Image MIME Reference
Harlequin-PGB
Global Graphics Page Graphics Buffer
image/vnd.globalgraphics.pgb
VS
Minolta Raw Image
image/x-minolta-mrw
Minolta-MRW
A complete technical comparison of Global Graphics Page Graphics Buffer and Minolta Raw Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | Harlequin-PGB | Minolta-MRW |
|---|---|---|
| Transparency (Alpha) | ✕ No | ✕ No |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | ✕ No | Yes |
| EXIF Metadata | ✕ No | Yes |
| ICC Color Profile | Yes | Yes |
Global Graphics Page Graphics Buffer
image/vnd.globalgraphics.pgb
Extension
.pgb
Container
Proprietary Harlequin Raster Container
Compression
Uncompressed / Run-Length Encoding (RLE)
Algorithm
Proprietary RLENone
Color Depth
1-bit (Monochrome Separations), 8-bit (Grayscale), 8-bit/10-bit (Contone), CMYK / N-Color Spot Channels
Developed by
Global Graphics Software (Hybrid Software Group)
Released
1990s
Magic Bytes
Unknown (Proprietary Harlequin Header)
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
Browser Support Comparison
| Browser | Harlequin-PGB | Minolta-MRW |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
Harlequin-PGB
Harlequin-PGB Strengths
- Unlike generic 1-bit TIFFs, PGB files inherently encapsulate vital print-job metadata within their headers (e.g., job name, page number, separation colors, screening angles)
- Highly optimized for ultra-fast viewing and processing within professional printing workflows
Limitations
- Completely proprietary and closed-source, locking its usage strictly to Harlequin-powered RIP environments
- Zero support in standard desktop operating systems, web browsers, or consumer image editing software like Photoshop or GIMP
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
When to choose which format
Harlequin-PGB
Use Harlequin-PGB when…
- Commercial Printing Output
- Computer-to-Plate (CTP) Manufacturing
- Prepress Soft Proofing (e.g., FirstPROOF)
- Harlequin RIP Spooling Pipelines
Minolta-MRW
Use Minolta-MRW when…
- Vintage Digital Photography (Konica Minolta DiMAGE / Maxxum)
- Raw Imaging Archival
- Historical Camera Sensor Research