Image MIME Reference
Corel-CMX
Corel Metafile Exchange
image/x-cmx
VS
Global Graphics Page Graphics Buffer
image/vnd.globalgraphics.pgb
Harlequin-PGB
A complete technical comparison of Corel Metafile Exchange and Global Graphics Page Graphics Buffer — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | Corel-CMX | Harlequin-PGB |
|---|---|---|
| Transparency (Alpha) | Yes | ✕ No |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | ✕ No | ✕ No |
| EXIF Metadata | ✕ No | ✕ No |
| ICC Color Profile | Yes | Yes |
Corel Metafile Exchange
image/x-cmx
Extension
.cmx
Container
RIFF (Resource Interchange File Format)
Compression
Uncompressed Vector Commands / Embedded Raster Compression (Optional)
Algorithm
None (Vector)
Color Depth
Vector Data, Supports embedded bitmaps
Developed by
Corel Corporation
Released
Mid-1990s
Magic Bytes
52 49 46 46 (skip 4) 43 4D 58 31
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)
Browser Support Comparison
| Browser | Corel-CMX | Harlequin-PGB |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
Corel-CMX
Corel-CMX Strengths
- Preserves rich vector attributes and layer groupings native to the Corel drawing engine better than standard WMF files
- Significantly smaller footprint than full CDR project files, making it excellent for early CD-ROM clip art distribution
- Maintains decent support in the open-source community thanks to libraries like libcdr
Limitations
- Proprietary format strictly tied to Corel's ecosystem, often causing compatibility issues with Adobe software
- Zero support in web browsers; must be converted to SVG for modern web usage
- Largely obsolete for modern workflows, superseded by PDF and SVG
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
When to choose which format
Corel-CMX
Use Corel-CMX when…
- Legacy CorelDRAW Clip Art Collections
- Vector Graphic Exchange within Corel Suite
- Historical Desktop Publishing Assets
Harlequin-PGB
Use Harlequin-PGB when…
- Commercial Printing Output
- Computer-to-Plate (CTP) Manufacturing
- Prepress Soft Proofing (e.g., FirstPROOF)
- Harlequin RIP Spooling Pipelines