An embedded camera lens distortion correction method for mobile computing applications

This paper describes a lens geometric and photometric distortion correction method to obtain a high quality image with low cost digital cameras. Lens geometric distortion coefficient of a digital camera is estimated using a simplified camera calibration technique, which is extended to calibration-free estimation method. Based on the estimate of the lens geometric distortion coefficient, image warping adapted for DSP architecture is applied. Photometric distortion, on the other hand, is corrected by a nonlinear model fitting of a proposed photometric distortion model function. Light intensity profile distribution is obtained without precisely controlled illumination and memory requirement is considerably reduced compared with traditional lookup table (LUT) methods.