SegBlocks: Block-Based Dynamic Resolution Networks for Real-Time Segmentation
This work offers a better accuracy versus complexity trade-off for real-time semantic segmentation, which is beneficial for applications requiring efficient on-device processing.
This paper tackles the problem of high computational cost in neural networks for real-time segmentation by dynamically adjusting processing resolution based on image region complexity. The method reduces SwiftNet-RN18's floating-point operations by 60% and increases inference speed by 50%, with only a 0.3% decrease in mIoU accuracy on Cityscapes.
SegBlocks reduces the computational cost of existing neural networks, by dynamically adjusting the processing resolution of image regions based on their complexity. Our method splits an image into blocks and downsamples blocks of low complexity, reducing the number of operations and memory consumption. A lightweight policy network, selecting the complex regions, is trained using reinforcement learning. In addition, we introduce several modules implemented in CUDA to process images in blocks. Most important, our novel BlockPad module prevents the feature discontinuities at block borders of which existing methods suffer, while keeping memory consumption under control. Our experiments on Cityscapes, Camvid and Mapillary Vistas datasets for semantic segmentation show that dynamically processing images offers a better accuracy versus complexity trade-off compared to static baselines of similar complexity. For instance, our method reduces the number of floating-point operations of SwiftNet-RN18 by 60% and increases the inference speed by 50%, with only 0.3% decrease in mIoU accuracy on Cityscapes.