Image MIME Reference
Canon-CR2
Canon Raw Version 2
image/x-canon-cr2
VS
Sony SRF Raw Image
image/x-sony-srf
Sony-SRF
A complete technical comparison of Canon Raw Version 2 and Sony SRF Raw Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | Canon-CR2 | Sony-SRF |
|---|---|---|
| Transparency (Alpha) | ✕ No | ✕ No |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | Yes | Yes |
| EXIF Metadata | Yes | Yes |
| ICC Color Profile | Yes | Yes |
Canon Raw Version 2
image/x-canon-cr2
Extension
.cr2
Container
TIFF
Compression
Lossless JPEG (ITU-T81)
Algorithm
Lossless JPEG (ITU-T81)
Color Depth
12-bit (Per Channel), 14-bit (Per Channel)
Developed by
Canon Inc.
Released
2004
Magic Bytes
49 49 2A 00 10 00 00 00 43 52 02 00
Sony SRF Raw Image
image/x-sony-srf
Extension
.srf
Container
TIFF-based (Proprietary)
Compression
Uncompressed
Algorithm
None
Color Depth
12-bit (Per Channel)
Developed by
Sony Corporation
Released
2003
Magic Bytes
49 49 2A 00
Browser Support Comparison
| Browser | Canon-CR2 | Sony-SRF |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
Canon-CR2
Canon-CR2 Strengths
- Retains maximum sensor data, allowing extreme recovery of highlights and shadows that would be permanently lost in a JPEG
- White balance and color profiling are not 'baked in', meaning they can be completely altered in post-production without degrading the image
- Lossless compression ensures perfect pixel accuracy while reducing file size compared to fully uncompressed formats
Limitations
- Proprietary format means it requires constant updates to raw processing engines (like Adobe Camera Raw) every time Canon releases a new camera model
- Produces very large file sizes (often 20MB to 40MB per image depending on sensor resolution)
- Cannot be directly embedded into web pages or used in standard HTML/CSS contexts
Sony-SRF
Sony-SRF Strengths
- Retains perfectly raw, unprocessed sensor data from legacy early-2000s cameras, allowing modern raw processors to extract much better dynamic range and color than the camera's original internal JPEG engine could
- Utilizes a standard TIFF container structure, ensuring broad compatibility with community-maintained open-source decoding libraries like LibRaw
Limitations
- Completely obsolete format that has long been abandoned in favor of ARW
- MIME detection via magic bytes is unreliable due to TIFF header spoofing, requiring deeper EXIF inspection for accurate routing
- Cannot be natively viewed in web browsers or standard operating system image viewers without specialized decoders
When to choose which format
Canon-CR2
Use Canon-CR2 when…
- Professional Digital Photography
- Non-destructive Image Post-Processing
- High Dynamic Range (HDR) Imaging Archival
Sony-SRF
Use Sony-SRF when…
- Legacy Sony Cyber-shot Photography
- Non-destructive Image Post-Processing
- Early 2000s Raw Imaging Archival