发明名称 |
Method and apparatus for vectorizing documents and symbol recognition |
摘要 |
An apparatus codes a scanned document locally representing each graphic element within a prescribed measure of accuracy by a trapezoidal approximation. The invention also includes a method for similarly coding a scanned document. The apparatus determines whether each scanned run is indicative of a Y- or lambda -junction, the termination of an old, or the commencement of a new graphic element, and whether a new linear approximation is necessary. The invention in a preferred embodiment recognizes symbols by determining the center of mass and maximum extremity of a symbol candidate, and comparing it to a reference library after normalizing with respect to scale, orientation and center of mass. In a preferred embodiment, an adaptive threshold parameter governs coding so as to reject noise and optimize a pair of linear predicters in a small number of scans. In a further preferred embodiment the accuracy of the linear predicters is refined so that the error is exponentially bounded.
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申请公布号 |
US4603431(A) |
申请公布日期 |
1986.07.29 |
申请号 |
US19830475037 |
申请日期 |
1983.03.14 |
申请人 |
ANA TECH CORPORATION |
发明人 |
GROVER, DAVID N.;KLECA, EUGENE A.;LIPKIE, CURTIS A. |
分类号 |
G06K9/46;G06K9/36;G06K9/80;G06T3/00;G06T9/20;H04N1/411;H04N1/417;(IPC1-7):G06K9/50 |
主分类号 |
G06K9/46 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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