{"id":"image-jxra","mimeType":"image/jxra","name":"JPEG XR Image (HEIF Container)","shortName":"JPEG-XR-(HEIF)","category":"Photography \u0026 Archival","extensions":[".jxra"],"description":"The image/jxra MIME type (often styled as image/jxrA) represents a JPEG XR (Extended Range) single image or image collection encapsulated within the High Efficiency Image File Format (HEIF) container. Standardized in Annex F of ITU-T T.832, it combines the powerful compression and HDR capabilities of JPEG XR with the flexible metadata and box structure of the ISOBMFF-based HEIF container.","seo":{"title":"image/jxra MIME Type | Complete Developer Reference \u0026 Magic Bytes","description":"Complete reference for the image/jxra MIME type: magic bytes, software support, HTTP headers, developer snippets, and technical specifications for HEIF-encapsulated JPEG XR images.","faqs":[{"question":"What is the difference between image/jxr and image/jxra?","answer":"image/jxr refers to the original JPEG XR image format (previously Microsoft HD Photo), which utilizes a TIFF-like file structure. image/jxra represents JPEG XR compressed data housed within a modern HEIF (High Efficiency Image File Format) container."},{"question":"What is the magic byte for an image/jxra file?","answer":"Because it relies on the HEIF/ISOBMFF container format, an image/jxra file begins with a 4-byte box size, followed by the 'ftyp' box identifier, and the major brand 'jxrA'. In hex, this signature is XX XX XX XX 66 74 79 70 6A 78 72 41."},{"question":"Is image/jxra widely supported in web browsers or software?","answer":"No. While HEIF containers are popular for storing HEVC-encoded images (HEIC), embedding JPEG XR data inside HEIF is extremely rare. There is zero native web browser support, and it is largely confined to experimental workflows or highly specialized archival standards."}]},"index":{"compression":["Lossy","Lossless"],"browserSupport":{"score":1,"label":"None"},"commonUses":["Specialized Archival","Experimental Imaging Workflows","High Dynamic Range (HDR) Imaging"]},"technical":{"magicBytes":{"hex":"XX XX XX XX 66 74 79 70 6A 78 72 41","ascii":"....ftypjxrA"},"container":"HEIF / ISOBMFF (ISO/IEC 23008-12 / Annex F of ITU-T T.832)","compressionAlgorithm":["JPEG XR (Lapped Biorthogonal Transform)"],"colorDepth":["8-bit","16-bit","32-bit (Float)"],"transparency":true,"animation":false,"metadata":{"exif":true,"xmp":true,"iccProfile":true},"alphaChannel":true,"progressiveLoading":true,"hdrSupport":true},"history":{"developer":"ISO/IEC JTC 1 / ITU-T","released":"2019","specification":"ITU-T T.832 Annex F / ISO/IEC 29199-2:2019"},"browserSupport":{"chrome":false,"chromeVersion":"None","firefox":false,"firefoxVersion":"None","safari":false,"safariVersion":"None","edge":false,"edgeVersion":"None","internetExplorer":false},"softwareSupport":[{"name":"ImageMagick","logo":"image-magic.webp"}],"conversion":{"convertTo":["jxr","heic","jpeg","png"],"convertFrom":["jxr","jpeg","tiff"]},"developer":{"httpHeaders":[{"header":"Content-Type","value":"image/jxra"},{"header":"Content-Type","value":"image/jxrA"}],"htmlAccept":"image/jxra, image/jxrA, .jxra","fileDetection":["Check for the standard ISOBMFF 'ftyp' box starting at byte offset 4","Verify the major brand string starting at byte offset 8 is exactly 'jxrA' (6A 78 72 41)"]},"prosCons":{"pros":["Combines the deep color (32-bit float) and mathematically lossless compression of JPEG XR with the robust metadata architecture of HEIF","Allows grouping multiple images, exposure brackets, or focal stacks into a single file collection"],"cons":["Practically non-existent software and operating system support compared to standard HEIC or legacy JPEG XR (.jxr)","Zero web browser support, rendering it entirely unsuitable for public web deployment","Eclipsed by modern standards like AVIF and JPEG XL which offer superior compression with much broader industry backing"]},"specifications":{"url":"https://www.itu.int/rec/T-REC-T.832","rfc":"","mimeAliases":["image/jxrA"]},"developerSnippets":{"python":"import magic\nprint(magic.from_file('photo.jxra', mime=True)) # Will likely default to generic 'image/heif' or 'application/octet-stream' without manual configuration","nodejs":"const FileType = require('file-type');\nconst type = await FileType.fromFile('photo.jxra');\nconsole.log(type?.mime); // Standard parsers may fail to recognize the specific 'jxrA' brand","go":"import \"net/http\"\n// The standard net/http library cannot detect specific HEIF sub-brands.\n// Custom ISOBMFF box parsing is required to read the 'jxrA' string.","php":"$mime = mime_content_type('photo.jxra');\necho $mime; // Standard server environments will often resolve this to application/octet-stream"},"relatedFormats":["heif","jpx"]}