Advanced Imaging


Advanced Imaging Magazine

Updated: July 8th, 2008 05:26 PM CDT



JPEG 2000's flexibility with respect to random access, code stream reordering and incremental decoding is highly exploitable in a networked environment. Part 9 of JPEG 2000 is written to define tools for supporting image and metadata delivery in the context.

The main component of JPEG 2000 Part 9 is a client-server protocol called JPIP (JPEG 2000 Interactive Protocol). It may be implemented on top of HTTP, but is designed with a view to other possible transports. To facilitate its deployment systems with varying degrees of complexity, JPIP handles several different formats for the image data returned by the server. These include ordinary image formats, such as complete JPEG or JPEG 2000 files, and two new types of incremental "stream" that uses JPEG 2000's "tiles" and "precincts" to take advantage of its scalability properties. JPIP also supports both stateless and stateful modes of operation, enabling sophisticated cache-modeling to eliminate the redundant transmission of data.

JPIP also provides selective access to the image metadata that may be contained within JPEG 2000 files. Although Part 9 is focused on the application of technology from Part 1, including the JP2 file format, it does support some file format extensions from Part 2. A mechanism has also been provided for selection from amongst multiple code streams in JPX (Part 2), MJ2 (Part 3), and JPM (Part 6) files. This could be applied to any file format containing images, not just to the JPEG 2000 family of file formats.

Part 9 also defines some new file format boxes for indexing JPEG 2000 files and code streams. The indexes are based on the same concepts as the JPIP stream types, and may be useful in server implementations of JPIP. They are also intended, however, to enable random access to JPEG 2000 files in the absence of JPIP. For example, the byte-range requests are built into an unmodified HTTP (version 1.1) server could be used for this purpose.


Subscribe to our RSS Feeds