{"id":"image-x-mrsid-image","mimeType":"image/x-mrsid-image","name":"Multi-resolution Seamless Image Database","shortName":"MrSID","category":"Geospatial \u0026 GIS Graphics","extensions":[".sid"],"description":"The image/x-mrsid-image MIME type represents the MrSID (Multi-resolution Seamless Image Database) format. Originally developed by researchers at the Los Alamos National Laboratory (LANL) and later commercialized by LizardTech (now Extensis), MrSID is a highly specialized proprietary format utilized extensively in Geographic Information Systems (GIS). It employs discrete wavelet transform (DWT) compression to shrink massive raster datasets—such as multi-gigabyte satellite imagery or aerial orthophotography—by up to 95% without significant visual degradation. Its key feature is allowing users to seamlessly pan and zoom through colossal images instantly, as the software only decompresses the specific resolution level and physical bounding box currently being viewed.","seo":{"title":"image/x-mrsid-image MIME Type | Developer Reference for MrSID","description":"Complete reference for the image/x-mrsid-image MIME type: MrSID GIS format, Extensis/LizardTech history, wavelet compression, and geospatial imagery.","faqs":[{"question":"What is a MrSID (.sid) file?","answer":"A MrSID (Multi-resolution Seamless Image Database) file is a highly compressed raster image format used primarily in GIS (Geographic Information Systems) to store massive satellite maps and aerial photography."},{"question":"How do I open a .sid file?","answer":"Standard image viewers cannot open MrSID files. You need dedicated GIS software such as QGIS, Esri ArcGIS, or the free Extensis GeoViewer. You may also need the accompanying '.sdw' (world file) to properly geolocate the image on a map."},{"question":"What is the difference between MrSID and GeoTIFF?","answer":"GeoTIFF is an open standard that is widely supported but can result in massive file sizes for high-resolution maps. MrSID is a proprietary format that uses wavelet compression to drastically reduce file sizes while allowing instantaneous zooming and panning without loading the entire image into RAM."}]},"index":{"compression":["Proprietary Wavelet (Lossy)","Proprietary Wavelet (Lossless)"],"browserSupport":{"score":1,"label":"None"},"commonUses":["Geographic Information Systems (GIS)","Satellite Imagery Archival","Aerial Orthophotography Mosaics"]},"technical":{"magicBytes":{"hex":"6D 73 69 64","ascii":"msid"},"container":"Proprietary MrSID Container","compressionAlgorithm":["Discrete Wavelet Transform (DWT)"],"colorDepth":["8-bit (Grayscale)","24-bit (RGB)","Multi-spectral (Multiple bands)"],"transparency":true,"animation":false,"metadata":{"exif":true,"xmp":true,"iccProfile":true},"alphaChannel":true,"progressiveLoading":true,"hdrSupport":false},"history":{"developer":"Los Alamos National Laboratory / LizardTech (Extensis)","released":"1992","specification":"Proprietary (Extensis MrSID DSDK required)"},"browserSupport":{"chrome":false,"chromeVersion":"None","firefox":false,"firefoxVersion":"None","safari":false,"safariVersion":"None","edge":false,"edgeVersion":"None","internetExplorer":false},"softwareSupport":[{"name":"QGIS","logo":""},{"name":"Esri ArcGIS","logo":""},{"name":"Extensis GeoViewer","logo":""},{"name":"GDAL (Geospatial Data Abstraction Library)","logo":""}],"conversion":{"convertTo":["tiff","jp2","png"],"convertFrom":["tiff","ecw","jp2"]},"developer":{"httpHeaders":[{"header":"Content-Type","value":"image/x-mrsid-image"},{"header":"Content-Type","value":"image/mrsid"}],"htmlAccept":"image/x-mrsid-image, .sid","fileDetection":["MrSID files consistently begin with the 4-byte ASCII signature 'msid' (Hex: 6D 73 69 64).","They are frequently accompanied by a sidecar '.sdw' (MrSID World File) which contains the spatial reference parameters needed to anchor the image to geographic coordinates."]},"prosCons":{"pros":["Incredible compression ratios enable multi-gigabyte geographical datasets to be stored on standard hard drives or transmitted easily","Multi-resolution architecture means panning and zooming across a massive map is completely fluid, as the system decodes only the visible quadrant at the required zoom level","Supports multi-spectral bands critical for remote sensing and agricultural GIS analysis"],"cons":["Deeply proprietary; creating or decoding MrSID files typically requires expensive commercial software or the proprietary Extensis DSDK","Open-source geospatial libraries like GDAL require compiling against the proprietary SDK to legally enable MrSID support, causing licensing headaches for Linux server deployments","Not natively viewable on the web without specialized geospatial map servers (like GeoServer or MapServer) tiling the image into PNGs or JPEGs on the fly"]},"specifications":{"url":"https://www.extensis.com/support/mrsid-technology","rfc":"","mimeAliases":["image/mrsid","application/x-mrsid"]},"developerSnippets":{"python":"import magic\n# Libmagic will reliably detect the 'msid' signature for MrSID files\nprint(magic.from_file('satellite_map.sid', mime=True)) # Outputs 'image/x-mrsid-image' or similar custom MIME","nodejs":"const fs = require('fs');\n// Manually detecting the 'msid' 4-byte signature\nconst buffer = Buffer.alloc(4);\nconst fd = fs.openSync('satellite_map.sid', 'r');\nfs.readSync(fd, buffer, 0, 4, 0);\nfs.closeSync(fd);\nconst isMrSID = buffer.toString('ascii') === 'msid';\nconsole.log('Is Extensis MrSID:', isMrSID);","go":"import (\n    \"bytes\"\n    \"net/http\"\n)\n// Native Go HTTP detection will default to application/octet-stream.\n// Check directly for the explicit 4-byte signature:\n// isMrSID := bytes.HasPrefix(buf, []byte(\"msid\"))","php":"$mime = mime_content_type('satellite_map.sid');\necho $mime; // Without custom GIS magic definitions, this will resolve to 'application/octet-stream'"},"relatedFormats":["tiff","jp2"]}