Image MIME Reference
Corel-CMX
Corel Metafile Exchange
image/x-cmx
VS
JPEG XR Image Sequence (HEIF Container)
image/jxrs
JPEG-XR-Sequence
A complete technical comparison of Corel Metafile Exchange and JPEG XR Image Sequence (HEIF Container) — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | Corel-CMX | JPEG-XR-Sequence |
|---|---|---|
| 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 XR Image Sequence (HEIF Container)
image/jxrs
Extension
.jxrs
Container
HEIF / ISOBMFF (ISO/IEC 23008-12 / Annex F of ITU-T T.832)
Compression
Lossy / Lossless
Algorithm
JPEG XR (Lapped Biorthogonal Transform)
Color Depth
8-bit, 16-bit, 32-bit (Float)
Developed by
ISO/IEC JTC 1 / ITU-T
Released
2019
Magic Bytes
XX XX XX XX 66 74 79 70 6A 78 72 53
Browser Support Comparison
| Browser | Corel-CMX | JPEG-XR-Sequence |
|---|---|---|
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- Largely obsolete for modern workflows, superseded by PDF and SVG
JPEG-XR-Sequence
JPEG-XR-Sequence Strengths
- Supports 32-bit floating point HDR color depths natively across an entire animation sequence
- Combines the advanced coding efficiencies of JPEG XR with the sequence timing and metadata framework of HEIF
- Shares frame data structures allowing for optimized storage of burst photography
Limitations
- Extremely rare format with essentially no mainstream software adoption
- Zero web browser support
- Overshadowed heavily by HEVC (HEIC sequences) and AV1 (AVIF sequences) which offer superior compression and broader hardware decoding 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
JPEG-XR-Sequence
Use JPEG-XR-Sequence when…
- Experimental Animation Workflows
- HDR Burst Photography Archiving
- Specialized Medical & Scientific Imaging