Motion U-Net: Multi-cue Encoder-Decoder Network for Motion Segmentation

Detection of moving objects is a critical component of many computer vision tasks. Recently, deep learning architectures have been developed for supervised learning based moving object change detection. Some top performing architectures, like FgSegNet are single frame spatial appearance cue-based detection and tend to overfit to the training videos. We propose a novel compact multi-cue autoencoder deep architecture, Motion U-Net (MU-Net) for robust moving object detection that generalizes much better than FgSegNet and requires nearly 30 times fewer weight parameters. Motion and change cues are estimated using a multi-modal background subtraction module combined with flux tensor motion estimation. MU-Net was trained and evaluated on the CDnet-2014 change detection challenge video sequences and had an overall F-measure of 0.9369. We used the unseen SBI-2015 video dataset to assess generalization capacity where MU-Net had an F-measure of 0.7625 while FgSegNet_v2 was 0.3519, less than half the MU-Net accuracy. The source code of the Motion U-Net is available at https://github.com/CIVA-Lab/Motion-U-Net.