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Abstract-The seamless access to rich multimedia content on any device and over any network, usually known as Universal Multimedia Access, requires interoperable description tools and adaptation techniques to be developed. To address the latter issue, MPEG-21 Digital Item Adaptation (DIA) introduces the Bitstream Syntax Description (BSD) framework, which provides tools for adapting multimedia content in a generic (i.e., coding format independent) way. The basic idea is to use the eXtensible Markup Language (XML) to describe the high-level structure of a binary media bitstream, to transform its description [e.g., by means of eXtensible Stylesheet Language Transformations (XSLT)], and to construct the adapted media bitstream from the transformed description. This paper presents how this basic BSD framework, initially developed for nonstreamed content and suffering from inherent limitations and high memory consumption of XML-related technologies such as XSLT, can be advanced and efficiently implemented in a streaming environment and on resource-constrained devices. Two different attempts to solve the inherent problems are described. The first approach proposes an architecture based on the streamed processing of Simple Application Programming Interface for XML (SAX) events and adopts Streaming Transformations for XML (STX) as an alternative to XSLT, whereas the second approach breaks a BSD up into well-formed fragments called process units that can be processed individually by a standard XSLT processor. The current status of our work, as well as directions for future research, are given.

Abstract. Nowadays, conventional X-ray radiographs are still the images of choice for evaluating spinal deformaties such as scoliosis. However, digital translation reconstruction gives easy access to high quality, digital overview images of the entire spine. This work aims at improving the description of the scoliotic deformity by developing semi-automated tools to assist the extraction of anatomical landmarks (on vertebral bodies and pedicles) and the calculation of deformity quantifying parameters. These tools are currently validated in a clinical setting.

In previous works, a generic framework for multimedia content adaptation has been introduced, where XML is used to describe the high-level structure of a bitstream and the resulting description is first transformed by an XSLT style sheet, and then processed to generate an adapted bitstream. In order to provide full interoperability, a new language named Bitstream Syntax Description Language (BSDL) is built on top of W3C XML Schema for the purpose of this generation process. A schema designed in this language and specific to a given coding format allows a generic processor to parse a description and generate the corresponding adapted bitstream. This paper describes an extension of BSDL to provide the new functionality corresponding to the reverse operation, i.e. allowing a generic software module to parse a bitstream conforming to a given coding format described by a schema, and generate the corresponding description. For this, BSDL introduces a number of language mechanisms on top of XML Schema. This paper details these language extensions and reviews the strengths and limits of this approach.