Image MIME Reference
SoftSeal-JPEG
SealedMedia SoftSeal JPEG
image/vnd.sealedmedia.softseal.jpg
VS
Tencent TAP Image
image/vnd.tencent.tap
Tencent-TAP
A complete technical comparison of SealedMedia SoftSeal JPEG and Tencent TAP Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | SoftSeal-JPEG | Tencent-TAP |
|---|---|---|
| Transparency (Alpha) | ✕ No | ✕ No |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | ✕ No | ✕ No |
| EXIF Metadata | ✕ No | ✕ No |
| ICC Color Profile | ✕ No | ✕ No |
SealedMedia SoftSeal JPEG
image/vnd.sealedmedia.softseal.jpg
Extension
.sjpg.sealed-jpg.sealed-jpeg
Container
SealedMedia SoftSeal Wrapper
Compression
Encrypted Payload (DCT)
Algorithm
AES EncryptionDiscrete Cosine Transform (Internal JPEG payload)
Color Depth
Encrypted Payload (Historically 24-bit RGB)
Developed by
SealedMedia (Acquired by Oracle Corporation)
Released
Late 1990s
Magic Bytes
Unknown (Proprietary SealedMedia Container)
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 | SoftSeal-JPEG | Tencent-TAP |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
SoftSeal-JPEG
SoftSeal-JPEG Strengths
- Offered persistent document security; if a sensitive photo was emailed outside the company, it remained encrypted and unviewable without server authentication
- Administrators possessed the ability to remotely revoke viewing rights to a specific image globally at any time
Limitations
- Completely proprietary and relies on a central authentication server; if the server goes offline or the product is deprecated, the image is permanently inaccessible
- Zero support in modern operating systems, web browsers, or standard image editing suites without heavy enterprise client installations
- Oracle effectively discontinued the IRM product line, stranding many legacy sealed documents
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
SoftSeal-JPEG
Use SoftSeal-JPEG when…
- Enterprise Information Rights Management (IRM)
- Secure Distribution of Sensitive Photography
- Revocable Corporate Document Access
Tencent-TAP
Use Tencent-TAP when…
- Internal Tencent Ecosystem Applications
- Proprietary Mobile or Gaming Assets