Rolling Shutter Distortion
Li-Wen Chang , Chia-Kai Liang, Homer H. Chen
The electronic rolling shutter approach found in most low-end CMOS image sensors collects image data row by row, analogous to an open slit that scans over the image sequentially. Each row integrates light when the slit passes over it. Therefore, the scanlines of the image are not exposed at the same time. This sensor architecture creates a geometric distortion, known as the rolling shutter effect, for moving objects. We address this problem by using digital image processing techniques.
A mathematical model of the rolling shutter is developed. The distortion is proportional to the relative image motion between the objects and the camera.
The motion is determined by block-based motion estimation, and a polynomial fitting is applied to the result ing motion data. The smoothed motion data are then used to align the scanlines. The algorithm can be generalized to other complicated cases. We are developing a more robust system to estimate the motion and to imporve the correction result. This work has been reported in [ISCOM2005] and [VCIP2005]. (Exhibition)
ISCOM2005 L. Chang, C.-K. Liang, H. H. Chen, “Analysis and correction of rolling shutter distortion for CMOS image sensor arrays,” The 8th International Symposium on Communications, Kaohsiung, Taiwan, Nov. 2005
VCIP2005 C.-K. Liang and H. H. Chen, “Rolling shutter distortion correction,” Proc. Visual Communications and Image Processing, Bejing, China, Jul. 2005