This paper proposes a video streaming system optimizing resource utilization when the media server only disposes of long term feedbacks from the client. Based on a partial knowledge of the network, we developed a sche...
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ISBN:
(纸本)9781424456536
This paper proposes a video streaming system optimizing resource utilization when the media server only disposes of long term feedbacks from the client. Based on a partial knowledge of the network, we developed a scheduling algorithm that exploits the scalable video coding (SVC) properties to estimate packets importance and that takes into account packet delay dependencies to better anticipate congestion situations. Compared to more conventional streaming systems, experimental results show that our approach allows to better face network condition degradation like bandwidth reduction or packet error rate increase.
This paper offers an introduction to a new paradigm for resampling filters (both downsampling and upsampling filters), with an emphasis on a new performance metric - the roundtrip (down, up) high resolution reconstruc...
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ISBN:
(纸本)9780819477330
This paper offers an introduction to a new paradigm for resampling filters (both downsampling and upsampling filters), with an emphasis on a new performance metric - the roundtrip (down, up) high resolution reconstruction quality. Existing philosophy in the construction of resampling filters is to design them individually to minimize aliasing artifacts caused by the resampling process. The net result of a roundtrip high-to-low-to-high resolution reconstruction while using such filters certainly minimizes aliasing, but misses an important opportunity -- to capture more information in the lower resolution signal which, though aliased, can contribute to higher quality reconstruction when paired with an appropriately designed upsampling filter. While the criterion of high-resolution reconstruction quality is not new, alias control has been so heavily emphasized to date that surprisingly little work has been done in the literature to specifically address this important metric. We provide a setting for this new theory in the context of Laplace Pyramids, and develop specific resampling filters that outperform previous state-of-the-art filters in our context. Our filters were first developed and proposed in the course of the ISO/ITU Joint Video Team's scalable Video coding (SVC) standardization project.
The canonical representation of speech constitutes a perfect reconstruction (PR) analysis-synthesis system. Its parameters are the autoregressive (AR) model coefficients, the pitch period and the voiced and unvoiced c...
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ISBN:
(纸本)9781424432974
The canonical representation of speech constitutes a perfect reconstruction (PR) analysis-synthesis system. Its parameters are the autoregressive (AR) model coefficients, the pitch period and the voiced and unvoiced components of the excitation represented as transform coefficients. Each set of parameters may be operated on independently. A time-frequency unvoiced excitation (TFUNEX) model is proposed that has high time resolution and selective frequency resolution. Improved time-frequency fit is obtained by using for antialiasing cancellation the clustering of pitch-synchronous transform tracks defined in the modulation transform domain. The TFUNEX model delivers high-quality speech while compressing the unvoiced excitation representation about 13 times over its raw transform coefficient representation for wideband speech.
A multiview stereo video FGS (Fine Granular Scalability) scalable scheme is presented in this paper. The similarity among adjacent views is fully utilized, A tradeoff scheme is presented in order to adapt to different...
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ISBN:
(纸本)9781424443178
A multiview stereo video FGS (Fine Granular Scalability) scalable scheme is presented in this paper. The similarity among adjacent views is fully utilized, A tradeoff scheme is presented in order to adapt to different demands of Quality First (QF) and View First (VF) of the decoder. The scheme is composed of three cases: 1, P, B frame. The middle view is encoded as the basic layer, while the other views are predicted from the partly retrieved FGS enhancement layers of adjacent views. The FGS enhancement layer of the current view is generated based on that. Experimental results show that the presented scheme is of more flexible and extensive scalable characteristic, which could better adapt different demands on view image quality and stereo immersion of different users.
This paper proposes a novel framework for the compression and transmission of the auto-stereo video. Based on the video-plus-depth data representation, this framework provides high adaptability, reliability and flexib...
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ISBN:
(纸本)9781424442461
This paper proposes a novel framework for the compression and transmission of the auto-stereo video. Based on the video-plus-depth data representation, this framework provides high adaptability, reliability and flexibility for the stereo display. Besides, it also permits the consumers to be interactive with the perception of the stereo video. The proposed compression approach for the video-plus-depth data representation utilizes the characteristics of the human vision system and reduces data amount effectively. The transmission approach, in combination with the data hiding technology and the effective coding algorithm, performs well in our framework. Both the early experiments of our research group and the theory analysis of the coding algorithm can guarantee the performance of the whole framework for the compression and transmission of the auto-stereo video. Technical challenges are identified in the end.
