A Design Framework for Generating Energy-Efficient Accelerator on FPGA Toward Low-Level Vision

Low-level vision algorithms play an increasingly crucial role in a wide range of applications, such as biomedical, security, and autopilot. The low-level vision accelerators have also been extensively researched. As low-level vision is often deployed in embedded devices, its accelerators need to achieve high energy efficiency. Meanwhile, the broad application scenarios of low-level vision contribute to its rapid iteration. Designing energy-efficient accelerators for quickly evolving low-level vision algorithms demands substantial effort. Therefore, a design framework specifically tailored for the generation of low-level vision accelerators is urgently needed. In this article, we propose an end-to-end algorithm-hardware generation framework, EffiVision, on field-programmable gate array (FPGA), aimed at generating highly energy-efficient dedicated accelerators for low-level vision neural networks. EffiVision proposes a hardware template that features multiple parallelisms and large architecture exploration spaces specifically designed to accommodate the characteristics of low-level vision networks. Then, it employs activation-weight aware mixed-precision quantization and FPGA-aware NNLUTs to search the suitable hardware parameters within the hardware template, generating highly energy-efficient accelerators tailored for low-level vision networks. We used EffiVision to perform hardware generation for three low-level vision neural networks fast super-resolution convolutional neural network (FSRCNN), denoising convolutional neural network (DnCNN), and demosaicing convolutional neural network (DMCNN) on Xilinx FPGA development boards, achieving the best energy efficiencies of 174.9, 97.8, and 92.7 GOPS/W, respectively. The generated accelerators of FSRCNN and DnCNN are $1.11\times $ and $3.37\times $ more efficient than previous works.