US Patent 7719597 Distortion correction device and image sensing device provided therewith

Distortion data discretely stored in a distortion data memory 8 are read out by a selector 9 and fed to a signal processor 5. For each coordinate position, the signal processor 5 calculates an approximation formula representing an image height-distortion curve based on the distortion data fed thereto, and performs distortion correction based on the approximation formula.