InvFlow: Involution and multi-scale interaction for unsupervised learning of optical flow

The convolution neural network is still the main tool for extracting the image features and the motion features for most of the optical flow models. The convolution neural networks cannot model the long-range dependencies, and more details are lost in deeper layers. All the deficiencies in the extracted features affect the estimated flow. Therefore, in this work, we concentrated on optimizing the convolution neural network in both the encoder and decoder parts to improve the image and motion features. To enhance the image features, we utilize the involution to provide rich features and model the long-range dependencies. In addition, we propose a Multi-Scale-Interaction module which utilizes the self-attention to make an interaction between the feature scales to avoid detail loss. Additionally, we propose a Motion-Features-Optimization block that utilizes the deformable convolution to enhance the motion features. Our model achieves the state-of-the-art performance on Sintel and KITTI 2015 benchmarks.