Free webp to jpg
Image MIME Reference
HTJ2K-(JPH)

High-Throughput JPEG 2000 Image

image/jph
VS

SealedMedia SoftSeal JPEG

image/vnd.sealedmedia.softseal.jpg
SoftSeal-JPEG

A complete technical comparison of High-Throughput JPEG 2000 Image and SealedMedia SoftSeal JPEG — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

Equal browser support

Feature Support

Feature HTJ2K-(JPH) SoftSeal-JPEG
Transparency (Alpha) Yes ✕ No
Animation Support ✕ No ✕ No
Progressive Loading Yes ✕ No
HDR Support Yes ✕ No
EXIF Metadata Yes ✕ No
ICC Color Profile Yes ✕ No
High-Throughput JPEG 2000 Image
image/jph
Extension
.jph
Container JPH (ISO/IEC 15444-15)
Compression Lossy / Lossless
Algorithm
High-Throughput JPEG 2000 (HTJ2K)
Color Depth 8-bit, 16-bit, 32-bit, 38-bit
Developed by Joint Photographic Experts Group (JPEG)
Released 2019
Magic Bytes
00 00 00 0C 6A 50 20 20 0D 0A 87 0A ... 66 74 79 70 6A 70 68 20
Full HTJ2K-(JPH) reference →
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)
Full SoftSeal-JPEG reference →

Browser Support Comparison

Browser HTJ2K-(JPH) SoftSeal-JPEG
Chrome Chrome
Firefox Firefox
Safari Safari
Edge Edge
IE IE (Legacy)
HTJ2K-(JPH)

HTJ2K-(JPH) Strengths

  • Delivers orders of magnitude faster encoding and decoding than standard JPEG 2000 by utilizing a new, parallelizable block coder
  • Supports mathematically lossless and lossy compression within the same codestream architecture
  • Allows for resolution scalability, progressive decoding, and region-of-interest extraction without needing to decode the entire image
Limitations
  • Zero native web browser support, requiring specialized libraries, API conversions, or WebAssembly (like OpenJPH.js) for web deployment
  • Lack of broad consumer awareness, keeping it confined to professional, medical, and scientific workflows
  • Requires more advanced software ecosystems to decode than ubiquitous formats like JPEG or WebP
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

When to choose which format

HTJ2K-(JPH)
Use HTJ2K-(JPH) when…
  • Medical Imaging (DICOM)
  • Geospatial Data
  • Digital Cinema
  • Professional Archiving
SoftSeal-JPEG
Use SoftSeal-JPEG when…
  • Enterprise Information Rights Management (IRM)
  • Secure Distribution of Sensitive Photography
  • Revocable Corporate Document Access
Share this comparison