Image MIME Reference
SGI-RGB
Silicon Graphics Image
image/x-rgb
VS
Tencent TAP Image
image/vnd.tencent.tap
Tencent-TAP
A complete technical comparison of Silicon Graphics Image and Tencent TAP Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | SGI-RGB | Tencent-TAP |
|---|---|---|
| Transparency (Alpha) | Yes | ✕ No |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | ✕ No | ✕ No |
| EXIF Metadata | ✕ No | ✕ No |
| ICC Color Profile | ✕ No | ✕ No |
Silicon Graphics Image
image/x-rgb
Extension
.rgb.sgi.rgba.bw.int.inta
Container
SGI Image Header (512 bytes)
Compression
Uncompressed / Run-Length Encoding (RLE)
Algorithm
NoneScanline RLE
Color Depth
8-bit (Per Channel), 16-bit (Per Channel)
Developed by
Silicon Graphics, Inc. (Paul Haeberli)
Released
1988
Magic Bytes
01 DA
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 | SGI-RGB | Tencent-TAP |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
SGI-RGB
SGI-RGB Strengths
- Supports 16-bit precision per channel and an embedded alpha channel, making it ideal for the demanding compositing workflows of 1990s cinema VFX
- The scanline-based RLE compression was exceptionally fast to decode on classic MIPS-based SGI workstations
- Features a straightforward 512-byte header, making it relatively easy to parse and write custom decoders in C or Python
Limitations
- Completely obsolete and unsupported in modern web environments
- Replaced entirely by TIFF, OpenEXR, and PNG in modern visual effects and 3D rendering pipelines
- Lacks support for modern color management via ICC profiles or advanced EXIF metadata
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
SGI-RGB
Use SGI-RGB when…
- Legacy 3D Animation and VFX Textures
- Silicon Graphics IRIX Workstation Archival
- 1990s Medical Imaging
Tencent-TAP
Use Tencent-TAP when…
- Internal Tencent Ecosystem Applications
- Proprietary Mobile or Gaming Assets