Tracking

IP.com Disclosure Number: IPCOM000045788D
Original Publication Date: 1983-Apr-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 2 page(s) / 53K

Publishing Venue

IBM

Related People

Dinan, RF: AUTHOR [+4]

Abstract

A code pattern 1, characterized by the position and length of markings 2, is located and tracked by reference to a code zone indicator 3 and a segmented reference line 4.

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This is the abbreviated version, containing approximately 59% of the total text.

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Code Tracking

A code pattern 1, characterized by the position and length of markings 2, is located and tracked by reference to a code zone indicator 3 and a segmented reference line 4.

Document 5 is moved in the direction of arrow 6 past a solid-state scanner 7 which views a window 8 that is large with respect to the code pattern 1. The process starts when start tracking detector 12 recognizes the presence of code pattern 1 on document 5. When a scan is found to have more than a predetermined threshold percentage of black pels (picture elements), image data is loaded into profile register 11, and parallel scans of image data from scanner 7 are delivered through threshold circuitry 9 to a first-in, first-out (FIFO) memory
10. Once profile register 11 is loaded, offset calculation logic 14 is enabled to compute the distance 15 between the bottom edge of window 8 and the bottom edge of pattern 1 in terms of the number of scanner picture elements. This number is stored in an offset register 16 where it functions via line 17 to control the transfer of data from de-serializing shift register 18 to recognition buffer memory 19. Subsequent scans received from memory 10 are loaded, through a serializing register 23, into deserializing register 18 which shifts, pel by pel, until the calculated offset has been accounted for, whereupon line 17 enables transfer of the scan to memory 19.

To account for possible document skew, the calculated offset value is periodically updated...