Digital camcorder image stabilizer based on gray-coded bit-plane block matching
Huang-Cheng Chiang · Optical Engineering · 2001
We propose an efficient algorithm to eliminate the nonpleas- ing effect caused by involuntary hand movement of camera holders. In our approach, 1-bit gray-coded bit-plane block matching, instead of 8-bit gray-level block matching, is used to greatly simplify the computation of motion estimation. This computation saving makes possible a finer divi- sion of image frame and thus facilitates the employment of a much more robust procedure for motion decision. To deal with various interfering factors in motion estimation, the temporal information of each local mo- tion vector is also used to efficiently distinguish random-like movement from temporally correlated movement. To compensate for camera rota- tion, an affine model is used in the motion compensation unit without adding too much computation load. Having considered both program- ming flexibility and hardware efficiency, the motion decision unit and the motion compensation unit are coded in a microprocessor that intercon- nects with the stabilization hardware, which consists of the motion esti- mation unit and the digital zooming unit. A slightly simplified version of the proposed stabilizer is implemented on a field programmable gate array (FPGA) board. © 2001 Society of Photo-Optical Instrumentation Engineers.