Image MIME Reference
QTIF
QuickTime Image Format
image/x-quicktime
VS
X Pixmap
image/x-xpixmap
XPM
A complete technical comparison of QuickTime Image Format and X Pixmap — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | QTIF | XPM |
|---|---|---|
| Transparency (Alpha) | Yes | Yes |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | ✕ No | ✕ No |
| EXIF Metadata | ✕ No | ✕ No |
| ICC Color Profile | ✕ No | ✕ No |
QuickTime Image Format
image/x-quicktime
Extension
.qtif.qti.qif
Container
QuickTime Atom Container
Compression
Varies (JPEG, SMC, Apple Video, Cinepak, Uncompressed)
Algorithm
QuickTime Image Compression Manager (ICM) Codecs
Color Depth
1-bit to 32-bit (Varies depending on the enclosed codec)
Developed by
Apple Computer, Inc.
Released
1991
Magic Bytes
Varies (Typically begins with a 32-bit size integer followed by 69 64 73 63 ('idsc'))
X Pixmap
image/x-xpixmap
Extension
.xpm
Container
C Source Code Header (.c / .h)
Compression
Uncompressed (Source Code)
Algorithm
None
Color Depth
Indexed Color (Custom Palette with RGB and Alpha 'None')
Developed by
Daniel Dardailler and Colas Nahaboo (Bull / X Consortium)
Released
1989
Magic Bytes
2F 2A 20 58 50 4D 20 2A 2F (ASCII '/* XPM */')
Browser Support Comparison
| Browser | QTIF | XPM |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ |
✓
|
QTIF
QTIF Strengths
- Extremely flexible architecture allowing it to encapsulate virtually any image compression algorithm available on the host machine
- Supported 32-bit images with alpha channels (transparency) long before PNG became an established standard
Limitations
- Fundamentally tied to Apple's deprecated QuickTime architecture, rendering the files almost entirely unreadable on modern systems without specialized legacy software or FFmpeg
- The 'wrapper' nature of the format means that even if a parser can read the QTIF container, it may fail to render the image if it lacks the specific proprietary codec (like Apple SMC) used to compress the pixel data
- Zero native support in modern web browsers
XPM
XPM Strengths
- Can be compiled directly into C or C++ source code without requiring an external asset loading mechanism
- Human-readable palette mapping allows developers to inspect, modify, or hand-craft icons directly within a text editor
- Native support for color palettes and transparency via the 'None' keyword
Limitations
- Extremely inefficient storage structure for large images, resulting in massive file bloat compared to binary formats like PNG
- Completely obsolete and unsupported in modern web browsers
- Parsing overhead requires compiling or interpreting text-based color tables at runtime
When to choose which format
QTIF
Use QTIF when…
- Classic Mac OS Applications and Backgrounds
- QuickTime VR Panorama Textures
- 1990s CD-ROM Multimedia Assets
XPM
Use XPM when…
- X Window System (X11) Application Icons and Cursors
- Embedded C/C++ Firmware Color UI Assets
- Early Linux Desktop Environment Themes