Image MIME Reference
Harlequin-PGB
Global Graphics Page Graphics Buffer
image/vnd.globalgraphics.pgb
VS
QuickTime Image Format
image/x-quicktime
QTIF
A complete technical comparison of Global Graphics Page Graphics Buffer and QuickTime Image Format — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | Harlequin-PGB | QTIF |
|---|---|---|
| Transparency (Alpha) | ✕ No | Yes |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | ✕ No | ✕ No |
| EXIF Metadata | ✕ No | ✕ No |
| ICC Color Profile | Yes | ✕ No |
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)
QuickTime Image Format
image/x-quicktime
Extension
.qtif.qti.qif
Container
QuickTime Atom Container
Compression
Varies (JPEG, SMC, Apple Video, Cinepak, Uncompressed)
Algorithm
QuickTime Image Compression Manager (ICM) Codecs
Color Depth
1-bit to 32-bit (Varies depending on the enclosed codec)
Developed by
Apple Computer, Inc.
Released
1991
Magic Bytes
Varies (Typically begins with a 32-bit size integer followed by 69 64 73 63 ('idsc'))
Browser Support Comparison
| Browser | Harlequin-PGB | QTIF |
|---|---|---|
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
QTIF
QTIF Strengths
- Extremely flexible architecture allowing it to encapsulate virtually any image compression algorithm available on the host machine
- Supported 32-bit images with alpha channels (transparency) long before PNG became an established standard
Limitations
- Fundamentally tied to Apple's deprecated QuickTime architecture, rendering the files almost entirely unreadable on modern systems without specialized legacy software or FFmpeg
- The 'wrapper' nature of the format means that even if a parser can read the QTIF container, it may fail to render the image if it lacks the specific proprietary codec (like Apple SMC) used to compress the pixel data
- Zero native support in modern web 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
QTIF
Use QTIF when…
- Classic Mac OS Applications and Backgrounds
- QuickTime VR Panorama Textures
- 1990s CD-ROM Multimedia Assets