Fast HEVC intra mode decision using matching edge detector and kernel density estimation alike histogram generation

Intra coding algorithm in High Efficiency Video Coding employs up to 35 directional prediction modes. Upon the end of alleviating the intra encoding complexity, we proposed the candidate mode selection algorithm from analyzing the textures of the source image block. Considering the fine difference between the neighboring prediction directions, we devise the fix-point arithmetic based edge detector, which improves the direction detection accuracy as compared with the typical previous works while maintaining the low computational overhead. To improve the robustness of the edge direction statistics, we further introduce the conception of kernel density estimation into the histogram calculation. Our proposals is orthogonal to the published HEVC fast intra mode decision algorithms. Experimental results verified that, on average, the proposed methods reduced the encoding time by 25.21% in high efficiency mode, and 37.61% in low complexity mode, whereas the averaging BDPSNR losses are 0.0608dB and 0.0781dB, respectively. ¹.