Fast intra mode decision in HEVC using early distortion estimation

The latest video coding standard HEVC has the potential to rapidly conquer many areas of video compression due to the significant boost in coding efficiency compared to its predecessor. Unfortunately there is the drawback that this gain in efficiency comes at the expense of complexity. Encoders have to select the best possible coding mode from a huge set of available modes offered by the standard. In this paper the intra mode selection process is accelerated by early estimation of the distortion introduced by a certain mode, which may be applied in addition to other fast mode decision schemes. Due to the online adaptation of our proposed estimator, the approach is tolerant to different coding settings and input sequences. Using early distortion estimation results in a potential encoder speed-up of 24.83% on average, accompanied by an average bitrate increase of 2.92%.