Image MIME Reference
Harlequin-PGB
Global Graphics Page Graphics Buffer
image/vnd.globalgraphics.pgb
VS
WebP Image
image/webp
WebP
A complete technical comparison of Global Graphics Page Graphics Buffer and WebP Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
WebP wins on browser support
Feature Support
| Feature | Harlequin-PGB | WebP |
|---|---|---|
| Transparency (Alpha) | ✕ No | Yes |
| Animation Support | ✕ No | Yes |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | ✕ No | ✕ No |
| 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)
WebP Image
image/webp
Extension
.webp
Container
RIFF
Compression
Lossy / Lossless
Algorithm
VP8VP8L
Color Depth
8-bit
Developed by
Google
Released
2010
Magic Bytes
52 49 46 46 XX XX XX XX 57 45 42 50
Browser Support Comparison
| Browser | Harlequin-PGB | WebP |
|---|---|---|
Chrome
|
✕ |
✓ 32+
|
Firefox
|
✕ |
✓ 65+
|
Safari
|
✕ |
✓ 14+
|
Edge
|
✕ |
✓ 18+
|
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
WebP
WebP Strengths
- Superior lossy compression — 25–35% smaller than JPEG at equivalent quality
- Supports both animation and full alpha transparency
- Lossless mode available with smaller file sizes than PNG
Limitations
- Slower encoding than JPEG, especially for lossless
- Not supported in Internet Explorer or very old browsers
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
WebP
Use WebP when…
- Websites
- Ecommerce
- Mobile Apps
- CMS Images