A fast intramode SKIP detection algorithm based on the rate-distortion (RD) cost for an interframe (P slices) is proposed for H.264/AVC video encoding. There are three types of intrapredictions according to profiles. These are 16×16 and 4×4 intrapredictions for luminance and an 8×8 intraprediction for chroma. For the high profile, an 8×8 intraprediction is added for luminance. The 4×4 prediction mode has nine prediction directions with four directions for 16×16 and 8×8 luma, and 8×8 chrominance. In addition to the intermode search procedure, an intramode search causes a significant increase in the complexity and computational load for an interframe. To reduce the computational load of the intramode search at the interframe, the rate-distortion (RD) costs of the neighborhood MBs for the current MB are used, and we propose an adaptive thresholding scheme for the intraSKIP extraction.
"Efficient intramode SKIP detection algorithm for H.264/AVC video encoder," Optical Engineering 45(9), 097008 (1 September 2006). https://doi.org/10.1117/1.2354444