Multiwavelet transform has important traits in image processing such as symmetric, orthogonal, smoothness, and short support. Theoretically speaking, multiwavelet should be a more satisfying tool for image coding. In ...
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ISBN:
(纸本)0819461148
Multiwavelet transform has important traits in image processing such as symmetric, orthogonal, smoothness, and short support. Theoretically speaking, multiwavelet should be a more satisfying tool for image coding. In this paper, we made deep research in the application of multiwavelets in scalable coding and proposed a new transmission-oriented image coding method, that is Fine Granularity scalable coding method based on CL multiwavelet transform. The experimental results show that the proposed coding method is effective. It is a valuable work on the application of multiwavelet transform in image coding.
In this paper, we propose an advanced fgs coding scheme based on MPEG-4 fgs technology. The proposed fgs enhancement-layer encoder takes as input the difference between the original DCT coefficient and the decision le...
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ISBN:
(纸本)9781424412730
In this paper, we propose an advanced fgs coding scheme based on MPEG-4 fgs technology. The proposed fgs enhancement-layer encoder takes as input the difference between the original DCT coefficient and the decision level of the quantizer, instead of the difference between the original DCT coefficient and its reconstruction level. Using this residual signal, the sign information of the enhancement-layer DCT coefficients can be the same as that of the base-layer ones at the same frequency index in DCT domain. Thus, overhead bits required for coding a lot of sign information of the enhancement-layer DCT coefficients in bit-plane coding can be removed from the generated bitstream. Moreover, the residue input signal to the enhancement layer shows a sharper distribution with less entropy for the DCT coefficients. Based on the sharper distribution, a new set of VLC tables are established for improved bit-plane coding. It is shown by simulations that the proposed fgs coding scheme provides better coding performance than the MPEG4 fgs coding.
A Robust Adaptive Video Encoder (RAVE) based on human visual model is proposed. The encoder combines the best features of Fine Granularity Scalable (fgs) coding, framedropping coding, video redundancy coding, and huma...
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A Robust Adaptive Video Encoder (RAVE) based on human visual model is proposed. The encoder combines the best features of Fine Granularity Scalable (fgs) coding, framedropping coding, video redundancy coding, and human visual model. According to packet loss and available bandwidth of the network, the encoder adjust the output bit rate by jointly adapting quantization step-size instructed by human visual model, rate shaping, and periodically inserting key frame. The proposed encoder is implemented based on MPEG-4 encoder and is compared with the case of a conventional fgs algorithm. It is shown that RAVE is a very efficient robust video encoder that provides improved visual quality for the receiver and consumes equal or less network resource. Results are confirmed by subjective tests and simulation tests.
This letter proposes an efficient wavelet-based Fine Granularity Scalable (fgs)coding scheme, where the base layer is encoded with a newly designed wavelet-based coder, and the enhancement layer is encoded with Progre...
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This letter proposes an efficient wavelet-based Fine Granularity Scalable (fgs)coding scheme, where the base layer is encoded with a newly designed wavelet-based coder, and the enhancement layer is encoded with Progressive Fine Granularity Scalable (Pfgs) *** algorithm involves multi-frame motion compensation, rate-distortion optimizing strategy with Lagrangian cost function and context-based adaptive arithmetic coding. In order to improve efficiency of the enhancement layer coding, an improved motion estimation scheme that uses both information from the base layer and the enhancement layer is also proposed in this letter. The wavelet-based coder significantly improves the coding efficiency of the base layer compared with MPEG-4 ASP (Advanced Simple Profile) and H.26L TML9. The Pfgs coding is a significant improvement over MPEG-4 fgs coding at the enhancement layer. Experiments show that single layer coding efficiency gain of the proposed scheme is about 2.0-3.0dB and 0.3-1.0dB higher than that of MPEG-4 ASP and H.26L TML9, respectively. The overall coding efficiency gain of the proposed scheme is about 4.0-5.0dB higher than that of MPEG-4 fgs.
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