We consider the problem of video compression with free viewpoint interactivity. It is well believed that allowing the user to choose its view will incur some loss in terms of compression efficiency. Here we derive the...
详细信息
ISBN:
(纸本)9781479983407
We consider the problem of video compression with free viewpoint interactivity. It is well believed that allowing the user to choose its view will incur some loss in terms of compression efficiency. Here we derive the complete rate-storage region for universal lossless coding under the constraint of choosing the view at the receiver. This leads to a counterintuitive result: freely choosing its view at the receiver incurs a loss in terms of storage only and not in the transmission rate. The gain of the optimal scheme with respect to interactive schemes proposed so far is derived and a practical scheme that achieves this gain is proposed.
distributed video coding (DVC) is a videocoding paradigm that exploits the source statistics at the decoder based on the availability of the Side Information (SI). The SI can be seen as a noisy version of the source,...
详细信息
ISBN:
(纸本)9781479957521
distributed video coding (DVC) is a videocoding paradigm that exploits the source statistics at the decoder based on the availability of the Side Information (SI). The SI can be seen as a noisy version of the source, and the lower the noise the higher the RD performance of the decoder. The SI is usually generated by means of interpolation-based methods, which rely on the availability of a preceding and a following frame with respect to the to-be-decoded one. These methods lead to relatively high RD performance but also high delays. This work is focused on a low-delay DVC codec, relying only on preceding frames for the generation of the SI by means of Optical Flow (OF), which is also used in the refinement step of the SI for enhanced RD performance. Compared with a state-of-the-art extrapolation-based decoder the proposed solution achieves RD Bj0ntegaard gains up to 1.3 dB.
distributed video coding(DVC) is a new paradigm in video *** offers flexible partitioning of the complexity between the encoder and decoder,robustness to channel errors due to intrinsic joint source-channel coding,cod...
详细信息
distributed video coding(DVC) is a new paradigm in video *** offers flexible partitioning of the complexity between the encoder and decoder,robustness to channel errors due to intrinsic joint source-channel coding,codec independent scalability, and multi-view coding without communications between the *** makes it very interesting for a wide range of applications,in particular Multimedia ***-view DVC has recently received attention from the scientific *** the many challenging topics related to DVC there is the generation of the Side Information,which is estimated by the encoder of the data being *** paper presents a new method for spatial side information generation of uncalibrated video sensor network,which is based on Trifocal *** the spatial side information is fused with temporal intra-view side information to get better side *** results show that Trifocal Tensor-based spatial side information produces 1 to 2 dB improvement,while fusion-based side information produces 0.2 to 0.4 dB improvement in the PSNR of the rate-distortion *** performance is also improved.
This work tackles the problem of side information generation for the case of large-duration GOPs in distributed video coding. Based on a previously developed technique for side-information enhancement, we develop a ge...
详细信息
ISBN:
(纸本)9789898425720
This work tackles the problem of side information generation for the case of large-duration GOPs in distributed video coding. Based on a previously developed technique for side-information enhancement, we develop a genetic algorithm particularly designed for large GOPs, taking into account the GOP size, the additional bitrate incurred by encoding hash information, as well as the decoding complexity. The proposed algorithm makes use of different interpolation methods available in the literature in a fusion-based approach. A significant gain in the average PSNR that can reach 2 dB is observed with respect to the best performing interpolation technique, while the algorithm is run for no more than 18% of the total number of blocks in a given video sequence. On the other hand, while the encoding complexity is a main concern in distributed video coding, the proposed solution incurs no additional complexity at the encoder side in the case of hash-based Wyner-Ziv videocoding.
A key step in distributed video coding is the generation of the side information (SI) i.e. the estimation of the Wyner-Ziv frame (WZF). This step is also frequently called image interpolation. State-of-the-art techniq...
详细信息
ISBN:
(纸本)9781424442959
A key step in distributed video coding is the generation of the side information (SI) i.e. the estimation of the Wyner-Ziv frame (WZF). This step is also frequently called image interpolation. State-of-the-art techniques perform a motion estimation between adjacent key frames (KFs) and linear interpolation in order to assess object positions in the WZF, and then the SI is produced by motion compensating the KFs. However the uniform motion model underlying this approach is not always able to produce a satisfying estimation of the motion, which can result in a low SI quality. In this paper we propose a new method for the generation of SI, based on higher order motion interpolation. We use more than two KFs to estimate the position of the current WZF block, which allows us to correctly estimate more complex motion (such as, for example, uniform accelerated motion). We performed a number of tests for the fine tuning of the parameters of the method. Our experiments show that the new interpolation technique has a small computational cost increase with respect to state of the art, but provides remarkably better performance with up to 0.5 dB of PSNR improvement in SI quality. Moreover the proposed method performs consistently well for several GOP sizes.
Network multi-view stereoscopic TV remains an unfilled blank, because multi-view stereoscopic TV is characterized by high bit rate and low tolerance for bit error which are the restriction of the development of networ...
详细信息
ISBN:
(纸本)9781457714146
Network multi-view stereoscopic TV remains an unfilled blank, because multi-view stereoscopic TV is characterized by high bit rate and low tolerance for bit error which are the restriction of the development of network multi-view stereoscopic TV. This paper aims to solve the problem by distributed video coding (DVC) and GPU acceleration. distributed video coding is an effective approach of Wyner-Ziv videocoding for multi-view stereoscopic video encoded by LDPC. The distributed video coding based on channel coding offers flexible partitioning of the complexity between the encoder and the decoder to achieve a low complexity encoder for some applications, which are limited on calculation capability, memory capability and power consumption. Therefore, the DVC is suitable for wireless video capturing device, camera and so forth which the computation ability, memory size, power consumption are limited. The DVC decrease the complexity of encoding process, but increase the complexity of decoding process. To guarantee the fluent of the multi-view stereoscopic TV play, GPU is employed to accelerate the decoding process. The experiment result shows that joint decoding of eight views to generate the side information is more effective than conventional decoding of single view. And the CUDA could accelerate the decoding process efficiently.
In this paper, we present a novel technique for the suppression of the return channel in a multisensor distributed Wyner-Ziv videocoding system. The proposed technique relies on a cross-layer approach that takes into...
详细信息
In this paper, we present a novel technique for the suppression of the return channel in a multisensor distributed Wyner-Ziv videocoding system. The proposed technique relies on a cross-layer approach that takes into account the transmission channel conditions on one hand, and the content of the captured video scenes on the other, in order to allocate different transmission rates and dynamically vary the quantization parameter for each user. Simulation results show significant improvement in the average system performance compared to a traditional system where all users are assigned equal channel resources and a fixed number of quantization levels.
暂无评论