DigitalKoans

The Digital Preservation Coalition has published JPEG 2000—A Practical Digital Preservation Standard?.

Here's an excerpt from the "Executive Summary":

With JPEG 2000, an application can access and decode only as much of the compressed image as needed to perform the task at hand. This means a viewer, for example, can open a gigapixel image almost instantly by retrieving and decompressing a low resolution, display-sized image from the JPEG 2000 codestream.

JPEG 2000 also improves a user’s ability to interact with an image. The zoom, pan, and rotate operations that users increasingly expect in networked image systems are performed dynamically by accessing and decompressing just those parts of the JPEG 2000 codestream containing the compressed image data for the region of interest. The JPEG 2000 data can be either converted to JPEG and delivered for viewing with a standard image browser or delivered to a native JPEG 2000 viewer using the JPIP client-server protocol, developed to support the JPEG 2000 feature set.

Using a single JPEG 2000 master to satisfy user requests for dynamic viewing reduces storage costs and management overhead by eliminating the need to maintain multiple derivatives in a repository.

Beyond image access and distribution, JPEG 2000 is being used increasingly as a repository and archival image format. What is remarkable is that many repositories are storing “visually lossless” JPEG 2000 files: the compression is lossy and irreversible but the artefacts are not noticeable and do not interfere with the performance of applications. Compared to uncompressed TIFF, visually lossless JPEG 2000 compression can reduce the amount of storage by an order of magnitude or more.

This entry was posted on Thursday, February 21st, 2008 at 9:45 am and is filed under Digital Media, Digital Preservation, Standards. Comments closed here. Read and add comments at http://www.digital-scholarship.org/digitalkoans/.