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

High-Throughput JPEG 2000 Image

image/jph
VS

Silicon Graphics Image

image/sgi
SGI

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

Equal browser support

Feature Support

Feature HTJ2K-(JPH) SGI
Transparency (Alpha) Yes Yes
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 →
Silicon Graphics Image
image/sgi
Extension
.sgi.rgb.rgba.bw.int.inta
Container SGI Image Format
Compression Uncompressed / Lossless (Run-Length Encoding)
Algorithm
RLENone
Color Depth 8-bit, 16-bit (Per Channel)
Developed by Paul Haeberli (Silicon Graphics)
Released 1990
Magic Bytes
01 DA
Full SGI reference →

Browser Support Comparison

Browser HTJ2K-(JPH) SGI
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
SGI

SGI Strengths

  • Pioneered multi-channel and 16-bit per channel imaging capabilities required for high-end 1990s visual effects
  • Extremely robust and simple header structure
  • Reliable Run-Length Encoding provided solid lossless compression for flat-shaded 3D renders
Limitations
  • Completely obsolete for modern web and application development
  • Zero native web browser compatibility
  • Largely replaced by TIFF and OpenEXR in modern professional VFX and 3D pipelines

When to choose which format

HTJ2K-(JPH)
Use HTJ2K-(JPH) when…
  • Medical Imaging (DICOM)
  • Geospatial Data
  • Digital Cinema
  • Professional Archiving
SGI
Use SGI when…
  • Legacy 3D Animation & VFX
  • Silicon Graphics IRIX Workflows
  • Historical CGI Archiving
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