Image MIME Reference
JPEG-XR-Sequence
JPEG XR Image Sequence (HEIF Container)
image/jxrs
VS
JPEG 2000 Part 2 (Extended)
image/jpx
JPX
A complete technical comparison of JPEG XR Image Sequence (HEIF Container) and JPEG 2000 Part 2 (Extended) — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | JPEG-XR-Sequence | JPX |
|---|---|---|
| Transparency (Alpha) | Yes | Yes |
| Animation Support | Yes | Yes |
| Progressive Loading | Yes | Yes |
| HDR Support | Yes | Yes |
| EXIF Metadata | Yes | Yes |
| ICC Color Profile | Yes | Yes |
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
JPEG 2000 Part 2 (Extended)
image/jpx
Extension
.jpx.jpf
Container
ISOBMFF / JPX (ISO/IEC 15444-2)
Compression
Lossy / Lossless
Algorithm
Discrete Wavelet Transform (DWT)
Color Depth
8-bit, 16-bit, 32-bit, 38-bit
Developed by
Joint Photographic Experts Group (JPEG)
Released
2002
Magic Bytes
00 00 00 0C 6A 50 20 20 0D 0A 87 0A ... 66 74 79 70 6A 70 78 20
Browser Support Comparison
| Browser | JPEG-XR-Sequence | JPX |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
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
JPX
JPX Strengths
- Removes the color space limitations of baseline JP2, adding native support for CMYK, CIE Lab, and custom vendor color spaces
- Supports multiple codestreams in a single file, allowing for rich compositing and animation
- Enables fragmented files where image data and metadata can reside in separate physical files via data references
Limitations
- Extremely complex specification makes full software implementation rare, leading to compatibility issues
- Zero web browser support, rendering it unsuitable for public internet distribution
- Often overkill for standard imaging tasks where baseline JP2 or modern alternatives like AVIF suffice
When to choose which format
JPEG-XR-Sequence
Use JPEG-XR-Sequence when…
- Experimental Animation Workflows
- HDR Burst Photography Archiving
- Specialized Medical & Scientific Imaging
JPX
Use JPX when…
- Prepress & Commercial Printing (CMYK)
- Geospatial Data
- Archival Preservation
- Medical Imaging