Polytope Faces Pursuit is a greedy algorithm that performs Basis Pursuit with similar order complexity to Orthogonal Matching Pursuit. The algorithm adds one basis vector at a time and adopts a path-following approach based on the geometry of the polar polytope associated with the dual Linear Program. Its initial implementation uses the method of Cholesky factorization to update the solution vector at each step, which can be computationally expensive for solving large scale problems as it requires the succesive storage of large matrices. In this paper, we present a different approach using directional updates to estimate the solution vector at each time. The proposed method uses the gradient descent method, reducing the memory requirements and computational complexity. We demonstrate the application of this Gradient Polytope Faces Pursuit algorithm to a source separation problem.

A framework is presented which addresses the issues related to the real-time implementation of synchronized video and audio time-scale and pitch-scale modification algorithms. It allows for seamless real-time transition between continually varying, independent time-scale and pitch-scale parameters arising as a result of manual or automatic intervention. We illuminate the problems which arise in a real-time context as well as provide novel solutions to prevent artifacts, minimize latency, and improve synchronization. The time and pitch scaling approach is based on a modified phase vocoder with optional phase locking and an integrated transient detector which enables high-quality transient preservation in real-time. A novel method for audio/visual synchronization was implemented in order to ensure no perceptible latency between audio and video while real-time time scaling and pitch shifting is applied. Evaluation results are reported which demonstrate both high audio quality and minimal synchronization error.

Many digital sound archives still suffer from tremendous problems concerning access. Materials are often in different formats, with related media in separate collections, and with non-standard, specialist, incomplete or even erroneous metadata. Thus, the end user is unable to discover the full value of the archived material. EASAIER addresses these issues with the development of an innovative remote access system which extends beyond standard content management and retrieval systems. The EASAIER system has been designed with sound archives, libraries, museums, broadcast archives, and music schools in mind. However, the tools may be used by anyone interested in accessing archived material; amateur or professional, regardless of the material involved. Furthermore, it enriches the access experience enabling the user to experiment with the materials in exciting new ways. The system features; enhanced cross media retrieval functionality, multi-media synchronisation, audio and video processing, analysis and visualisation tools, all combined within in a single user configurable interface.

This paper describes scheme for protection of watermarking channel and its capacity enhancement using state-of-the-art error correction technique - turbo coding. Duo-binary codes were used for protection since they are perform better then classical turbo coders in terms of better convergence for iterative decoding, a large minimum distance and also computational expensiveness. A spread spectrum watermarking technique is used to insert watermark. Proposed pseudo-random watermarking bits spreading, amplitude adjustment in DCT domain based on block classification and bit-rate preserving increased signal to noise ratio of the watermarking channel. However, it was essential to introduce an error correction technique in order to achieve high capacity and robustness. In addition, experimental results on robustness to transcoding are presented

Interactive and seamless access to video content is facilitated by technology that is able to annotate and retrieve media data efficiently and automatically with the minimal human interventions. Media should be accessible by intended users quickly and independent of the database size, regardless of the homogeneous or heterogeneous nature of the delivery channels or the user computing platform. These requirements are driving research and development efforts in the European project BUSMAN; in which a system for efficient annotation, seamless delivery of and access to video components across heterogeneous channels is being developed. The BUSMAN system architecture is based on the needs and expectations of two types of users: content providers and end users. In this paper an overview of the BUSMAN system is presented and its main functionalities are described.