Bar code scanning decoding
AssigneeSymbol Technologies, Inc.
InventorsDuanfeng He, Eugene Joseph
Life of this patent
Estimating the term…
Abstract
A two dimensional symbol is decoded by forming a binary image that includes the symbol. The binary is used to generate symbol margins for use in digitization. By using the binary image to determine the symbol margins, margins can be located efficiently and in the presence of symbol contrast variation caused by irregularities in the marked surface or light source angles. Digitization proceeds based on the determined margins.
Claims51
A method that decodes a symbol comprising:
- generating a contrast image from a gray scale image;
- transforming the contrast image into a binary image;
- determining an outline of the symbol using the binary image;
- and
- digitizing the symbol based on the outline and the gray scale image.
Computer readable media having computer executable instructions stored thereon for decoding a symbol, the instructions comprising:
- generating a contrast image from a gray scale image;
- transforming the contrast image into a binary image;
- determining an outline of the symbol using the binary image;
- and
- digitizing the symbol based on the outline and the gray scale image.
An apparatus for decoding a symbol comprising:
- means for generating a contrast image from a gray scale image;
- means for transforming the contrast image into a binary image;
- means for determining an outline of the symbol using the binary image;
- and
- means for digitizing the symbol based on the outline and the gray scale image.
An apparatus that decodes a symbol comprising:
- a front end processor that transforms the contrast image into a binary image and determines an outline of the symbol using the binary image;
- a digitizer that digitizes the symbol based on the outline;
- and
- wherein the front end processor includes a contour walker that traverses the boundary of the contrast image of the bar code and collects a set of data corresponding to characteristics of pixels located at or near the boundary of the bar code and wherein the front end processor binarizes the contrast image based on the set of data corresponding to the characteristics of pixels located at or near the boundary of the bar code.
Dependencies are inferred from the claim text.