A robust message passing based stereo matching kernel via system-level error resiliency

In this paper, we present an error resilient Markov random field (MRF) message passing based stereo matching hardware (HW) architecture. Previously, algorithmic noise tolerance (ANT) has been applied at the arithmetic level of the reparameterize unit and showed greatly enhanced robustness of message passing inference based architectures. In this work, correction was targeted at the system level to reduce correction overhead while maintaining performance. An erroneous FPGA based accelerator was employed as our emulation platform. Through relaxed synthesis, we show that timing errors occur within the message passing unit, and are successfully compensated. Error correction has been implemented at several hierarchical levels, including end of iteration, and the final depth map output. Significant enhancement in robustness is achieved with minimal correction overhead. Compared to HW error compensation at the arithmetic level, system level error compensation reduces overhead by more than 50 %, while maintaining stereo matching performance with only 3.8 % degradation.