Image MIME Reference
FITS
Flexible Image Transport System
image/fits
VS
Pixologic ZBrush PCX
image/vnd.zbrush.pcx
ZBrush-PCX
A complete technical comparison of Flexible Image Transport System and Pixologic ZBrush PCX — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | FITS | ZBrush-PCX |
|---|---|---|
| Transparency (Alpha) | ✕ No | ✕ No |
| 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
Pixologic ZBrush PCX
image/vnd.zbrush.pcx
Extension
.pcx
Container
ZSoft PCX
Compression
Run-Length Encoding (RLE)
Algorithm
ZSoft Run-Length Encoding (RLE)
Color Depth
8-bit (Grayscale), 24-bit (RGB)
Developed by
ZSoft (Format) / Pixologic (MIME Registration)
Released
1985
Magic Bytes
0A 05 01 08
Browser Support Comparison
| Browser | FITS | ZBrush-PCX |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
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
ZBrush-PCX
ZBrush-PCX Strengths
- Extremely simple, lossless RLE compression makes it trivial to parse and encode programmatically
- Universally supported by almost every 2D image editor created since the 1990s
Limitations
- Completely obsolete for modern 3D workflows, which require 16-bit or 32-bit floating-point precision (like OpenEXR or TIFF) to avoid stepping artifacts in displacement maps
- No support for modern metadata (EXIF/XMP) or native alpha channels
- Zero native support in modern web browsers
When to choose which format
FITS
Use FITS when…
- Astronomy & Astrophysics
- Space Telescope Data (Hubble, JWST)
- Scientific Data Archiving
- Spectroscopy
ZBrush-PCX
Use ZBrush-PCX when…
- Legacy ZBrush Alpha Brushes
- 8-bit Grayscale Displacement Maps
- ZBrush Texture Exports