Image analysis – Image transformation or preprocessing – Measuring image properties
Reexamination Certificate
2006-11-28
2006-11-28
Mehta, Bhavesh M (Department: 2624)
Image analysis
Image transformation or preprocessing
Measuring image properties
C382S282000, C382S284000, C358S538000, C358S540000
Reexamination Certificate
active
07142727
ABSTRACT:
A parallel, non-iterative, memory efficient method of determining image skew. A document skew angle is determined from a fast scan second order moment data set and a slow scan second order moment data set. A slow scan second order moment data set can be generated by receiving a current scanline of image data, updating columns sums for a set of rotation angles using scanlines within a buffer comprising a band having a predetermined number B of scanlines, and updating the buffer with the current scanline. A fast scan second order moment data set is generated by projecting a plurality of pixels within each scanline of image data received to a first rotation angle wherein the plurality pixels project onto M rows; updating M memory locations, wherein each one of the M memory locations corresponds to one of the M rows and wherein each memory location is updated using pixels projecting onto the corresponding row whereby one of the M memory locations contains a completed row; and adding the square of the completed row sum to a moment accumulator.
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Notovitz William
Schweid Stuart Alan
Eipert William
Mehta Bhavesh M
Tucker Wes
Xerox Corporation
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