In this paper, we propose a scalable image compression scheme, including the base layer for feature representation and enhancement layer for texture representation. More specifically, the base layer is designed as the...
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ISBN:
(纸本)9781538662496
In this paper, we propose a scalable image compression scheme, including the base layer for feature representation and enhancement layer for texture representation. More specifically, the base layer is designed as the deep learning feature for analysis purpose, and it can also be converted to the fine structure with deep feature reconstruction. The enhancement layer, which serves to compress the residuals between the input image and the signals generated from the base layer, aims to faithfully reconstruct the input texture. The proposed scheme can feasibly inherit the advantages of both compress-then-analyze and analyze-then-compress schemes in surveillance applications. The performance of this framework is validated with facial images, and the conducted experiments provide useful evidences to show that the proposed framework can achieve better rate-accuracy and rate-distortion performance over conventional image compression schemes.
In this paper, a novel multiresolution algorithm for low bit-rate image compression is presented. High quality low bit-rate image compression is achieved by first decomposing the image into approximation and detail su...
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ISBN:
(纸本)0819427497
In this paper, a novel multiresolution algorithm for low bit-rate image compression is presented. High quality low bit-rate image compression is achieved by first decomposing the image into approximation and detail subimages with a shift-orthogonal multiresolution analysis. Then, at the coarsest resolution level, the coefficients of the transformation are encoded by an orthogonal matching pursuit algorithm with a wavelet packet dictionary. Our dictionary consists of convolutional splines of up to order two for the detail and approximation subbands. The intercorrelation between the various resolutions is then exploited by using the same bases from the dictionary to encode the coefficients of the finer resolution bands at the corresponding spatial locations. To further exploit the spatial correlation of the coefficients, the zero trees of wavelets (EZW) algorithm [I] was used to identify the potential zero trees. The coefficients of the presentation are then quantized and arithmetic encoded at each resolution, and packed into a scalable bit stream structure. Our new algorithm is highly bit-rate scalable, and performs better than the segmentation based matching pursuit [2,3] and EZW encoders at lower bit rates, based on subjective image quality and peak signal-to-noise ratio (PSNR).
When a video delivery system provides different representations of the same sequence, solutions can be found in simulcast coding, scalable coding, and transcoding. The major downside of transcoding is the additional c...
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ISBN:
(纸本)9781467325332;9781467325349
When a video delivery system provides different representations of the same sequence, solutions can be found in simulcast coding, scalable coding, and transcoding. The major downside of transcoding is the additional complexity needed to re-encode the video sequence in its new form. When one fidelity version of the video stream should be transmitted over the network, scalable coding is less efficient compared to single layer coding because of the layering overhead. Finally, simulcast encoding results in large storage requirements. In this paper, we propose an intermediate solution providing transcoding at a low complexity by the aid of control streams. We define a control stream as a regular video stream from which residual information is removed. With these control streams, the complexity of the encoding step in the transcoder can be reduced to decoder complexity. As a result of the removal of residual information, these control streams take up 62.8% less bitrate compared to simulcast coding for a test set based on High Efficiency Video coding (HEVC). Additionally, when compared to scalable coding, an efficient single layer video stream can be provided without the 16.6% bitrate increase caused by transmitting a layered bitstream.
This paper presents a comparative analysis of scalable stereoscopic video coding strategies for adaptive streaming. In particular, we compare scalable simulcast coding of both views using SVC with scalable coding of o...
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ISBN:
(纸本)9781424479948
This paper presents a comparative analysis of scalable stereoscopic video coding strategies for adaptive streaming. In particular, we compare scalable simulcast coding of both views using SVC with scalable coding of one view with SVC and non-scalable coding of the other view using H. 264/AVC, and benchmark them against non-scalable dependent coding of both views using the MVC. All of these coding options allow both symmetric and asymmetric coding of stereo videos. In addition, we propose a lightweight and periodic feedback mechanism for rate estimation and a strategy to adapt the total stereo source rate using SNR scalability option of SVC, while minimizing the loss rate of non-discardable packets. Experimental results show that dynamic rate scaling of only one view provides sufficient rate adaptation capability and better overall compression efficiency compared to scaling both of the views.
Light field imaging based on microlens arrays - also known as plenoptic, holoscopic and integral imaging - has recently risen up as feasible and prospective technology due to its ability to support functionalities not...
