Image MIME Reference
Minolta-MRW
Minolta Raw Image
image/x-minolta-mrw
VS
Portable Bitmap
image/x-portable-bitmap
PBM
A complete technical comparison of Minolta 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 | Minolta-MRW | 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 |
Minolta Raw Image
image/x-minolta-mrw
Extension
.mrw
Container
Proprietary MRW Container
Compression
Uncompressed / Proprietary Lossless
Algorithm
NoneProprietary Lossless
Color Depth
12-bit (Per Channel)
Developed by
Minolta (later Konica Minolta)
Released
2001
Magic Bytes
00 4D 52 4D
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 | Minolta-MRW | PBM |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
Minolta-MRW
Minolta-MRW Strengths
- Retains full, unadulterated sensor data from early CCD digital cameras, allowing modern demosaicing algorithms to extract far superior image quality than what was possible when the cameras were released
- Possesses a very distinct, unambiguous magic header (\x00MRM), making programmatic identification completely foolproof
Limitations
- Completely obsolete proprietary format that has not seen a new camera release since 2006
- Cannot be natively viewed in web browsers or standard operating system image viewers without specialized decoders
- Relies entirely on open-source reverse engineering (like LibRaw) for continued modern software compatibility
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
Minolta-MRW
Use Minolta-MRW when…
- Vintage Digital Photography (Konica Minolta DiMAGE / Maxxum)
- Raw Imaging Archival
- Historical Camera Sensor Research
PBM
Use PBM when…
- Optical Character Recognition (OCR) Pre-processing
- Unix/Linux Command-Line Image Pipelines
- Academic Image Processing Teaching