Free webp to jpg
EN
Image MIME Reference
JPM

JPEG 2000 Compound Image File Format

image/jpm
VS

SealedMedia SoftSeal GIF

image/vnd.sealedmedia.softseal.gif
SoftSeal-GIF

A complete technical comparison of JPEG 2000 Compound Image File Format and SealedMedia SoftSeal GIF — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

Equal browser support

Feature Support

Feature JPM SoftSeal-GIF
Transparency (Alpha) Yes ✕ No
Animation Support ✕ No ✕ No
Progressive Loading Yes ✕ No
HDR Support ✕ No ✕ No
EXIF Metadata Yes ✕ No
ICC Color Profile Yes ✕ No
JPEG 2000 Compound Image File Format
image/jpm
Extension
.jpm.jpgm
Container ISOBMFF / JPM (ISO/IEC 15444-6)
Compression Lossy / Lossless / Mixed Raster Content (MRC)
Algorithm
JPEG 2000JBIG2JPEGMMR
Color Depth 1-bit (Text/Masks), 8-bit, 16-bit, 24-bit
Developed by Joint Photographic Experts Group (JPEG)
Released 2003
Magic Bytes
00 00 00 0C 6A 50 20 20 0D 0A 87 0A ... 66 74 79 70 6A 70 6D 20
Full JPM reference →
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)
Full SoftSeal-GIF reference →

Browser Support Comparison

Browser JPM SoftSeal-GIF
Chrome Chrome
✕ ✕
Firefox Firefox
✕ ✕
Safari Safari
✕ ✕
Edge Edge
✕ ✕
IE IE (Legacy)
✕ ✕
JPM

JPM Strengths

  • Highly optimized for scanned documents, drastically reducing file sizes without sacrificing the readability of text or the quality of embedded photos
  • Supports multi-page documents within a single file
  • Object-based architecture allows for complex layout representation and independent extraction of elements
Limitations
  • Failed to achieve widespread adoption, largely being overshadowed by PDF/A and DjVu
  • Zero native web browser compatibility
  • Requires complex, specialized software to properly encode and decode the multi-layered MRC structure
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

JPM
Use JPM when…
  • Scanned Document Archiving
  • Mixed Raster Content (MRC) Imaging
  • Digital Libraries
SoftSeal-GIF
Use SoftSeal-GIF when…
  • Enterprise Information Rights Management (IRM)
  • Secure Distribution of Corporate Assets
  • Revocable Medical, Legal, or Financial Imaging

More comparisons

JPM vs ACES → SoftSeal-GIF vs ACES → JPM vs APNG → SoftSeal-GIF vs APNG → JPM vs AVCI → SoftSeal-GIF vs AVCI → JPM vs AVCS → SoftSeal-GIF vs AVCS → JPM vs AVIF → SoftSeal-GIF vs AVIF → All comparisons →
Share this comparison