Free webp to jpg
Image MIME Reference
FITS

Flexible Image Transport System

image/fits
VS

Apple PICT Image

image/x-pict
PICT

A complete technical comparison of Flexible Image Transport System and Apple PICT Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

Equal browser support

Feature Support

Feature FITS PICT
Transparency (Alpha) ✕ No Yes
Animation Support ✕ No ✕ No
Progressive Loading ✕ No ✕ No
HDR Support Yes ✕ No
EXIF Metadata ✕ No ✕ No
ICC Color Profile ✕ No ✕ No
Flexible Image Transport System
image/fits
Extension
.fits.fit.fts
Container FITS
Compression Uncompressed / Tile Compressed (Rice, GZIP)
Algorithm
UncompressedRiceGZIPHcompress
Color Depth 8-bit, 16-bit, 32-bit, 64-bit (Float/Double)
Developed by IAU FITS Working Group / NASA
Released 1981
Magic Bytes
53 49 4D 50 4C 45 20 20 3D 20
Full FITS reference →
Apple PICT Image
image/x-pict
Extension
.pict.pct.pic
Container QuickDraw Metafile
Compression Uncompressed / Run-Length Encoding (RLE) / QuickTime Compressors (JPEG, SMC)
Algorithm
Apple PackBits (RLE)QuickTime Image Compression Manager (ICM)
Color Depth 1-bit, 2-bit, 4-bit, 8-bit (Indexed), 16-bit (High Color), 24-bit (True Color), 32-bit (RGBA)
Developed by Apple Computer, Inc.
Released 1984
Magic Bytes
None (Requires offset parsing, e.g., 00 11 02 FF at byte 522)
Full PICT reference →

Browser Support Comparison

Browser FITS PICT
Chrome Chrome
Firefox Firefox
Safari Safari
Edge Edge
IE IE (Legacy)
FITS

FITS Strengths

  • The undisputed global standard for archiving and sharing astronomical data
  • Self-documenting: Headers are written in plain ASCII, ensuring data is readable decades later regardless of software
  • Supports incredibly high dynamic range, N-dimensional arrays, and complex binary tables
Limitations
  • No support in standard consumer software or web browsers
  • Uncompressed raw FITS files from modern telescopes can be excessively large
  • Does not use standard metadata models like EXIF or XMP, requiring specialized parsers
PICT

PICT Strengths

  • Incredibly versatile for its time, allowing a single file to cleanly scale text and vector shapes while simultaneously housing raster photos
  • Served as the flawless universal clipboard format for the classic Mac OS, enabling seamless copy/pasting between wildly different applications
Limitations
  • Deeply tied to Apple's legacy QuickDraw graphics architecture, making it exceptionally difficult to write accurate third-party parsers on modern operating systems
  • Lack of a standard magic header makes file detection unreliable without seeking 522 bytes deep into the file
  • Completely unsupported in modern web environments and discontinued by Apple itself

When to choose which format

FITS
Use FITS when…
  • Astronomy & Astrophysics
  • Space Telescope Data (Hubble, JWST)
  • Scientific Data Archiving
  • Spectroscopy
PICT
Use PICT when…
  • Classic Mac OS Clipboard Data
  • Legacy Macintosh Desktop Publishing (Aldus PageMaker, QuarkXPress)
  • 1980s/1990s Digital Clip Art
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