05979763 is referenced by 266 patents and cites 25 patents.

Sub-pixel processing of image data representing a dataform, such as a 2D bar code, enables reading of dataforms including more data/smaller elements, without costly increases in sensor and memory capacity. Whole pixel processing is employed for pixel-per-element resolutions of two or better. Sub-pixel cell edge transition location in image data is enhanced by use of a dynamically implemented noise margin applied with bands of gray scale values designated within the envelope of applicable gray scale maximum and minimum values. Sub-pixel cell edge transition location employs selection of transition segments (subject to the noise margin) and determination of a dynamic threshold for each relevant transition segment. The intersection of the threshold and the transition segment is then indicative of the location of the cell edge transition along a sampling line crossing the dataform. The process is repeated for successive cell edges along image data sampling lines and for additional sampling lines crossing successive rows of dataform elements. Run length data representing cell edge transition locations is constructed and usable for dataform decoding.

Title
Sub-pixel dataform reader with dynamic noise margins
Application Number
8/543122
Publication Number
5979763
Application Date
October 13, 1995
Publication Date
November 9, 1999
Inventor
Angi Ye
Fort Myers
FL, US
Ynjiun P Wang
Fort Myers
FL, US
Agent
Benesch Friedlander Coplan & Aronoff
Assignee
Metanetics Corporation
FL, US
IPC
G06K 7/10
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