Free webp to jpg
Image MIME Reference
Fuji-RAF

Fujifilm RAW Image

image/x-fuji-raf
VS

JPEG-LS

image/jls
JPEG-LS

A complete technical comparison of Fujifilm RAW Image and JPEG-LS — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

Equal browser support

Feature Support

Feature Fuji-RAF JPEG-LS
Transparency (Alpha) ✕ No ✕ No
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
Full Fuji-RAF reference →
JPEG-LS
image/jls
Extension
.jls.jl
Container JPEG Bitstream
Compression Lossless / Near-Lossless (Predictive Coding)
Algorithm
LOCO-I (Low Complexity Lossless Compression for Images)Golomb-Rice Coding
Color Depth 8-bit, 12-bit, 16-bit (Per Channel)
Developed by Joint Photographic Experts Group (ISO/ITU-T) & HP Labs
Released 1999
Magic Bytes
FF D8 FF F7
Full JPEG-LS reference →

Browser Support Comparison

Browser Fuji-RAF JPEG-LS
Chrome Chrome
Firefox Firefox
Safari Safari
Edge Edge
IE 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-LS

JPEG-LS Strengths

  • Provides state-of-the-art lossless compression ratios for continuous-tone images, often outperforming Lossless JPEG and JPEG 2000
  • Extremely fast and computationally inexpensive to encode/decode, requiring no complex floating-point math or DCTs
  • Highly resilient in constrained hardware environments, making it ideal for medical equipment and deep-space probes (e.g., Mars rovers)
Limitations
  • Zero native support in web browsers or standard consumer operating systems
  • Lacks the advanced resolution scalability and progressive decoding features found in JPEG 2000
  • Primarily relegated to niche enterprise sectors (healthcare/DICOM and aerospace) rather than consumer adoption

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-LS
Use JPEG-LS when…
  • Medical Imaging (DICOM Encapsulation)
  • Space and Planetary Imaging (NASA/ESA)
  • Industrial Machine Vision
  • Scientific Archival Storage
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