Image MIME Reference
Fuji-RAF
Fujifilm RAW Image
image/x-fuji-raf
VS
Portable Bitmap
image/x-portable-bitmap
PBM
A complete technical comparison of Fujifilm RAW Image and Portable Bitmap — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | Fuji-RAF | PBM |
|---|---|---|
| Transparency (Alpha) | ✕ No | ✕ No |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | Yes | ✕ No |
| 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
Portable Bitmap
image/x-portable-bitmap
Extension
.pbm
Container
Netpbm
Compression
Uncompressed
Algorithm
None
Color Depth
1-bit (Monochrome)
Developed by
Jef Poskanzer (Netpbm Project)
Released
1988
Magic Bytes
50 31 (ASCII) or 50 34 (Binary)
Browser Support Comparison
| Browser | Fuji-RAF | PBM |
|---|---|---|
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
PBM
PBM Strengths
- Absolute structural simplicity allows parsers to be written from scratch with just a few lines of code
- ASCII encoding allows manual editing and debugging directly within a standard text editor
- Serves as a flawless, lossless intermediary for 1-bit raster data like scanned documents or barcodes
Limitations
- Strictly limited to 1-bit monochrome images; cannot natively display shades of gray or color
- Lack of compression results in extremely large file sizes, particularly when using the ASCII 'P1' encoding
- No support for alpha transparency or modern metadata standards like EXIF
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
PBM
Use PBM when…
- Optical Character Recognition (OCR) Pre-processing
- Unix/Linux Command-Line Image Pipelines
- Academic Image Processing Teaching