Tamed Warping Network for High-Resolution Semantic Video Segmentation
This work addresses accuracy drops in real-time semantic video segmentation for applications like autonomous driving, representing an incremental improvement over existing warping-based methods.
The paper tackles the problem of accuracy loss in fast semantic video segmentation due to warping errors by proposing a novel framework with a correction stage, resulting in a significant accuracy increase from 67.3% to 71.6% on Cityscapes while maintaining high speed.
Recent approaches for fast semantic video segmentation have reduced redundancy by warping feature maps across adjacent frames, greatly speeding up the inference phase. However, the accuracy drops seriously owing to the errors incurred by warping. In this paper, we propose a novel framework and design a simple and effective correction stage after warping. Specifically, we build a non-key-frame CNN, fusing warped context features with current spatial details. Based on the feature fusion, our Context Feature Rectification~(CFR) module learns the model's difference from a per-frame model to correct the warped features. Furthermore, our Residual-Guided Attention~(RGA) module utilizes the residual maps in the compressed domain to help CRF focus on error-prone regions. Results on Cityscapes show that the accuracy significantly increases from $67.3\%$ to $71.6\%$, and the speed edges down from $65.5$ FPS to $61.8$ FPS at a resolution of $1024\times 2048$. For non-rigid categories, e.g., ``human'' and ``object'', the improvements are even higher than 18 percentage points.