SID file format is used by MrSID software application. This file type is used to store the georeferenced raster graphics.

The main purpose of creating this file type was to store a large image file which was usually take aerially or through satellite and view them quickly. The visual data stored in SID file format is compressed when the file is created and when the user opens the file the file is able to show all of its components without decompressing the complete file. Due to its capability of storing large amount of detail for a single image SID file format is also used in some cases to store fingerprints.