Method for 2-D affine transformation of images

摘要

Affine image transformations are performed in an interleaved manner, whereby coordinate transformations and intensity calculations are alternately performed incrementally on small portions of an image. The pixels are processed in rows such that after coordinates of a first pixel are determined for reference, each pixel in a row, and then pixels in vertically adjacent rows, are processed relative to the coordinates of the previously processed adjacent pixels. After coordinate transformation to produce affine translation, rotation, skew, and/or scaling, intermediate metapixels are vertically split and shifted to eliminate holes and overlaps. Intensity values of output metapixels are calculated as being proportional to the sum of scaled portions of the intermediate metapixels which cover the output pixels respectively.