Free webp to jpg
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Image MIME Reference
Sealed-PNG

SealedMedia Portable Network Graphics

image/vnd.sealed.png
VS

TIFF for Facsimile eXtended

image/tiff-fx
TIFF-FX

A complete technical comparison of SealedMedia Portable Network Graphics and TIFF for Facsimile eXtended — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

Equal browser support

Feature Support

Feature Sealed-PNG TIFF-FX
Transparency (Alpha) ✕ No ✕ No
Animation Support ✕ No ✕ No
Progressive Loading ✕ No ✕ No
HDR Support ✕ No ✕ No
EXIF Metadata ✕ No ✕ No
ICC Color Profile ✕ No Yes
SealedMedia Portable Network Graphics
image/vnd.sealed.png
Extension
.spng.sealed-png
Container SealedMedia / Oracle IRM Wrapper
Compression Encrypted Payload (Deflate)
Algorithm
AES EncryptionDeflate (Internal PNG payload)
Color Depth Encrypted Payload
Developed by SealedMedia (Acquired by Oracle Corporation)
Released Late 1990s / Early 2000s
Magic Bytes
Unknown (Proprietary SealedMedia Container)
Full Sealed-PNG reference →
TIFF for Facsimile eXtended
image/tiff-fx
Extension
.tiff.tif
Container TIFF 6.0 Tag Directory Structure
Compression MH / MR / MMR (CCITT Group 3 & 4) / JBIG / JPEG
Algorithm
CCITT Group 3/4JBIGJPEG
Color Depth 1-bit (Monochrome B&W), 8-bit (Grayscale/Color Indexed), 24-bit (RGB Color)
Developed by IETF (Internet Engineering Task Force)
Released 1998
Magic Bytes
49 49 2A 00 (Little-Endian) / 4D 4D 00 2A (Big-Endian)
Full TIFF-FX reference →

Browser Support Comparison

Browser Sealed-PNG TIFF-FX
Chrome Chrome
✕ ✕
Firefox Firefox
✕ ✕
Safari Safari
✕ ✕
Edge Edge
✕ ✕
IE IE (Legacy)
✕ ✕
Sealed-PNG

Sealed-PNG Strengths

  • Provided absolute control over intellectual property, allowing enterprise administrators to instantly revoke viewing rights of a local file globally
  • Detailed audit trails tracked exactly who opened the image, when, and from what IP address
Limitations
  • Completely proprietary and relies on a central authentication server; if the server goes offline, the image is permanently inaccessible
  • No support in modern operating systems, web browsers, or standard image editing software without installing heavy enterprise DRM clients
  • Oracle effectively deprecated the IRM product line, leaving legacy sealed documents difficult to recover
TIFF-FX

TIFF-FX Strengths

  • Provides a universal, standardized format for transmitting multi-page documents over IP networks and email (Internet Fax)
  • Supports highly efficient telecom-centric compression algorithms (MMR, JBIG) that produce very small files for text documents
  • Maintains backwards compatibility with standard TIFF parsers
Limitations
  • Not supported natively by web browsers
  • Requires complex parsing of TIFF IFD tags to differentiate a true TIFF-FX file from a standard TIFF file
  • Usage is slowly declining as traditional faxing is replaced by secure PDF transmission and e-signature platforms

When to choose which format

Sealed-PNG
Use Sealed-PNG when…
  • Enterprise Information Rights Management (IRM)
  • Secure Corporate Intellectual Property Distribution
  • Revocable Medical or Legal Imaging
TIFF-FX
Use TIFF-FX when…
  • Internet Fax (T.37)
  • Enterprise Fax Servers
  • Document Archiving
  • Telecommunications

More comparisons

Sealed-PNG vs ACES → TIFF-FX vs ACES → Sealed-PNG vs APNG → TIFF-FX vs APNG → Sealed-PNG vs AVCI → TIFF-FX vs AVCI → Sealed-PNG vs AVCS → TIFF-FX vs AVCS → Sealed-PNG vs AVIF → TIFF-FX vs AVIF → All comparisons →
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