{"id":"image-x-canon-crw","mimeType":"image/x-canon-crw","name":"Canon Raw Format","shortName":"Canon-CRW","category":"Photography \u0026 Raw Imaging","extensions":[".crw"],"description":"The image/x-canon-crw MIME type represents the first-generation Canon Raw (CRW) file format, introduced in the late 1990s and used heavily in early-2000s digital cameras (such as the Canon EOS D30, 10D, Digital Rebel/300D, and early PowerShot G series). Unlike its successor (CR2), which is built on the TIFF standard, CRW is based on the proprietary Camera Image File Format (CIFF) structure. It stores minimally processed, losslessly compressed sensor data, basic EXIF metadata, and embedded thumbnail previews. It was officially superseded by the CR2 format in 2004.","seo":{"title":"image/x-canon-crw MIME Type | Developer Reference for Canon CRW","description":"Complete reference for the image/x-canon-crw MIME type: Canon Raw (CRW) format, CIFF structure, early digital camera history, and legacy raw imaging.","faqs":[{"question":"What is a CRW file?","answer":"A CRW file is a legacy raw image file generated by early Canon digital cameras (manufactured prior to 2004). It contains raw, unprocessed sensor data that requires specialized software to 'develop' into a standard viewable image."},{"question":"What is the difference between Canon CRW and CR2?","answer":"CRW is Canon's first-generation raw format based on the Camera Image File Format (CIFF) tree structure. CR2 is the second-generation format (introduced in 2004) that abandoned CIFF in favor of the more universally supported TIFF file structure."},{"question":"How do I open or convert a CRW file today?","answer":"Despite its age, CRW is still broadly supported by professional photo editing software like Adobe Lightroom, Adobe Camera Raw, Capture One, and open-source raw converters like RawTherapee and darktable. You can use these tools to export the CRW into modern formats like JPEG, PNG, or DNG."}]},"index":{"compression":["Lossless JPEG (ITU-T81)"],"browserSupport":{"score":1,"label":"None"},"commonUses":["Historical Digital Photography (2000-2004)","Non-destructive Image Post-Processing","Raw Imaging Archival"]},"technical":{"magicBytes":{"hex":"49 49 1A 00 00 00 (Header) / 48 45 41 50 43 43 44 52 (HEAPCCDR signature near end)","ascii":"II\\x1a... / HEAPCCDR"},"container":"CIFF (Camera Image File Format)","compressionAlgorithm":["Lossless JPEG"],"colorDepth":["10-bit (Per Channel)","12-bit (Per Channel)"],"transparency":false,"animation":false,"metadata":{"exif":true,"xmp":false,"iccProfile":false},"alphaChannel":false,"progressiveLoading":false,"hdrSupport":true},"history":{"developer":"Canon Inc.","released":"1998","specification":"Proprietary (CIFF Specification v1.0)"},"browserSupport":{"chrome":false,"chromeVersion":"None","firefox":false,"firefoxVersion":"None","safari":false,"safariVersion":"None","edge":false,"edgeVersion":"None","internetExplorer":false},"softwareSupport":[{"name":"Adobe Lightroom Classic / CC","logo":""},{"name":"Capture One","logo":""},{"name":"RawTherapee","logo":""},{"name":"ImageMagick","logo":"image-magic.webp"}],"conversion":{"convertTo":["dng","jpeg","tiff","png"],"convertFrom":[]},"developer":{"httpHeaders":[{"header":"Content-Type","value":"image/x-canon-crw"}],"htmlAccept":"image/x-canon-crw, .crw","fileDetection":["CRW files utilizing the CIFF format typically begin with the little-endian byte order mark 'II' (Hex: 49 49) followed by the heap start offset.","Unlike TIFF, the CIFF directory structure is located at the end of the file. A definitive identifier is the ASCII string 'HEAPCCDR' (Hex: 48 45 41 50 43 43 44 52) located near the EOF."]},"prosCons":{"pros":["Preserves original raw sensor data from foundational early digital SLR cameras, allowing for modern noise reduction and demosaicing algorithms to extract better images than software could in 2003","Files are remarkably small (often 6-8 MB) compared to modern 40MB+ raw files due to the lower megapixel count of early sensors"],"cons":["Completely obsolete and utilizes the idiosyncratic CIFF structure rather than the modern, standardized TIFF/EP structure","Cannot be natively viewed in web browsers or standard operating system image viewers without specialized codecs","Less robust metadata support compared to modern CR2 or CR3 formats"]},"specifications":{"url":"http://gvsoft.homedns.org/exif/CIFF-SpecV1R04.pdf","rfc":"","mimeAliases":["image/crw"]},"developerSnippets":{"python":"import magic\n# Libmagic can identify CRW files by recognizing the CIFF 'HEAPCCDR' tail or standard headers\nprint(magic.from_file('archive.crw', mime=True)) # Outputs 'image/x-canon-crw'","nodejs":"const FileType = require('file-type');\nconst type = await FileType.fromFile('archive.crw');\nconsole.log(type.mime); // Outputs 'image/x-canon-crw'","go":"import (\n    \"bytes\"\n    \"net/http\"\n)\n// Native Go HTTP detection does not recognize CIFF natively. \n// You must implement a custom parser to locate 'HEAPCCDR' near the EOF or check the 'II\\x1a' prefix.","php":"$mime = mime_content_type('archive.crw');\necho $mime; // Resolves to 'image/x-canon-crw' on updated servers"},"relatedFormats":["cr2","cr3","dng"]}