Image MIME Reference
CNS-INF2
Comverse Network Systems INF2 Image
image/vnd.cns.inf2
VS
JPEG XL
image/jxl
JXL
A complete technical comparison of Comverse Network Systems INF2 Image and JPEG XL — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
JXL wins on browser support
Feature Support
| Feature | CNS-INF2 | JXL |
|---|---|---|
| Transparency (Alpha) | ✕ No | Yes |
| Animation Support | ✕ No | Yes |
| Progressive Loading | ✕ No | Yes |
| HDR Support | ✕ No | Yes |
| EXIF Metadata | ✕ No | Yes |
| ICC Color Profile | ✕ No | Yes |
Comverse Network Systems INF2 Image
image/vnd.cns.inf2
Extension
.inf2
Container
Proprietary Comverse Container
Compression
Proprietary
Algorithm
Unknown (Proprietary Telecom Encoding)
Color Depth
Unknown
Developed by
Comverse Network Systems (Ann McLaughlin)
Released
1999
Magic Bytes
Unknown (Proprietary)
JPEG XL
image/jxl
Extension
.jxl
Container
ISOBMFF / JPEG XL Codestream
Compression
Lossy (VarDCT) / Lossless (Modular)
Algorithm
VarDCT (Variable block-size DCT)Modular (Predictive coding for lossless)
Color Depth
8-bit, 10-bit, 12-bit, 16-bit, 32-bit (Float)
Developed by
Joint Photographic Experts Group (JPEG)
Released
2021
Magic Bytes
FF 0A (Codestream) / 00 00 00 0C 4A 58 4C 20 0D 0A 87 0A (Container)
Browser Support Comparison
| Browser | CNS-INF2 | JXL |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ |
✓ 17+
|
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
CNS-INF2
CNS-INF2 Strengths
- Historically allowed Comverse to standardize media transmission internally across their global telecom messaging platforms
Limitations
- Completely obsolete and non-functional outside of decommissioned telecom infrastructure
- Undocumented, closed-source binary structure
- Zero support in modern image processing libraries like ImageMagick, libvips, or FFmpeg
JXL
JXL Strengths
- Capable of losslessly recompressing legacy JPEG files, saving ~20% space while retaining perfect byte-for-byte restorability
- Highly superior progressive decoding (Saliency-driven), allowing recognizable images to load extremely fast on slow connections
- Outperforms WebP and competes favorably with AVIF, especially at high-fidelity settings and for complex textures/photography
- Royalty-free with an open-source reference implementation (libjxl)
Limitations
- Google's removal of JXL support from Chrome severely hindered its adoption as a universal web standard
- Lack of hardware decoding chips compared to video-derived codecs like AVIF (AV1)
- File parsing logic is complex due to the split between raw codestreams and ISOBMFF containers
When to choose which format
CNS-INF2
Use CNS-INF2 when…
- Legacy Telecom Infrastructure
- Historical Comverse Unified Messaging Systems
- Proprietary Server-to-Server Media Exchange
JXL
Use JXL when…
- High-End Web Delivery (via Safari/Polyfills)
- HDR Photography
- Legacy JPEG Archiving
- Digital Art & Image Storage