{"id":"image-jph","mimeType":"image/jph","name":"High-Throughput JPEG 2000 Image","shortName":"HTJ2K-(JPH)","category":"Professional \u0026 Archival","extensions":[".jph"],"description":"The image/jph MIME type represents the JPH file format, which encapsulates High-Throughput JPEG 2000 (HTJ2K) codestreams. Standardized as ISO/IEC 15444-15 (JPEG 2000 Part 15), HTJ2K replaces the original JPEG 2000 block coder with an extremely fast, parallelizable block coder. This allows for an order of magnitude faster encoding and decoding while preserving advanced features like mathematically lossless compression and resolution scalability.","seo":{"title":"image/jph MIME Type | Complete Developer Reference \u0026 Magic Bytes","description":"Complete reference for the image/jph MIME type: magic bytes, browser support, HTTP headers, developer snippets, and technical specifications for High-Throughput JPEG 2000 (HTJ2K).","faqs":[{"question":"What is the difference between JP2 and JPH?","answer":"Both are container formats in the JPEG 2000 family based on the box-structured architecture. While JP2 (image/jp2) uses the original JPEG 2000 block coder (Part 1), JPH specifically encapsulates High-Throughput JPEG 2000 (HTJ2K, Part 15) codestreams designed for significantly faster, parallelized processing."},{"question":"What is the magic byte for a JPH file?","answer":"A JPH file begins with the standard 12-byte JPEG 2000 signature box (00 00 00 0C 6A 50 20 20 0D 0A 87 0A). This is immediately followed by the 'ftyp' (File Type) box, which explicitly contains the major brand 'jph ' (6A 70 68 20 in hex)."},{"question":"Are HTJ2K / JPH images supported in web browsers?","answer":"No. Like standard JPEG 2000, there is no native support for High-Throughput JPEG 2000 in modern web browsers. It is primarily used in specialized imaging fields such as medical imaging (DICOM), geospatial analysis, digital cinema, and professional archiving."}]},"index":{"compression":["Lossy","Lossless"],"browserSupport":{"score":1,"label":"None"},"commonUses":["Medical Imaging (DICOM)","Geospatial Data","Digital Cinema","Professional Archiving"]},"technical":{"magicBytes":{"hex":"00 00 00 0C 6A 50 20 20 0D 0A 87 0A ... 66 74 79 70 6A 70 68 20","ascii":"....jP  ........ftypjph "},"container":"JPH (ISO/IEC 15444-15)","compressionAlgorithm":["High-Throughput JPEG 2000 (HTJ2K)"],"colorDepth":["8-bit","16-bit","32-bit","38-bit"],"transparency":true,"animation":false,"metadata":{"exif":true,"xmp":true,"iccProfile":true},"alphaChannel":true,"progressiveLoading":true,"hdrSupport":true},"history":{"developer":"Joint Photographic Experts Group (JPEG)","released":"2019","specification":"ISO/IEC 15444-15 (JPEG 2000 Part 15)"},"browserSupport":{"chrome":false,"chromeVersion":"None","firefox":false,"firefoxVersion":"None","safari":false,"safariVersion":"None","edge":false,"edgeVersion":"None","internetExplorer":false},"softwareSupport":[{"name":"OpenJPH","logo":""},{"name":"Kakadu Software","logo":""},{"name":"Grok","logo":""},{"name":"ImageMagick","logo":"image-magic.webp"}],"conversion":{"convertTo":["jp2","jpeg","png","tiff"],"convertFrom":["jp2","jpeg","tiff"]},"developer":{"httpHeaders":[{"header":"Content-Type","value":"image/jph"}],"htmlAccept":"image/jph, .jph","fileDetection":["Check the first 12 bytes for the JPEG 2000 signature box (00 00 00 0C 6A 50 20 20 0D 0A 87 0A)","Check the immediately following File Type (ftyp) box to ensure the major brand string is 'jph ' (6A 70 68 20) to confirm it is an HTJ2K file rather than a standard JP2 file"]},"prosCons":{"pros":["Delivers orders of magnitude faster encoding and decoding than standard JPEG 2000 by utilizing a new, parallelizable block coder","Supports mathematically lossless and lossy compression within the same codestream architecture","Allows for resolution scalability, progressive decoding, and region-of-interest extraction without needing to decode the entire image"],"cons":["Zero native web browser support, requiring specialized libraries, API conversions, or WebAssembly (like OpenJPH.js) for web deployment","Lack of broad consumer awareness, keeping it confined to professional, medical, and scientific workflows","Requires more advanced software ecosystems to decode than ubiquitous formats like JPEG or WebP"]},"specifications":{"url":"https://htj2k.com/","rfc":"","mimeAliases":["image/x-jph"]},"developerSnippets":{"python":"import magic\nprint(magic.from_file('image.jph', mime=True)) # May default to generic 'image/jp2' or 'application/octet-stream' without an updated magic database","nodejs":"const FileType = require('file-type');\nconst type = await FileType.fromFile('image.jph');\nconsole.log(type?.mime); // Standard parsers may miss the specific 'jph ' brand check","go":"import \"net/http\"\n// Custom ISOBMFF box parsing is required to read the 'jph ' brand inside the ftyp box.","php":"$mime = mime_content_type('image.jph');\necho $mime; // Standard implementations often map this to application/octet-stream"},"relatedFormats":["hej2k","tiff"]}