US Patent 8717632 Image processing method, image processing device and scanner

An image processing method generally includes: obtaining a vanishing point on a curved surface in a two-dimension image; extracting all the straight line segments between a top contour line and a bottom contour line of the curved surface by the vanishing point; removing a perspective distortion to get parallel straight line segments; obtaining the lengths of the straight line segments, obtaining the true width of each of the straight line segments in a three-dimension space and the depth increment of the straight line segments according to the lengths; obtaining the expanded width of each straight line segment according to the true width and the depth increment; obtaining the total expanded width of the curved surface to transform it into a flat surface; transforming image contents on the curved surface onto the flat surface.