Best practices for the storage of digital images in the library and archives communities use the TIFF and JPEG file formats. The older JPEG format reduces the amount of space required to store images through a form of compression that sacrifices image detail. The TIFF format provides options for compression that do not affect image fidelity, but few have gained wide acceptance and those that have are based on patented algorithms. By comparison, the compression scheme used by JPEG 2000 is free of license and royalty restrictions and provides for âlosslessâ compression of image data.
An âopen standardâ is one that is free for anyone to read, understand, and implement with no royalties or fees. TIFF is an open standard, although the optional compression algorithm it uses is not. Another file format used extensively in the map and satellite photography fields, SID, offers compression but is also patented technology. The JPEG 2000 standard, as with all open standards, encourages multiple products for processing these files to be created in a competitive marketplace with assurance that adherence to the standard will result in interoperability. The open nature of the standard also ensures that software can be written to process the files long after a commercial advantage has been realized.