Image MIME Reference
Fuji-RAF
Fujifilm RAW Image
image/x-fuji-raf
VS
JPEG XS Codestream
image/jxsc
JPEG-XS-Codestream
A complete technical comparison of Fujifilm RAW Image and JPEG XS Codestream — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | Fuji-RAF | JPEG-XS-Codestream |
|---|---|---|
| Transparency (Alpha) | ✕ No | Yes |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | Yes | Yes |
| EXIF Metadata | Yes | ✕ No |
| ICC Color Profile | Yes | ✕ No |
Fujifilm RAW Image
image/x-fuji-raf
Extension
.raf
Container
Proprietary RAF Container
Compression
Uncompressed / Lossless Compressed / Lossy Compressed (Modern firmware)
Algorithm
NoneProprietary LosslessProprietary Lossy
Color Depth
14-bit (Per Channel - X-Series), 16-bit (Per Channel - GFX Series)
Developed by
Fujifilm Corporation
Released
2000
Magic Bytes
46 55 4A 49 46 49 4C 4D 43 43 44 2D 52 41 57 20
JPEG XS Codestream
image/jxsc
Extension
.jxsc.jxs
Container
None (Raw Codestream)
Compression
Lossy (Visually Lossless) / Mathematically Lossless
Algorithm
JPEG XS (ISO/IEC 21122-1)
Color Depth
8-bit, 10-bit, 12-bit, 14-bit, 16-bit
Developed by
Joint Photographic Experts Group (JPEG) / intoPIX
Released
2019
Magic Bytes
FF 10
Browser Support Comparison
| Browser | Fuji-RAF | JPEG-XS-Codestream |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
Fuji-RAF
Fuji-RAF Strengths
- Retains absolute maximum sensor data, enabling massive shadow recovery and highlight protection compared to compressed in-camera JPEGs
- Stores proprietary Fujifilm Film Simulation metadata (like Classic Chrome or Acros), allowing editors to perfectly replicate in-camera aesthetics
- Very distinct and reliable magic header makes programmatic file detection foolproof
Limitations
- Proprietary format requires continuous updates to third-party software (like Lightroom) whenever Fujifilm releases a new camera
- The X-Trans sensor matrix requires highly specialized demosaicing algorithms that are extremely computationally expensive, leading to slower import and rendering times
- Completely unsupported in standard web browsers and basic operating system image viewers
JPEG-XS-Codestream
JPEG-XS-Codestream Strengths
- Eliminates container overhead, maximizing parsing speed and minimizing latency to fractions of a millisecond
- Highly optimized for direct hardware implementation in FPGAs and ASICs
- Perfect for continuous data streaming over IP networks without needing to establish file headers
Limitations
- Lacks standard container metadata (EXIF, XMP, ICC profiles), meaning color space and orientation data must be handled externally or out-of-band
- Zero support in web browsers or standard consumer operating systems
- Often requires specialized broadcast hardware or custom software libraries to decode
When to choose which format
Fuji-RAF
Use Fuji-RAF when…
- Professional Digital Photography
- Fujifilm X-Trans Sensor Image Archival
- High Dynamic Range (HDR) Post-Processing
JPEG-XS-Codestream
Use JPEG-XS-Codestream when…
- Hardware Decoding Pipelines (FPGA/ASIC)
- Live Broadcast Infrastructure
- Video over IP Transport
- Embedded Camera Systems