Wavelet-based Video Coding using Advanced Fractional Motion Estimation Technique

The purpose of this paper is to encode a color video by wavelet transformation. Therefore, we propose a new hybrid approach which combines a fractional motion estimation technique. Several studies were carried out to reduce the spatial and temporal redundancies, hence at the level of spatial video coding, we use a new approach based on sub-bands coding through a discrete wavelet transformation. This technique is based on the principle of the EZW algorithm of Shapiro. It proceeds by separating the encoding of the signs and the magnitudes of wavelet coefficients. Then, at the level of temporal compression, we propose a study of motion estimation with different accuracy based on image interpolation to improve the quality of predicted frame. Next, we present a representation reducing the size of the motion vector field and we compress it by two of entropic coding approaches namely Huffman coding and arithmetic coding. The proposed video codec was applied on a video sequence with different sizes (CIF and QCIF) and different dynamics. The obtained results, in terms of objective assessment (PSNR, the SSIM and VQM), were satisfactory compared with other video coding standards. We have also proposed a subjective evaluation and the results are compared to those obtained by H.264/AVC standard.