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US 6,674,919 B1Granted
Method for determining the skew angle of a two-dimensional barcode
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsYue Ma, Jinhong Guo
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AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsYue Ma, Jinhong Guo
Estimating the term…
A method of calculating a skew angle for a two-dimensional barcode, in which the horizontal or vertical edges within the barcode are located, preferably using a finite state recognizer, and an edge array identifying the horizontal or vertical edges is generated. Next, the edge lines within the edge array are identified and traced, and any segments of edge lines within the edge array which are perpendicularly connected are separated. The slope for each edge line within the edge array is calculated, preferably using linear regression techniques. In the preferred embodiment, a discrete histogram of the slopes is generated and the skew angle is then set as the highest value within the discrete histogram. In a preferred embodiment, edge lines within the edge array which are located within a first predetermined threshold of each other are merged with each other and edge lines within the edge array having a length less than a second predetermined threshold are eliminated from the edge array to speed processing. Other techniques for analyzing the edge line slopes are also presented.
A method of calculating a skew angle for a bitmap of rows and columns of data pixels forming a two-dimensional barcode, comprising the steps of:
A method of calculating a skew angle for a bitmap of rows and columns of data pixels forming a two-dimensional barcode, comprising the steps of:
A method of calculating a skew angle for a bitmap of rows and columns of data pixels forming a two-dimensional barcode, comprising the steps of:
Dependencies are inferred from the claim text.