{"id":"image-j2c","mimeType":"image/j2c","name":"JPEG 2000 Codestream","shortName":"J2C","category":"Photography \u0026 Broadcast","extensions":[".j2c",".j2k",".jpc"],"description":"The image/j2c MIME type represents a raw JPEG 2000 Codestream. Unlike the standard image/jp2 format, which encapsulates the image in a structured container alongside color profiles and metadata, an image/j2c file contains only the raw, wavelet-compressed pixel data. It is heavily used in professional broadcasting, Digital Cinema Packages (DCP), and medical imaging architectures where metadata and timing are handled externally by multiplexing formats (like MXF).","seo":{"title":"image/j2c MIME Type | Complete Developer Reference \u0026 Magic Bytes","description":"Complete reference for the image/j2c MIME type: magic bytes, the difference between JP2 and J2C codestreams, HTTP headers, and technical specifications.","faqs":[{"question":"What is the difference between JP2 and J2C?","answer":"JP2 (image/jp2) is a container format that includes a JPEG 2000 codestream alongside essential metadata like ICC color profiles, resolution, and EXIF data. J2C (image/j2c) is purely the raw, compressed image data stream (the codestream) stripped of this outer container."},{"question":"What are the magic bytes for a J2C codestream?","answer":"A raw JPEG 2000 codestream always begins with the Start of Codestream (SOC) marker, which is the 2-byte hex sequence FF 4F. This is immediately followed by the Image and Tile Size (SIZ) marker, FF 51. So, the first 4 bytes are typically FF 4F FF 51."},{"question":"Can I display image/j2c files in a web browser?","answer":"No. While Apple's Safari browser has native support for the JP2 container format, no modern web browsers support decoding raw J2C codestreams. For web delivery, they must be converted to standard formats like WebP, AVIF, or JPEG."}]},"index":{"compression":["JPEG 2000 (Discrete Wavelet Transform)","Lossless","Lossy"],"browserSupport":{"score":1,"label":"None"},"commonUses":["Digital Cinema Packages (DCP)","Medical Imaging (DICOM Payloads)","Professional Broadcast and Archiving","Embedded Hardware Encoding"]},"technical":{"magicBytes":{"hex":"FF 4F FF 51","ascii":"ÿOÿQ"},"container":"None (Raw Bitstream)","compressionAlgorithm":["Discrete Wavelet Transform (DWT)"],"colorDepth":["8-bit","10-bit","12-bit","16-bit (Per Channel)"],"transparency":true,"animation":false,"metadata":{"exif":false,"xmp":false,"iccProfile":false},"alphaChannel":true,"progressiveLoading":true,"hdrSupport":true},"history":{"developer":"Joint Photographic Experts Group (JPEG)","released":"2000","specification":"ISO/IEC 15444-1 (JPEG 2000 Core Coding System)"},"browserSupport":{"chrome":false,"chromeVersion":"None","firefox":false,"firefoxVersion":"None","safari":false,"safariVersion":"None","edge":false,"edgeVersion":"None","internetExplorer":false},"softwareSupport":[{"name":"FFmpeg","logo":""},{"name":"ImageMagick","logo":"image-magic.webp"},{"name":"OpenJPEG","logo":""},{"name":"Kakadu Software","logo":""}],"conversion":{"convertTo":["jp2","jpeg","png","tiff","webp"],"convertFrom":["jp2","jpeg","tiff","png"]},"developer":{"httpHeaders":[{"header":"Content-Type","value":"image/j2c"}],"htmlAccept":"image/j2c, image/x-jp2-codestream, .j2c, .j2k, .jpc","fileDetection":["Check the first 2 bytes for the Start of Codestream (SOC) marker: FF 4F","Verify the following 2 bytes for the SIZ marker: FF 51","Unlike JP2 files which start with a standard box structure ('jP  ' / 00 00 00 0C 6A 50 20 20), J2C skips the container entirely and starts directly with the SOC marker."]},"prosCons":{"pros":["Provides state-of-the-art wavelet compression for high-end professional workflows (Digital Cinema)","Allows for highly efficient progressive decoding (by resolution or quality layer) natively within the stream","Supports lossless mathematical compression and high bit-depths (up to 16-bit per channel) natively"],"cons":["Lacks a standard container to store color space info or metadata, requiring external systems (like MXF or DICOM) to map colors correctly","Extremely computationally expensive to encode and decode compared to standard DCT-based JPEG","Zero web browser support"]},"specifications":{"url":"https://jpeg.org/jpeg2000/","rfc":"RFC 3745","mimeAliases":["image/x-jp2-codestream"]},"developerSnippets":{"python":"import magic\n# Libmagic accurately detects the SOC marker for JPEG 2000 codestreams\nprint(magic.from_file('stream.j2c', mime=True)) # Outputs 'image/j2c'","nodejs":"const FileType = require('file-type');\nconst type = await FileType.fromFile('stream.j2c');\nconsole.log(type.mime); // Outputs 'image/j2c'","go":"import \"net/http\"\n// Custom byte sniff required for raw J2C since net/http might miss it\n// isJ2C := bytes.HasPrefix(buf, []byte{0xFF, 0x4F, 0xFF, 0x51})","php":"$mime = mime_content_type('stream.j2c');\necho $mime; // Standard setups generally resolve this to 'image/j2c'"},"relatedFormats":["jpx","jpeg","tiff"]}