Image MIME Reference
JPEG-XS-Codestream
JPEG XS Codestream
image/jxsc
VS
Microsoft Image Extension
image/vnd.mix
MIX
A complete technical comparison of JPEG XS Codestream and Microsoft Image Extension — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | JPEG-XS-Codestream | MIX |
|---|---|---|
| Transparency (Alpha) | Yes | Yes |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | Yes | ✕ No |
| EXIF Metadata | ✕ No | ✕ No |
| ICC Color Profile | ✕ No | Yes |
JPEG XS Codestream
image/jxsc
Extension
.jxsc.jxs
Container
None (Raw Codestream)
Compression
Lossy (Visually Lossless) / Mathematically Lossless
Algorithm
JPEG XS (ISO/IEC 21122-1)
Color Depth
8-bit, 10-bit, 12-bit, 14-bit, 16-bit
Developed by
Joint Photographic Experts Group (JPEG) / intoPIX
Released
2019
Magic Bytes
FF 10
Microsoft Image Extension
image/vnd.mix
Extension
.mix
Container
Microsoft OLE Structured Storage (COM)
Compression
Proprietary (Internal JPEG/RLE)
Algorithm
JPEGDeflateProprietary
Color Depth
8-bit, 24-bit, 32-bit (RGBA)
Developed by
Microsoft Corporation
Released
1996
Magic Bytes
D0 CF 11 E0 A1 B1 1A E1
Browser Support Comparison
| Browser | JPEG-XS-Codestream | MIX |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
JPEG-XS-Codestream
JPEG-XS-Codestream Strengths
- Eliminates container overhead, maximizing parsing speed and minimizing latency to fractions of a millisecond
- Highly optimized for direct hardware implementation in FPGAs and ASICs
- Perfect for continuous data streaming over IP networks without needing to establish file headers
Limitations
- Lacks standard container metadata (EXIF, XMP, ICC profiles), meaning color space and orientation data must be handled externally or out-of-band
- Zero support in web browsers or standard consumer operating systems
- Often requires specialized broadcast hardware or custom software libraries to decode
MIX
MIX Strengths
- Allowed early consumer software to non-destructively edit complex compositions involving photos, text, and vector clipart
- Shared an architecture with other Microsoft Office products, enabling deep integration (OLE embedding) into Word and PowerPoint at the time
Limitations
- Completely proprietary and undocumented, leading to a massive loss of historical data for users who archived their family photos in this project format
- Requires traversing a complex OLE filesystem just to extract the flattened raster image
- No support in modern image editors like Photoshop, GIMP, or web browsers
When to choose which format
JPEG-XS-Codestream
Use JPEG-XS-Codestream when…
- Hardware Decoding Pipelines (FPGA/ASIC)
- Live Broadcast Infrastructure
- Video over IP Transport
- Embedded Camera Systems
MIX
Use MIX when…
- Historical Microsoft Picture It! Projects
- Microsoft PhotoDraw 2000 Graphics
- Early 2000s Consumer Digital Scrapbooking