SID (Seamless Image Database) is a wavelet-based geospatial imagery format developed by LizardTech. It is primarily used for storing and distributing large raster images, particularly aerial and satellite imagery, maps, and other geospatial data. SID files are known for their efficient compression, which allows for relatively small file sizes without significant loss of image quality. This makes them ideal for online distribution and use in GIS (Geographic Information System) applications. The wavelet compression technique enables progressive decoding, meaning that lower-resolution versions of the image can be displayed quickly, with higher-resolution details loading as needed. This is particularly useful for viewing large images over networks with limited bandwidth. SID files can contain multiple layers of image data and support georeferencing information, allowing them to be accurately positioned within a geographic coordinate system. While LizardTech was acquired by Celartem, and subsequently by ERDAS, the SID format remains a widely used format in the geospatial industry.