Image MIME Reference
FPX
FlashPix
image/vnd.fpx
VS
SealedMedia SoftSeal GIF
image/vnd.sealedmedia.softseal.gif
SoftSeal-GIF
A complete technical comparison of FlashPix and SealedMedia SoftSeal GIF — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | FPX | SoftSeal-GIF |
|---|---|---|
| Transparency (Alpha) | Yes | ✕ No |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | ✕ No | ✕ No |
| EXIF Metadata | Yes | ✕ No |
| ICC Color Profile | Yes | ✕ No |
FlashPix
image/vnd.fpx
Extension
.fpx
Container
Microsoft OLE Structured Storage (COM)
Compression
JPEG (Lossy) / Uncompressed / Single-color (Solid)
Algorithm
JPEGNone
Color Depth
8-bit (Grayscale/Indexed), 24-bit (RGB), 32-bit (CMYK/RGBA)
Developed by
Eastman Kodak, Microsoft, Hewlett-Packard, Live Picture
Released
1996
Magic Bytes
D0 CF 11 E0 A1 B1 1A E1
SealedMedia SoftSeal GIF
image/vnd.sealedmedia.softseal.gif
Extension
.sgif.sealed-gif
Container
SealedMedia SoftSeal Wrapper
Compression
Encrypted Payload (LZW)
Algorithm
AES EncryptionLZW (Internal GIF payload)
Color Depth
Encrypted Payload (Historically up to 8-bit Indexed)
Developed by
SealedMedia (Acquired by Oracle Corporation)
Released
Late 1990s
Magic Bytes
Unknown (Proprietary SealedMedia Container)
Browser Support Comparison
| Browser | FPX | SoftSeal-GIF |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
FPX
FPX Strengths
- Allowed early, low-RAM computers to view and edit massive, high-resolution digital photos instantly by only loading the needed tiles and resolutions
- Pioneered the multi-resolution pyramid and tiling concepts heavily used today in modern deep-zoom and web mapping applications (like Google Maps)
Limitations
- Completely obsolete and unsupported by modern web browsers or operating systems
- Uses the complex, proprietary Microsoft OLE container format, making it incredibly difficult to parse or extract data from without dedicated legacy libraries
- Prone to being misidentified by MIME sniffers as an old Microsoft Office document
SoftSeal-GIF
SoftSeal-GIF Strengths
- Provided robust, persistent security that traveled with the file, ensuring images could not be leaked even if sent outside the corporate firewall
- Enabled dynamic revocation, meaning administrators could instantly kill access to a file globally
Limitations
- Completely proprietary and dependent on an active authentication server; if the DRM server dies, the image is permanently locked
- Zero support in modern operating systems, web browsers, or standard image editing suites without heavy enterprise client installations
- Often caused massive friction for legitimate end-users trying to view documents
When to choose which format
FPX
Use FPX when…
- Legacy Digital Photography
- Kodak Picture CDs (Historical)
- Early High-Resolution Image Viewers
SoftSeal-GIF
Use SoftSeal-GIF when…
- Enterprise Information Rights Management (IRM)
- Secure Distribution of Corporate Assets
- Revocable Medical, Legal, or Financial Imaging