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ISBN:
(数字)9781510603349
ISBN:
(纸本)9781510603332;9781510603349
Light field imaging based on microlens arrays - also known as plenoptic, holoscopic and integral imaging - has recently risen up as feasible and prospective technology due to its ability to support functionalities not straightforwardly available in conventional imaging systems, such as: post-production refocusing and depth of field changing. However, to gradually reach the consumer market and to provide interoperability with current 2D and 3D representations, a display scalable coding solution is essential. In this context, this paper proposes an improved display scalable light field codec comprising a three-layer hierarchical coding architecture (previously proposed by the authors) that provides interoperability with 2D (Base Layer) and 3D stereo and multiview (First Layer) representations, while the Second Layer supports the complete light field content. For further improving the compression performance, novel exemplar-based inter-layer coding tools are proposed here for the Second Layer, namely: (i) an inter-layer reference picture construction relying on an exemplar-based optimization algorithm for texture synthesis, and (ii) a direct prediction mode based on exemplar texture samples from lower layers. Experimental results show that the proposed solution performs better than the tested benchmark solutions, including the authors' previous scalable codec.
This paper presents two novel methods to encode HD (High Definition) video at low bitrates (similar to5 Mbps) using the MPEG-2 Main Profile@Main Level standard (be compatible with current digital video devices;e.g., D...
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ISBN:
(纸本)0819448222
This paper presents two novel methods to encode HD (High Definition) video at low bitrates (similar to5 Mbps) using the MPEG-2 Main Profile@Main Level standard (be compatible with current digital video devices;e.g., DVD players, digital video recorders, etc.) with the embedded HD-relevant information (E-data) in the bitstream. Due to the low bitrate constraint, traditional coding based approaches (e.g., MPEG-2 layered coding or scalable coding) cannot satisfy this requirement. Therefore, we developed our system from the video-enhancement point of view. At first, the HD video is down converted to SD (Standard Definition). During the down-conversion, extra data (E-data) is saved. This E-data is used to re-create HD effects when the encoded SD is upconverted prior to the display. For HD re-creation, we developed a novel multilevel resolution-enhancement method that makes an upconverted image emulate the quality of the original HD picture. Further, we designed a visual-based fine detail injection method to add more details into the picture to achieve near HD quality. Based on several test video sequences, we conclude that our approaches have the potential to create HD visual effect on the upconverted SD video.
In conventional visual content representation, low-level visual features are usually extracted from the highest quality and resolutions of visual contents. When visual content is scalable coded and utilised, their bit...
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ISBN:
(纸本)9783540928911
In conventional visual content representation, low-level visual features are usually extracted from the highest quality and resolutions of visual contents. When visual content is scalable coded and utilised, their bit streams can be adapted at various nodes in multimedia usage chains to cater the variations in network bandwidths, display device resolutions and resources and usage preferences by just discarding insignificant resolution-quality layers. This can result in the existence of different version of the same content with dissimilar low-level visual features. Therefore, mapping of low level visual descriptors into content resolution-quality spaces is important in order to obtain low-level visual features that are robust to such content adaptations. A new scalable domain feature extraction using the compression modes and decisions is presented and its content based image retrieval performance is evaluated. The proposed scheme outperforms MPEG-7 visual descriptors in both the original image and scaled resolution-quality space domains.
This paper proposes a Key-Frame-Free (KFF) prediction method for the medium-grain scalable (MGS) coding of H. 264/SVC, in which the key pictures can be completely avoided to reduce the memory complexity and improve th...
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ISBN:
(纸本)9781457713033
This paper proposes a Key-Frame-Free (KFF) prediction method for the medium-grain scalable (MGS) coding of H. 264/SVC, in which the key pictures can be completely avoided to reduce the memory complexity and improve the coding efficiency. In our proposed method, the encoder employs a joint rate-distortion model to decide which quality layer is reconstructed and used for prediction of base quality macroblocks in the coarsest temporal layer, while the remaining macroblocks always predict and reconstruct from the highest quality layer. The proposed method requires no change to the H. 264/SVC standard and experimental results show that compared with the MGS key-picture control method the proposed scheme significantly improves the scalable coding efficiency from 0.8 to 1.5dB at higher bit rates while maintains similar drift error as MGS with key pictures at lower bit rates. Our proposed method can also coexist with SVC-to-AVC rewrite function which is conflict with the key picture of MGS
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 presents the design of a platform for distribution of multimedia content streams supported through innovative techniques, both in terms of media encoding and media distribution. The platform architecture ac...
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ISBN:
(纸本)9781424488650
This paper presents the design of a platform for distribution of multimedia content streams supported through innovative techniques, both in terms of media encoding and media distribution. The platform architecture accommodates the use of scalable media coding techniques, including both standard and state of the art research methods (wavelets, multiple description coding), combined with new transport and real-time streaming protocols deployed over peer-to-peer networks. Furthermore, discovery of media resources and selection of peer nodes takes into account social networking related information, as this is available in user communities over the Internet. The design of the platform is taking place in the context of the European FP7 project SARACEN.
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