Fisheye lens distortion correction on multicore and hardware accelerator platforms

摘要

Wide-angle (fisheye) lenses are often used in virtual reality and computer vision applications to widen the field of view of conventional cameras. Those lenses, however, distort images. For most real-world applications the video stream needs to be transformed, at real-time (20 frames/sec or better), back to the natural-looking, central perspective space. This paper presents the implementation, optimization and characterization of a fisheye lens distortion correction application on three platforms: a conventional, homogeneous multicore processor by Intel, a heterogeneous multicore (Cell BE), and an FPGA implementing an automatically generated streaming accelerator. We evaluate the interaction of the application with those architectures using both high- and low-level performance metrics. In macroscopic terms, we find that todays mainstream conventional multicores are not effective in supporting real-time distortion correction, at least not with the currently commercially available core counts. Architectures, such as the Cell BE and FPGAs, offer the necessary computational power and scalability, at the expense of significantly higher development effort. Among these three platforms, only the FPGA and a fully optimized version of the code running on the Cell processor can provide realtime processing speed. In general, FPGAs meet the expectations of performance, flexibility, and low overhead. General purpose multicores are, on the other hand, much easier to program.