VLSI Design of Light-Field Factorization for Dual-Layer Factored Display

Abstract

This article introduces a VLSI design for light-field factorization, aimed at enhancing immersive 3-D visual experiences for computational light-field factored displays. The main design challenges are intensive memory-access demands and high computational complexity. Accordingly, we first propose half-block-based factorization (HBBF) and sparse ray sampling (SRS) to reduce DRAM bandwidth by 99% and SRAM size by 74%. Then, we devise integer hybrid quantization (INTH) to cut down computational logic by 41%, leading to improvements in die area and power efficiency. Finally, we fabricated a processor chip that incorporates 75.1 kB of SRAM and 5.9M logic gates using 40-nm CMOS technology. It can operate with three different performance modes: high quality (56.9 MPixel/s at 971 mW), balanced (62.5 MPixel/s at 442 mW), and low power (61.7 MPixel/s at 283 mW). Across these modes, its normalized energy ranges between 4.4 and 16.2 nJ/pixel. This implementation surpasses existing GPU platforms and offers an $85\times $ increase in processing speed and a $311\times $ reduction in power consumption. We also showcase a real-time computational 3-D display system with this chip, demonstrating its practical efficacy in computational 3-D display technology.