A simple lossy-to-lossless bit-plane coding of still images is presented to integrate several functionality extensions including selective the partitioning, progressive transmission, ROI transmission, accuracy scalabi...
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ISBN:
(纸本)9781424445936
A simple lossy-to-lossless bit-plane coding of still images is presented to integrate several functionality extensions including selective the partitioning, progressive transmission, ROI transmission, accuracy scalability, and others. The mean squared error between the original image and a decoded image at any progression level is known prior to encoding/decoding. The proposed bit-plane codec is competitive with JPEG-LS and JPEG 2000 in the lossless compression of 8-bit grayscale and 24-bit color images. The codec outperforms the existing standards in 8-bit color-quantized image compression.
This paper presents a method of scalable lossless image compression by means of lossy coding. A progressive decoding capability and a full decoding for the lossless rendition are equipped with the losslessly encoded b...
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This paper presents a method of scalable lossless image compression by means of lossy coding. A progressive decoding capability and a full decoding for the lossless rendition are equipped with the losslessly encoded bit stream. Embedded coding is applied to large-amplitude coefficients in a wavelet transform domain. The other wavelet coefficients are encoded by a context-based entropy coding. The proposed method slightly outperforms JPEG-LS in lossless compression. Its rate-distortion performance with respect to progressive decoding is close to that of JPEG2000. The spatial scalability with respect to resolution is also available.
Motion-compensated fine-granularity scalability (MC-FGS) with leaky prediction has been shown to provide an efficient tradeoff between compression gain and error resilience, facilitating the transmission of video over...
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Motion-compensated fine-granularity scalability (MC-FGS) with leaky prediction has been shown to provide an efficient tradeoff between compression gain and error resilience, facilitating the transmission of video over dynamic channel conditions. In this paper, we propose an n-channel symmetric motion-compensated multiple description (MD) coding and transmission scheme for the delivery of scalable video over orthogonal frequency division multiplexed systems, utilizing the concepts of partial and leaky predictions. We investigate the proposed MD coding and transmission scheme using a cross-layer design perspective. In particular, we construct the symmetric motion-compensated MD codes based on the diversity order of the channel, defined as the ratio of the overall bandwidth of the system to the coherence bandwidth of the channel. We show that knowing the diversity order of a physical channel can assist an MC-FGS video coder in selecting the motion-compensation prediction point, as well as on the use of leaky prediction. More importantly, we illustrate how the side information can reduce the drift management problem associated with the construction of symmetric motion-compensated MD codes. We provide results based on both an information-theoretic approach and simulations.
This paper proposes a novel framework for the compression and transmission of the auto-stereo video. Based on the video-plus-depth data representation, this framework provides high adaptability, reliability and flexib...
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This paper proposes a novel framework for the compression and transmission of the auto-stereo video. Based on the video-plus-depth data representation, this framework provides high adaptability, reliability and flexibility for the stereo display. Besides, it also permits the consumers to be interactive with the perception of the stereo video. The proposed compression approach for the video-plus-depth data representation utilizes the characteristics of the human vision system and reduces data amount effectively. The transmission approach, in combination with the data hiding technology and the effective coding algorithm, performs well in our framework. Both the early experiments of our research group and the theory analysis of the coding algorithm can guarantee the performance of the whole framework for the compression and transmission of the auto-stereo video. Technical challenges are identified in the end.
We propose a wavelet-based codec for the static depth-image-based representation, which allows viewers to freely choose the viewpoint. The proposed codec jointly estimates and encodes the unknown depth map from multip...
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We propose a wavelet-based codec for the static depth-image-based representation, which allows viewers to freely choose the viewpoint. The proposed codec jointly estimates and encodes the unknown depth map from multiple views using a novel rate-distortion (RD) optimization scheme. The rate constraint reduces the ambiguity of depth estimation by favoring piece-wise-smooth depth maps. The optimization is efficiently solved by a novel dynamic programming along trees of integer wavelet coefficients. The codec encodes the image and the depth map jointly to decrease their redundancy and to provide a RD-optimized bitrate allocation between the two. The codec also offers scalability both in resolution and in quality. Experiments on real data show the effectiveness of the proposed codec.
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