Intra prediction using fully connected network for video coding

Traditional intra prediction methods exploit some fixed rules to generate prediction, which might not be adaptive enough to handle complicated contents. In this paper, we investigate applying deep neural network to improve the state-of-the-art intra prediction. Considering the characteristics of block-based video coding framework, we propose a fully connected network for intra prediction where all layers except non-linear ones are fully connected. In the proposed network, the inputs are multiple reference lines of the current block and the output is the prediction for the block. When compared with the traditional intra prediction method, the richer context of current block is exploited. For this reason, the proposed network is capable of providing more accurate prediction. Experimental results demonstrate the effectiveness of proposed network. When integrated into the HEVC reference software, the proposed method can achieve up to 3.3% bitrate saving and an average of 1.6% bitrate saving for 4K sequences.