Longshe Huo

H.264 video encryption scheme adaptive to DRM

In the paper, we propose an H.264 video content encryption scheme, which is based on the analysis of H.264 entropy coding, and has the features of irrelative to individual ciphers and adaptive to digital right management. Our scheme applies partial encryption of slice data to preserve the network-friendliness and compression performance of video coding. Compared with previous schemes such as selective encryption of fields, our scheme can efficiently overcome the problem of information leakage resulting from error concealment tools of video coding, greatly reduce the hardware design complexity of deencryption process, and still retain their virtues. Experiments show that, by encrypting only a little of the whole video data, our scheme can provide several different levels of content security involved in degraded picture quality from partial to no information leakage, and is suitable to be applied in the fields of multimedia storage and transmission

2D to 3D convertion based on edge defocus and segmentation

This paper presents a depth estimation method which converts two-dimensional images into three-dimensional data. Based on two-dimensional wavelet analysis of Lipschitz regularity for defocus estimation on edges, this method can effectively eliminate the horizontal stripes in the depth map resulted from traditional one-dimensional wavelet based approaches. Besides, we also propose several techniques such as edge enhancement, color-based segmentation, and depth optimization to obtain a more reliable and smoother depth map. The experimental results demonstrate the effectiveness of our proposed techniques.

A DRM Architecture for Manageable P2P Based IPTV System

With the improvement of network bandwidth, multimedia services based on streaming live media have gained much attention recently, among which IPTV has become a hot topic. After emergence of Peer-to-Peer (P2P) technology, P2P based IPTV systems are deployed widely. However, there exists a huge challenge, which is how to manage content. Digital rights management (DRM) is such a system that includes encryption and other technologies which can control the usage and redistribution of the digital contents. In this paper, we first review the related works in this area and analyze the DRM requirements. Then we propose a DRM architecture for a manageable P2P based IPTV system. In our architecture, we also present content encryption scheme and content authentication scheme.

Depth image segmentation for improved virtual view image quality in 3-DTV

A new 3-D data representation format consisting of monoscopic color video and its associated per-pixel depth information is a most promising technique applied in future three-dimensional television system. Despite many advantages of this representation, a large problem which is so-called disocclusion still exists when synthesizing one or more virtual views of a real-world scene by means of depth image based rendering technique. In this paper, we first give an interpretation to the occurrence of disocclusion from a mathematical view, and then analyze the reasons why smoothing depth image can have some effects on disocclusion and its several drawbacks. Finally, we propose a global processing method using depth image segmentation to solve the disocclusion. Analytical and experiment results show that our proposed method can improve the quality of virtual view images to a large extent, and no geometric distortion arises.

Depth Template Based 2D-to-3D Video Conversion and Coding System

A Depth Template based 2D-to-3D Video Conversion and Coding system (DTVCC) is proposed by this paper. In DTVCC, triangle meshes are exploited to describe depth template for scenes in 2D video, an interactive system is designed to generate reliable depth template, depth map can be automatically reconstructed based on the depth template and 2D video frame pixels information, and the generated 3D video is compressed just by coding the 2D video plus depth template. Experiment results show that not only high quality 3D video is generated, but also the bit rate of coding the converted 3D video is saved by 12%~38% with our proposed system of DTVCC.

A secure media streaming mechanism combining encryption, authentication, and transcoding

Technology advancements are allowing more and more new media applications and services to be delivered over the Internet. Many of these applications and services require flexibility in media distribution as well as security in protecting the confidentiality of media content and ensuring its authenticity. However, achieving flexibility and achieving security are conventionally conflicting with each other. This is mainly because that security is traditionally implemented in a media-unaware manner that naturally prevents flexible handling of the media content during its distribution. This paper shows that the two goals can be simultaneously accomplished by making an overall plan and taking into consideration all the factors: coding, encryption, packetization, authentication, and transcoding. It emphasizes sender authentication, which is a big security issue for media streaming, but somehow left unresolved. We propose a secure media streaming mechanism which supports media-aware encryption, sender authentication and secure transcoding. Multimedia Application Routing Server (MARS) is especially used as an intelligent mid-network proxy with the ability to perform tasks of sender authentication and secure transcoding. A prototype system for securely streaming AVS media using MARS demonstrates the performance, thus proves the practicality of the proposed secure media streaming mechanism.

Combining template matching and block motion compensation for video coding

A new motion compensation mode of TM_BMC is proposed by this paper to improve video coding efficiency. In TM_BMC, the inter-prediction efficiency is improved by combining the predictor of template matching and predictor of traditional block motion compensation, the coding cost for motion vector of traditional block motion compensation is reduced by utilizing motion vector derived by template matching as motion vector predictor. Experiment results on H.264 KTA platform show that average 7.07% and up to 11.26% bit-rate can be saved by locally adaptive motion compensation mode between the traditional motion compensation mode of BMC and the proposed mode of TM_BMC.

Symmetric segment-based stereo matching of motion blurred images with illumination variations

Most existing methods of stereo matching focus on dealing with clear image pairs. Consequently, there is a lack of approaches capable of handling degraded images captured under challenging real situations, e.g. motion blur is present and an image pair is in different illumination conditions. In this paper we propose a novel approach to handling these challenging situations by formulating the problem into a Maximum a Posteriori (MAP) estimation framework, and adopt a segment-based symmetric stereo matching method to infer a mask of disparity map which indicates whether a disparity is affected by motion blur and estimate the disparity value. The experimental results show that our stereo matching method is able to compute more accurate disparity maps of this type of degraded images.

A virtual view genetation method for free-viewpoint video system

Generating virtual views is one of the crucial problems for a free-viewpoint video system. In this paper, we solve the problem by using a method based on the technique of view morphing, and construct a multi-camera based experimental free-viewpoint video platform to validate its feasibility. This method requires no setting up of dense cameras, therefore the system is easy to be established and controlled in practice, and the mount of data for processing and transmitting can also be reduced. Experimental results show that the effect of this method can satisfy the requirement of view generation for the system.

FBSA: a self-adjustable multi-source data scheduling algorithm for P2P media streaming

Recently, there is great interest of using P2P network in multisource media streaming. In this paper, we present a self-adjustable scheduling algorithm for multi-source P2P media streaming, called feedback based scheduling algorithm (FBSA). FBSA is simple to implement, fully distributed, asynchronous, and can afford better quality of service. Furthermore, it can adjust itself automatically to adapt network heterogeneity, load variety, bandwidth fluctuation, and overlay dynamics. We have implemented FBSA, and tested it in a P2P live media streaming system: AVStreamer. Experimental results show that FBSA outperforms other conventional P2P data scheduling algorithms, especially in heterogeneous networks.