Free webp to jpg
Image MIME Reference
FST-Image

FAST Search & Transfer Image

image/vnd.fst
VS

High-Throughput JPEG 2000 Image

image/jph
HTJ2K-(JPH)

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

Equal browser support

Feature Support

Feature FST-Image HTJ2K-(JPH)
Transparency (Alpha) ✕ No Yes
Animation Support ✕ No ✕ No
Progressive Loading ✕ No Yes
HDR Support ✕ No Yes
EXIF Metadata ✕ No Yes
ICC Color Profile ✕ No Yes
FAST Search & Transfer Image
image/vnd.fst
Extension
.fst
Container Proprietary FAST Container
Compression Proprietary
Algorithm
Unknown (Proprietary FAST encoding)
Color Depth Unknown
Developed by FAST Search & Transfer ASA (Arild Fuldseth)
Released 2000
Magic Bytes
Unknown (Proprietary)
Full FST-Image reference →
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 →

Browser Support Comparison

Browser FST-Image HTJ2K-(JPH)
Chrome Chrome
Firefox Firefox
Safari Safari
Edge Edge
IE IE (Legacy)
FST-Image

FST-Image Strengths

  • Historically served as an optimized, compressed format for FAST's early multimedia and live streaming engines over constrained late-1990s bandwidth
Limitations
  • Completely obsolete and non-functional in modern software ecosystems
  • Undocumented, closed-source binary structure with zero support in modern image processing libraries
  • Shares its file extension with several other distinct file types (such as FL Studio state files or FAST Search dictionaries), leading to easy misidentification
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

When to choose which format

FST-Image
Use FST-Image when…
  • Historical FAST Enterprise Search Indexing
  • Legacy Proprietary Multimedia Streaming (late 1990s)
  • Internal Media Transmission
HTJ2K-(JPH)
Use HTJ2K-(JPH) when…
  • Medical Imaging (DICOM)
  • Geospatial Data
  • Digital Cinema
  • Professional Archiving
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