Browse Prior Art Database

Slanted Supplementary Scan

IP.com Disclosure Number: IPCOM000074034D
Original Publication Date: 1971-Mar-01
Included in the Prior Art Database: 2005-Feb-23
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Porwit, EI: AUTHOR [+2]

Abstract

In optical character readers, a conflict can exist between resolving handwritten numerals 7 and 9. The original 7-9 supplementary scan technique employed a vertical scan as shown in B taken through the character after a contour analysis resulted in a 7-9 conflict. The conflict was resolved by detecting additional information about the character during the additional scan.

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Slanted Supplementary Scan

In optical character readers, a conflict can exist between resolving handwritten numerals 7 and 9. The original 7-9 supplementary scan technique employed a vertical scan as shown in B taken through the character after a contour analysis resulted in a 7-9 conflict. The conflict was resolved by detecting additional information about the character during the additional scan.

The slanted supplementary scan represents an improvement in this additional scan technique for resolving 7-9 conflicts. As shown in the logic diagram A, after recognition of a 7-9 conflict, the scanner beam is moved simultaneously down vertically at 4000 mils per mill-second and left horizontally at 1000 mils per millisecond. This results in the vertical scan path as shown in C. The slanted scan technique yields a much lower chance for detecting a 7 as a 9 or a 9 as a 7 than the normal vertical scan. This can be seen by comparing distance ::ABin C with distance A'B' in B. The slanted scan of C results in more distance between the scan path point A and the point character B. A normally written character will cross the point B but an abnormally written character could touch or cross the normal scan path A'. This results in detecting an additional erroneous hit and possibly a 7 (1 hit) being detected as a 9 (2 hits). Conversely, if the top of the character were written to the right of center, the normal scan could possibly miss the hit and a 9 (2 hits) could be erroneousl...