Free webp to jpg
Image MIME Reference
FreeHand

Macromedia FreeHand Document

image/x-freehand
VS

High-Throughput JPEG 2000 Codestream

image/jphc
HTJ2K-Codestream

A complete technical comparison of Macromedia FreeHand Document and High-Throughput JPEG 2000 Codestream — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

Equal browser support

Feature Support

Feature FreeHand HTJ2K-Codestream
Transparency (Alpha) Yes Yes
Animation Support Yes ✕ No
Progressive Loading ✕ No Yes
HDR Support ✕ No Yes
EXIF Metadata ✕ No ✕ No
ICC Color Profile Yes ✕ No
Macromedia FreeHand Document
image/x-freehand
Extension
.fh.fh4.fh5.fh7.fh8.fh9.fh10.fh11.ft11
Container Proprietary Binary (Aldus Graphic Document)
Compression Uncompressed / Deflate (in later versions)
Algorithm
NoneDeflate (Optional in later versions)
Color Depth Vector Data (RGB/CMYK)
Developed by Altsys / Aldus / Macromedia
Released 1988
Magic Bytes
41 47 44 31 to 41 47 44 34
Full FreeHand reference →
High-Throughput JPEG 2000 Codestream
image/jphc
Extension
.jhc
Container None (Raw Codestream)
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
FF 4F FF 51
Full HTJ2K-Codestream reference →

Browser Support Comparison

Browser FreeHand HTJ2K-Codestream
Chrome Chrome
Firefox Firefox
Safari Safari
Edge Edge
IE IE (Legacy)
FreeHand

FreeHand Strengths

  • Historically one of the most powerful and intuitive vector editors on the market, praised for multi-page support long before Adobe Illustrator implemented it
  • Files are generally compact and self-contained
Limitations
  • Completely abandoned proprietary format; Adobe actively blocked native import in modern versions of Illustrator
  • No support in modern web browsers; must be converted to SVG
  • Versioning fragmentation means parsers must account for wildly different binary structures depending on the specific .fhX extension used
HTJ2K-Codestream

HTJ2K-Codestream Strengths

  • Extremely fast encoding and decoding capabilities due to the parallelizable block coder
  • Minimal file overhead since it lacks container headers and metadata
  • Ideal for streaming applications or embedded systems where parsing a full container is unnecessary
Limitations
  • Lacks standard metadata support (like EXIF, XMP, or ICC color profiles) since there is no container structure
  • Zero native web browser compatibility
  • Difficult to distinguish from standard JPEG 2000 codestreams without deeply parsing the internal marker segments

When to choose which format

FreeHand
Use FreeHand when…
  • Legacy Graphic Design Portfolios
  • Historical Desktop Publishing Archival
  • Old Corporate Logo Vectors
HTJ2K-Codestream
Use HTJ2K-Codestream when…
  • Medical Imaging Pipelines
  • Geospatial Data Streaming
  • Digital Cinema
  • Embedded Systems
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