Image MIME Reference
Canon-CRW
Canon Raw Format
image/x-canon-crw
VS
JPEG Stereo Image
image/x-jps
JPS
A complete technical comparison of Canon Raw Format and JPEG Stereo Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
JPS wins on browser support
Feature Support
| Feature | Canon-CRW | JPS |
|---|---|---|
| Transparency (Alpha) | ✕ No | ✕ No |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | Yes |
| HDR Support | Yes | ✕ No |
| EXIF Metadata | Yes | Yes |
| ICC Color Profile | ✕ No | Yes |
Canon Raw Format
image/x-canon-crw
Extension
.crw
Container
CIFF (Camera Image File Format)
Compression
Lossless JPEG (ITU-T81)
Algorithm
Lossless JPEG
Color Depth
10-bit (Per Channel), 12-bit (Per Channel)
Developed by
Canon Inc.
Released
1998
Magic Bytes
49 49 1A 00 00 00 (Header) / 48 45 41 50 43 43 44 52 (HEAPCCDR signature near end)
JPEG Stereo Image
image/x-jps
Extension
.jps
Container
JPEG (JFIF/Exif)
Compression
Lossy (JPEG/DCT)
Algorithm
JPEG (Discrete Cosine Transform)
Color Depth
8-bit (Grayscale), 24-bit (RGB)
Developed by
Stereoscopic Community (Unofficial Standard)
Released
1990
Magic Bytes
FF D8 FF
Browser Support Comparison
| Browser | Canon-CRW | JPS |
|---|---|---|
Chrome
|
✕ |
✓ 1
|
Firefox
|
✕ |
✓ 1
|
Safari
|
✕ |
✓ 1
|
Edge
|
✕ |
✓ 12
|
IE (Legacy)
|
✕ |
✓
|
Canon-CRW
Canon-CRW Strengths
- Preserves original raw sensor data from foundational early digital SLR cameras, allowing for modern noise reduction and demosaicing algorithms to extract better images than software could in 2003
- Files are remarkably small (often 6-8 MB) compared to modern 40MB+ raw files due to the lower megapixel count of early sensors
Limitations
- Completely obsolete and utilizes the idiosyncratic CIFF structure rather than the modern, standardized TIFF/EP structure
- Cannot be natively viewed in web browsers or standard operating system image viewers without specialized codecs
- Less robust metadata support compared to modern CR2 or CR3 formats
JPS
JPS Strengths
- 100% backward compatible with every standard 2D image viewer and web browser (which simply display the two halves side-by-side)
- Inherits JPEG's excellent lossy compression, resulting in small file sizes ideal for web transmission
- Extremely easy to generate programmatically by simply stitching two JPEG images side-by-side onto a wider canvas
Limitations
- Lack of a dedicated metadata standard means viewing software has to guess whether the layout is 'cross-eyed' (right eye left, left eye right) or 'parallel' (left eye left, right eye right), occasionally causing inverted depth
- Suffers from JPEG compression artifacts, which can break the stereoscopic illusion if compression noise differs between the left and right eyes
- Superseded in consumer electronics by the MPO (Multi-Picture Object) format, which stacks separate full-resolution JPEGs rather than squishing them side-by-side
When to choose which format
Canon-CRW
Use Canon-CRW when…
- Historical Digital Photography (2000-2004)
- Non-destructive Image Post-Processing
- Raw Imaging Archival
JPS
Use JPS when…
- Stereoscopic 3D Photography
- Virtual Reality (VR) Image Galleries
- Cross-eye / Parallel Stereograms