JPEG 2000 a viable alternative to TIFF
Study shows JPEG 2000 image format is suitable for archiving and takes less disk space than TIFF
When it comes to preserving images in digital formats, the the more-compact JPEG 2000 image format can work just as well as Adobe's Tagged Image File Format (TIFF) format, according to a study recently published in D-Lib Magazine, a journal for digital preservation.
Paolo Buonora of Italy's archives and Franco Liberati of the Universit' degli Studi di Roma completed the study.
"Based on the results of our studies, we conclude that JPEG 2000 compression is a good current solution for our digital repositories," the researchers state. "Implementing wavelet compression and saving crucial information in extra file headers offers everyone a flexible and inexpensive strategy for maintaining image data into the future."
Wavelet compression is a technique built into the JPEG 2000 ISO Standard that can reduce the size of the image files without reducing the quality of the image itself'a technique called lossless compression. The former'and still most widely used version'of JPEG can reduce the size of the image, though it also reduces quality. This is called lossy compression.
The digital preservation community has long used TIFF format to encode images. Archivists have been slow to use JPEG 2000, fearing that encoding images can cause information loss. Use of TIFF, however, requires considerable disk space for large repositories.
"Typically, decision-makers must choose whether to keep terabytes of images in their original TIFF format or compress them. This can be a very difficult decision: to lose visual information though compression could be a waste of the money expended in the creation of the digital assets; however, by choosing to compress, the costs of storage will be reduced," the paper states.
JPEG 2000 seems to solve this dilemma.. The researchers noted that, even under intense visual scrutiny, JPEG 2000 images had no visual defects when compared with the original uncompressed images. Unlike JPEG, JPEG 2000 can save images in 48-bit color, like TIFF. Moreover, JPEG 2000 is more flexible than TIFF insofar is that it is a multi-resolution format.
"There is no reason for keeping three different formats of the image ' i.e., an original TIFF in high quality resolution, a medium resolution JPEG for Internet display, and a thumbnail for the catalogue webpage. The software ' in either a local or a remote client/server context ' will choose for us the resolution required," the paper states.
Italy is not alone in its endorsement of JPEG 2000 for archiving. In February, the British National Archives, referring to a study conducted by the Digital Preservation Coaltion, stated that the format is a "great stride forward for the archival community."
Maintained by the Corporation for National Research Initiatives, D-Lib is an electronic bimonthly journal dedicated to topics of digital library research and development.
Joab Jackson is the senior technology editor for Government Computer News.