In the scalable video coder MC-EZBC, the motion-vector (MV) bitstream was not scalable in bitrate or resolution. In this short paper, we enhance MC-EZBC with a new scalable MV coder based on context adaptive binary ar...
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In the scalable video coder MC-EZBC, the motion-vector (MV) bitstream was not scalable in bitrate or resolution. In this short paper, we enhance MC-EZBC with a new scalable MV coder based on context adaptive binary arithmetic coding. Alphabet general partition of MV symbols is proposed to achieve accuracy or quality scalability of MVs. A selective layered structure is used to reduce the number of MVs transmitted when appropriate, mainly needed for resolution scalability. With these two additions, we have a layered temporal, SNR, and resolution scalability for the MV bitstream. Experimentally, we find that this gives significant visual and objective improvement for low bitrates and/or resolutions with only very slight PSNR loss and unnoticeable visual loss at high bitrates.
Modem video coding applications require transmission of video data over variable-bandwidth channels to a variety of terminals with different screen resolutions and available computational power. scalable video coding ...
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ISBN:
(纸本)0819454966
Modem video coding applications require transmission of video data over variable-bandwidth channels to a variety of terminals with different screen resolutions and available computational power. scalable video coding is needed to optimally support these applications. Recently proposed wavelet-based video codecs employing spatial domain motion compensated temporal filtering (SDMCTF) provide quality, resolution and frame-rate scalability while delivering compression performance comparable to that of the state-of-the-art non-scalable H.264-codec. These codecs require scalablecoding of the motionvectors in order to support a large range of bit-rates with optimal compression efficiency. scalable motion vector coding algorithms based on the integer wavelet transform followed by embedded coding of the wavelet coefficients were recently proposed. In this paper, a new and fundamentally different scalablemotionvector codec (MVC) using median-based motionvector prediction is proposed. Extensive experimental results demonstrate that the proposed MVC systematically outperforms the wavelet-based state-of-the-art solutions. To be able to take advantage of the proposed scalable MVC, a rate allocation mechanism capable of optimally dividing the available rate among texture and motion information is required. Two rate allocation strategies are proposed and compared. The proposed MVC and rate allocation schemes are incorporated into an SDMCTF-based video codec and the benefits of scalable motion vector coding are experimentally demonstrated.
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