An Efficient High-Throughput Structured-Light Depth Engine
Yichuan Bai, Mingzhe Jiang, Qingyu Zhu, Xiaoliang Chen, Yuan Du, Li Du, Zhongfeng Wang · IEEE Transactions on Very Large Scale Integration (VLSI) Systems · 2022
In this article, an efficient high-throughput depth engine is proposed to generate high-quality 3-D depth maps for speckle-pattern structured-light depth cameras. A dynamic-binarization (DB) method is introduced with a significant reduction of computational complexity in contrast to the sum-of-absolute-distance (SAD) method. The depth map evaluation shows good robustness compared with other window-based correlation methods. Parallel architecture and reuse of intermediate results are employed for efficient hardware implementation. Our design is verified on a field-programmable gate array (FPGA) and implemented in the SMIC 55-nm CMOS technology, achieving a frame rate of 1731.77 fps ($640\times480$) with an area efficiency of 3.75 fps/KGE. The proposed engine shows a$2.71\times $promotion of area efficiency in contrast to the SAD-based implementation. In addition, the subpixel estimation algorithm deployed in postprocessing is optimized for efficient hardware implementation, reducing the gate count by 69.2% without significant performance loss.