LOW-COMPLEXITY MULTI-MODEL CNN IN-LOOP FILTER FOR AVS3

Convolutional neural network (CNN) has demonstrated powerful capabilities in many image/video processing tasks. In this paper, a low-complexity multi-model CNN in-loop filtering scheme is proposed for AVS3. Firstly, we carefully choose simplified ResNet as the lightweight single model of our proposed network. Subsequently, based on the selected single model, the multi-model iterative training framework is proposed to train a multi-model filter, where the network depth and the number of multi-models are customized for different ranges of bit rate to achieve the trade-off between model performance and computational complexity. Experimental results show that our method achieves on average 6.06% BD-rate reduction on Y component under all intra configuration. Compared to other CNN filters with comparable performance, our proposed multi-model filter can significantly reduce the decoder complexity, and the experimental results indicate that the decoding time can be saved by 26.6% on average.