Image MIME Reference
JPX
JPEG 2000 Part 2 (Extended)
image/jpx
VS
Kodak Digital Camera Raw
image/x-kodak-dcr
Kodak-DCR
A complete technical comparison of JPEG 2000 Part 2 (Extended) and Kodak Digital Camera Raw — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | JPX | Kodak-DCR |
|---|---|---|
| Transparency (Alpha) | Yes | ✕ No |
| Animation Support | Yes | ✕ No |
| Progressive Loading | Yes | ✕ No |
| HDR Support | Yes | Yes |
| EXIF Metadata | Yes | Yes |
| ICC Color Profile | Yes | Yes |
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
Kodak Digital Camera Raw
image/x-kodak-dcr
Extension
.dcr
Container
TIFF/EP
Compression
Uncompressed / Lossless JPEG
Algorithm
NoneLossless JPEG (ITU-T81)
Color Depth
12-bit (Per Channel)
Developed by
Eastman Kodak Company
Released
1998
Magic Bytes
49 49 2A 00 or 4D 4D 00 2A
Browser Support Comparison
| Browser | JPX | Kodak-DCR |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
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
Kodak-DCR
Kodak-DCR Strengths
- Preserves the full dynamic range and uncompressed raw sensor data captured by foundational professional digital cameras
- Utilizes the standard TIFF container structure, ensuring that open-source decoders like LibRaw can easily parse and interpret the files long after official vendor support has ended
Limitations
- Completely obsolete proprietary format tied to camera hardware that is no longer manufactured
- Shares the TIFF magic header, leading to widespread misidentification by automated MIME detection libraries
- Cannot be natively viewed in web browsers or standard operating system image viewers without specialized codecs
When to choose which format
JPX
Use JPX when…
- Prepress & Commercial Printing (CMYK)
- Geospatial Data
- Archival Preservation
- Medical Imaging
Kodak-DCR
Use Kodak-DCR when…
- Vintage Professional Digital Photography (Kodak DCS series)
- Non-destructive Image Post-Processing
- Raw Imaging Archival