Zerotree-based stereoscopic video CODEC

Due to the provision of a more natural representation of a scene in the form of left and right eye views, a stereoscopic imaging system provides a more effective method for image/video display. Unfortunately the vast amount of information that must be transmitted/stored to represent a stereo image pair/video sequence, has so far hindered its use in commercial applications. However, by properly exploiting the spatial, temporal and binocular redundancy, a stereo image pair or a sequence could be compressed and transmitted through a single monocular channel’s bandwidth without unduly sacrificing the perceived stereoscopic image quality. We propose a timely and novel framework to transmit stereoscopic data efficiently. We propose a timely and novel framework to transmit stereoscopic data efficiently. We present a new technique for coding stereo video sequences based on discrete wavelet transform DWT technology. The proposed technique particularly exploits zerotree entropy ZTE coding that makes use of the wavelet block concept to achieve low bit rate stereo video coding. One of the two image streams, namely, the main stream, is independently coded by a zerotree video CODEC, while the second stream, namely, the auxiliary stream, is predicted based on disparity compensation. A zerotree video CODEC subsequently codes the residual stream. We compare the performance of the proposed CODEC with a discrete cosine transform DCT -based, modified MPEG-2 stereo video CODEC. We show that the proposed CODEC outperforms the benchmark CODEC in coding both main and auxiliary streams

Compressed-domain shot boundary detection for H.264/AVC using intra partitioning maps

In this paper, a novel technique for shot boundary detection operating on H.264/AVC-compressed sequences is presented. Due to new and improved coding tools in H.264/AVC, the characteristics of the obtained sequences differ from former video coding standards. Although several algorithms working on this new standard are already proposed, the presence of IDR frames can still lead to a low accuracy for abrupt transitions. To solve this issue, we present the motion-compensated intra partitioning map which relies on the intra partitioning modes and the motion vectors present in the compressed video stream. Experimental results show that this motion-compensated map achieves a high accuracy and exceeds related work

A new reduced reference objective quality metric for stereoscopic video

A new reduced reference (RR) objective quality metric for stereoscopic video is proposed that incorporates spatial neighbouring information. The contrast measures from grey level co-occurrence matrices (GLCM) for both colour and depth are the main parts of spatial information. Side information are extracted from edge information of original video and sent through an auxiliary channel. The other important factor in the proposed metric is the unequal weight of colour and depth views, which can maximise the performance of the proposed metric for some specific values. Performance of the proposed metric is validated through series of subjective tests to show how it correlates subjective quality scores. The average correlation of the proposed metric and subjective quality scores is 0.82 when colour to depth importance ratio is near 4. © 2012 IEEE

User experience in immersive TV - a research agenda

This paper explores existing theories and models for investigating user experience in the context of Distributed Interactive Multimedia Environments (DIME) in the framework of an immersive TV show developed within ACTION-TV project. A descriptive research framework is suggested, which integrates Quality of Service (QoS), Quality of Experience (QoE) and User Experience (UX) to support user-centered design and development in DIME. A study, which was conducted during the project and which addresses different aspects of the framework, is presented

Display-dependent preprocessing of depth maps based on just-noticeable depth difference modeling

This paper addresses the sensitivity of human vision to spatial depth variations in a 3-D video scene, seen on a stereoscopic display, based on an experimental derivation of a just noticeable depth difference (JNDD) model. The main target is to exploit the depth perception sensitivity of humans in suppressing the unnecessary spatial depth details, hence reducing the transmission overhead allocated to depth maps. Based on the JNDD model derived, depth map sequences are preprocessed to suppress the depth details that are not perceivable by the viewers and to minimize the rendering artefacts that arise due to optical noise, where the optical noise is triggered by the inaccuracies in the depth estimation process. Theoretical and experimental evidences are provided to illustrate that the proposed depth adaptive preprocessing filter does not alter the 3-D visual quality or the view synthesis quality for free-viewpoint video applications. Experimental results suggest that the bit rate for depth map coding can be reduced up to 78% for the depth maps captured with depth-range cameras and up to 24% for the depth maps estimated with computer vision algorithms, without affecting the 3-D visual quality or the arbitrary view synthesis quality

Utilisation of motion similarity in colour-plus-depth 3D video for improved error resiliency

Robust 3D stereoscopic video transmission over error-prone networks has been a challenging task. Sustainability of the perceived 3D video quality is essential in case of channel losses. Colour-plus-Depth format on the other hand, has been popular for representing the stereoscopic video, due to its flexibility, low encoding cost compared to left-right stereoscopic video and backwards compatibility. Traditionally, the similarities existing between the colour and the depth map videos are not exploited during 3D video coding. In other words, both components are encoded separately. The similarities include the similarity in motion, image gradients and segments. In this work, we propose to exploit the similarity in the motion characteristics of the colour and the depth map videos by computing only a set of motion vectors and duplicating it for the sake of error resiliency. As the previous research has shown that the stereoscopic video quality is primarily affected by the colour texture quality, especially the motion vectors are computed for the colour video component and the corresponding vectors are used to encode the depth maps. Since the colour motion vectors are protected by duplication, the results have shown that both the colour video quality and the overall stereoscopic video quality are maintained in error-prone conditions at the expense of slight loss in depth map video coding performance. Furthermore, total encoding time is reduced by not calculating the motion vectors for depth map