Effective flicker removal from periodic intra frames and accurate flicker measurement

Flicker at periodic Intra-coded frames is a commonly seen video coding artifact, especially in low or medium bit rate coding. In this paper, a novel two-pass scheme is proposed to effectively remove I-frame flicker. The scheme involves a first pass of simplified P-frame coding to derive the no-flicker reference of the current frame, which is then taken as the target frame and coded with small quantization scales in the second pass of actual I-frame coding. Extensive experiment results demonstrate that our scheme successfully removes I-frame flicker, and greatly enhances the overall perceptual quality of coded video. Another contribution of this paper is a novel flicker distortion metric, which is superior than the existing metric, and can accurately measure flicker for any single frame.