Study on algorithm for panoramic image basing on high sensitivity and high resolution panoramic surveillance camera

Abstract

A single panoramic annular lens optical system and high-sensitivity, high-resolution CCD sensors form the basis of a 360° panoramic night vision image processing hardware platform. The unwrapped and correcting algorithm based on Coordinate Rotation Digital Computer (CORDIC) and bilinear interpolation algorithm was presented in this paper, with the purpose of processing dynamic panoramic annular image. The night vision image enhancement algorithm, based on adaptive piecewise linear gray transformation (APLGT) and Laplacian of Gaussian (LOG) edge detection, were given. An original annular panoramic image captured by panoramic annular lens (PAL) can be unwrapped and corrected to conventional rectangular image without distortion, which is much more coincident with people's vision. APLGT algorithm can be adaptively truncate the image histogram on both ends to obtain a smaller dynamic range so as to enhance the contrast of the night vision image. LOG algorithm can be propitious to find and detect dim small targets in night vision circumstance. The algorithm for panoramic image processing is modeled by VHDL and implemented in FPGA. The experimental results show that the proposed panoramic image algorithm for unwrapped and distortion correction has the lower computation complexity and the architecture for dynamic panoramic image processing has lower hardware cost and power consumption.