A fast intra mode decision technique

A new method for intra mode decision (IMD) of blocks in video encoding, with possible neighbor pixel selection comprising of both source and reconstructed pixels, is presented. This new technique of selecting neighbouring luma and chroma pixels for efficient intra mode prediction has been tested on WebM Project libvpx (vpx-vp8, VP8 standard) reference encoder [1]. This avoids the need of reconstruction of neighbour for block prediction, which eliminates the use of transformation, quantization, inverse-transformation and inverse-quantization blocks in IMD. The method has been studied with a set of seven video sequences with resolution varying from QCIF to full HD. The results show an average 48% reduction in encoder´s intra mode decision computation time with 0.0224 dB decrease in luma PSNR and 2.616% increase in bitrate. The proposed technique is useful in complexity reduction and increasing intra-prediction speed.