Method and apparatus for non-affine image warping

A circuit for performing a non-affine image transformation on a source image comprised of a plurality of points having at least X and Y values comprising:

• first storage means for storing said source image;
• second storage means for storing an X displacement table, the entries of said X displacement table representing the displacement of each point of said source image in an X direction resulting from said non-affine transformation;
• third storage means for storing a Y displacement table, the entries of said Y displacement table representing the displacement of each point of said source image in a Y direction resulting from said non-affine transformation;
• first resampling means coupled to said first and second storage means for resampling said source image with said X displacement table to generate an intermediate image, said intermediate image stored in a fourth storage means;
• second resampling means coupled to said second and third storage means for resampling said Y displacement table with said X displacement table to generate an intermediate Y displacement table, said intermediate Y displacement table stored in a fifth storage means;
• third resampling means coupled to said fourth and fifth storage means for resampling said intermediate image with said intermediate Y displacement table to generate a destination image representing said non-affine transformation of said source image, said destination image stored in a sixth storage means.

A method for performing a non-affine image transformation on a source image comprised of a plurality of points having at least X and Y values comprising the steps of:

• defining a warp mesh representing said non-affine transformation of said source image;
• defining an X displacement table, the entries of said X displacement table representing the displacement of each point of said source image in an X direction resulting from said non-affine transformation;
• defining a Y displacement table, the entries of said Y displacement table representing the displacement of each point of said source image in a Y direction resulting from said non-affine transformation;
• resampling said source image with said X displacement table to generate a first intermediate image of surface area S1;
• resampling said source image with said Y displacement table to generate a second intermediate image of surface area S2;
• transposing said source image and said X and Y displacement tables, and resampling said transposed source image with said transposed X displacement table to generate a third intermediate image of surface area S3;
• resampling said transposed source image with said transposed Y displacement table to generate a fourth intermediate image of surface area S4;
• when S1 is greater than S2, S3 and S4, resampling said Y displacement table with said X displacement table to generate an intermediate Y displacement table, then resampling said first intermediate image with said intermediate Y displacement table to generate a destination image representing said non-affine transformation of said source image;
• when S2 is greater than S1, S3 and S4, resampling said X displacement table with said Y displacement table to generate an intermediate X displacement table, then resampling said second intermediate image with said intermediate X displacement table to generate a destination image representing said non-affine transformation of said source image;
• when S3 is greater than S1, S2 and S4, resampling said transposed Y displacement table with said transposed X displacement table to generate a transposed intermediate Y displacement table, then resampling said third intermediate image with said transposed intermediate Y displacement table to generate a destination image representing said non-affine transformation of said source image;
• when S4 is greater than S1, S2 and S3, resampling said transposed X displacement table with said transposed Y displacement table to generate a transposed intermediate X displacement table, then resampling said fourth intermediate image with said transposed intermediate X displacement table to generate a destination image representing said non-affine transformation of said source image.