Arbitrarily shaped video object coding by wavelet

Video object coding is one of the most important functionalities proposed by MPEG4. In this paper, we propose a new wavelet method to encode the texture of an arbitrarily shaped object, both for the still and video object. The method uses the shape adaptive wavelet transform (SA-DWT) in MPEG4 still object coding, but with a computationally more efficient lifting implementation. The transformed object coefficients are then quantized and entropy encoded with a partial bitplane embedded coder, which greatly improves the coding efficiency. We denote the coding algorithm as a video object wavelet (VOW) coder. Experimental results show that VOW significantly outperforms MPEG4 in still object coding, and achieves a comparable performance in video object coding in terms of PSNR. Moreover, the VOW decoded object looks better subjectively, with less annoying blocking artifacts than that of MPEG4