Image MIME Reference
Canon-CRW
Canon Raw Format
image/x-canon-crw
VS
Tencent TAP Image
image/vnd.tencent.tap
Tencent-TAP
A complete technical comparison of Canon Raw Format and Tencent TAP Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | Canon-CRW | Tencent-TAP |
|---|---|---|
| Transparency (Alpha) | ✕ No | ✕ No |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | Yes | ✕ No |
| EXIF Metadata | Yes | ✕ No |
| ICC Color Profile | ✕ No | ✕ No |
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)
Tencent TAP Image
image/vnd.tencent.tap
Extension
.tap
Container
Proprietary Tencent Container
Compression
Unknown (Proprietary)
Algorithm
Unknown
Color Depth
Unknown
Developed by
Tencent (Registered by Ni Hui)
Released
2014
Magic Bytes
Unknown (Proprietary)
Browser Support Comparison
| Browser | Canon-CRW | Tencent-TAP |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
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
Tencent-TAP
Tencent-TAP Strengths
- Officially registered with IANA, ensuring a unique MIME type identifier for internal Tencent network routing and content negotiation
Limitations
- Completely undocumented and closed-source, making it impossible to decode or parse outside of Tencent's software
- Shares its file extension (.tap) with numerous other established legacy formats, leading to frequent automated file misidentification by Node/Python libraries
When to choose which format
Canon-CRW
Use Canon-CRW when…
- Historical Digital Photography (2000-2004)
- Non-destructive Image Post-Processing
- Raw Imaging Archival
Tencent-TAP
Use Tencent-TAP when…
- Internal Tencent Ecosystem Applications
- Proprietary Mobile or Gaming Assets