Real-Time FPGA-Based Panoramic Unrolling of High-Resolution Catadioptric Omnidirectional Images

A new generation of optical devices that generate images covering 360 degree field of view, namely catadioptric cameras, is slowly emerging. Because of the concentric annular distortion, the omnidirectional images need to be transformed into panoramic images. In omnidirectional visual surveillance systems, it is a challenge to realize panoramic unrolling in real time, especially for high-resolution applications. In this paper, a FPGA implementation of pipeline structure is proposed, which uses lookup tables to replace complex calculations to guarantee high speed performance and low cost of hardware resources. Notably, a novel strategy of ldquoblock prefetchingrdquo is proposed. The experimental results show that the implementation can realize real-time unrolling of 1024times1024 omnidirectional images into 3200times768 panoramic images at 24.672 ms per frame. The developed FPGA design can be easily inserted into the digital interface of the current omnidirectional cameras.