Video-objectcoding is one of the most important functionalities proposed by MPEG-4. In this paper, we propose a new wavelet method to encode the texture of an arbitrarily shaped object, both for the still and for the...
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Video-objectcoding is one of the most important functionalities proposed by MPEG-4. In this paper, we propose a new wavelet method to encode the texture of an arbitrarily shaped object, both for the still and for the video object. The method uses the shape adaptive wavelet transform (SA-DWT) in MPEG-4 still objectcoding, but with a computationally more efficient lifting implementation. The transformed object coefficients are then quantized and entropy encoded with a partial bit-plane embedded coder, which greatly improves the coding efficiency. We denote the coding algorithm as the video object wavelet (VOW) coder. Experimental results show that VOW significantly outperforms MPEG-4 in still-objectcoding, and achieves a comparable performance in video objectcoding in terms of PSNR. Moreover, the VOW decoded object looks better subjectively, with less annoying blocking artifacts than that of MPEG-4.
MPEG-4, with its superior compression, interactivity and universal access, is the most promising future standard. MPEG-4 relies on a content-based representation so it can provide new functionalities such as content-b...
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ISBN:
(纸本)0819447145
MPEG-4, with its superior compression, interactivity and universal access, is the most promising future standard. MPEG-4 relies on a content-based representation so it can provide new functionalities such as content-based interactivity and scalability. Content-based coding, which encodes the objects within a picture, is one of the most important functionalities proposed by MPEG-4, and it has attracted considerable attention. Moreover, encoding the texture of an arbitrarily shaped object is an important part of object-based coding. Therefore, many researchers have being trying their best to solve this problem, and they proposed various methods to encode the texture of an arbitrarily shaped object. In this paper, we summarize several methods of arbitrarily shaped objectcoding including SA-DCT (shape Adapted-DCT), EA-DCT (Expanded arbitrary-shaped DCT), Mean Replacement Padding and Low Pass Extrapolation Method (LPE). We also propose two new padding method of arbitrarily shaped objectcoding. Experimental results showed that the proposed methods have almost the same effect as LPE method, which MPEG-4 has adopted, so that it can improve the coding efficiency of DCT.
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