MrSID (Multi-resolution Seamless Image Database) is an image compressor, viewer, and file format for extremely large raster graphics images. MrSID, created by LizardTech, works by putting together hundreds of small image tiles into one large seamless image that can be compressed and decompressed with little or no degradation.
One problem previously associated with raster images was the long amount of time it took to open very large files. The creators of MrSID overcame that problem by giving the user the ability to decompress just the portion of the image they wanted to view. The user can move from one part of the image to another quickly without having to wait for the entire image to decompress.
Another problem associated with massive raster images was the large amount of storage space they required. MrSID uses a patented "wavelet" technology first developed at the National Research Laboratories at Los Alamos to achieve a compression ratio of 20:1 for greyscale images and 50:1 for full color images. Now, a satellite photo from space that once required the storage space of forty CD-ROMs, could be compressed with MrSID and stored on one CD-ROM.
The wavelet technology used by MrSID relies on advanced mathematical algorithms both to compress an image and build the viewer. Since the image remains geometrically accurate after compression, it can be geo-referenced before compression or overlaid with other referencing data. Because MrSID (.sid) files are a binary MIME type, they can be served over the Internet. MrSID is used in photography, mapping/GIS, document management, medical imaging, and games.