Parameter Reduction of Kernel-Based Video Frame Interpolation Methods Using Multiple Encoders

Video frame interpolation synthesises a new frame from existing frames. Several approaches have been devised to handle this core computer vision problem. Kernel-based approaches use an encoder-decoder architecture to extract features from the inputs and generate weights for a local separable convolution operation which is used to warp the input frames. The warped inputs are then combined to obtain the final interpolated frame. The ease of implementation of such an approach and favourable performance have enabled it to become a popular method in the field of interpolation. One downside, however, is that the encoder-decoder feature extractor is large and uses a lot of parameters. We propose a Multi-Encoder Method for Parameter Reduction (MEMPR) that can significantly reduce parameters by up to 85% whilst maintaining a similar level of performance. This is achieved by leveraging multiple encoders to focus on different aspects of the input. The approach can also be used to improve the performance of kernel-based models in a parameter-effective manner. To encourage the adoption of such an approach in potential future kernel-based methods, the approach is designed to be modular, intuitive and easy to implement. It is implemented on some of the most impactful kernel-based works such as SepConvNet, AdaCoFNet and EDSC. Extensive experiments on datasets with varying ranges of motion highlight the effectiveness of the MEMPR approach and its generalisability to different convolutional backbones and kernel-based operators.