Quality Enhancement of Screen Content Video using Dual-input CNN

In recent years, the video quality enhancement techniques have made a significant breakthrough, from the traditional methods, such as deblocking filter (DF) and sample additive offset (SAO), to deep learning-based approaches. While screen content coding (SCC) has become an important extension in High Efficiency Video Coding (HEVC), the existing approaches mainly focus on improving the quality of natural sequences in HEVC, not the screen content (SC) sequences in SCC. Therefore, we proposed a dual-input model for quality enhancement in SCC. One is the main branch with the image as input. Another one is the mask branch with side information extracted from the coded bitstream. Specifically, a mask branch is designed so that the coding unit (CU) information and the mode information are utilized as input, to assist the convolutional network at the main branch to further improve the video quality thereby the coding efficiency. Moreover, due to the limited number of SC videos, a new SCC dataset, namely PolyUSCC, is established. With our proposed dual-input technique, compared with the conventional SCC, BD-rates are further reduced 3.81% and 3.07%, by adding our mask branch onto two state-of-the-art models, DnCNN and DCAD, respectively.