Image MIME Reference
Corel-CMX
Corel Metafile Exchange
image/x-cmx
VS
JPEG 2000 Image Sequence (Obsolete)
image/hsj2
HSJ2
A complete technical comparison of Corel Metafile Exchange and JPEG 2000 Image Sequence (Obsolete) — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | Corel-CMX | HSJ2 |
|---|---|---|
| Transparency (Alpha) | Yes | Yes |
| Animation Support | ✕ No | Yes |
| Progressive Loading | ✕ No | Yes |
| HDR Support | ✕ No | Yes |
| EXIF Metadata | ✕ No | Yes |
| 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
JPEG 2000 Image Sequence (Obsolete)
image/hsj2
Extension
.hsj2
Container
HEIF / ISOBMFF (ISO/IEC 15444-16 Obsolete)
Compression
Lossy / Lossless
Algorithm
Motion JPEG 2000 (ISO/IEC 15444-3)
Color Depth
8-bit, 10-bit, 12-bit, 16-bit
Developed by
ISO/IEC JTC 1 / ITU-T
Released
2019
Magic Bytes
XX XX XX XX 66 74 79 70 68 73 6A 32
Browser Support Comparison
| Browser | Corel-CMX | HSJ2 |
|---|---|---|
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- Largely obsolete for modern workflows, superseded by PDF and SVG
HSJ2
HSJ2 Strengths
- Historically attempted to combine Motion JPEG 2000 sequences with the flexible metadata capabilities of the HEIF container
- Supported mathematically lossless compression and scalable wavelet decoding
Limitations
- Officially deprecated by the standardization body (ISO/IEC JTC 1)
- Completely superseded by image/hej2k, rendering hsj2 files obsolete for any new development or archiving
- Zero web browser compatibility and negligible modern software support
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
HSJ2
Use HSJ2 when…
- Legacy Archival
- Deprecated Workflows