Time Multiplexed VLSI Architecture for Real-Time Barrel Distortion Correction in Video-Endoscopic Images

A low-cost very large scale integration (VLSI) implementation of real-time correction of barrel distortion for video-endoscopic images is presented in this paper. The correcting mathematical model is based on least-squares estimation. To decrease the computing complexity, we use an odd-order polynomial to approximate the back-mapping expansion polynomial. By algebraic transformation, the approximated polynomial becomes a monomial form which can be solved by Hornor´s algorithm. With the iterative characteristic of Hornor´s algorithm, the hardware cost and memory requirement can be conserved by time multiplexed design. In addition, a simplified architecture of the linear interpolation is used to reduce more computing resource and silicon area. The VLSI architecture of this paper contains 13.9-K gates by using a 0.18 μm CMOS process. Compared with some existing distortion correction techniques, this paper reduces at least 69% hardware cost and 75% memory requirement.