A Segmentation-Based Chroma Intra Prediction Coding Scheme for H.264/AVC

In this paper, we propose a novel segmentation-based intra prediction coding scheme for low-bitrate video coding. Different coding schemes are separately designed for the luma and chroma components in our proposed method. The traditional block-based coding scheme is still used for the luma components, and the segmentation-based coding scheme is developed for the chroma components. The segmentation operation is used for the reconstructed luma components, which groups similar pixels together and produces a set of homogenous regions. Here, these local and homogenous regions are referred to superpixels. By utilizing the spatial correlation between the luma and chroma planes, we transfer the segmentation result of the luma components to the chroma components, which will not induce any side information in the chroma intra prediction coding. Instead of using the macroblock (MB) as the coding unit, the proposed method implements the chroma intra prediction in each superpixel, and the original pixels in each superpixel are employed to substitute the neighboring reconstructed samples in the prediction process. The experimental results show that the proposed method can achieve an average 0.20 dB and up to 0.63 dB coding gains in comparison to the directional intra prediction scheme for H.264/AVC low-bitrate video coding.