Distortion Propagation Based Quantization Parameter Cascading Method for Screen Content Video Coding

Screen content video (SCV) is generated by computers, including animation, texts and graphics. SCV contains continuous static frames and many scene changes, making SCV different from conventional camera captured video (CCV) in terms of temporal characteristic. Therefore, conventional quantization parameter (QP) cascading method may not be efficient for SCV. In this paper, a distortion propagation based QP cascading method is proposed for SCV. The special temporal characteristic of SCV is considered and the distortion propagation of every coding tree unit (CTU) is measured. Based on the CTU level distortion propagation, the improved QP cascading method is designed. Experimental results show that compared with other methods, the proposed could achieve better rate distortion (RD) performance and less encoding time.