Image MIME Reference
AOL-ART
AOL ART Image
image/x-jg
VS
AutoCAD Slide
image/vnd.sld
SLD
A complete technical comparison of AOL ART Image and AutoCAD Slide — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | AOL-ART | SLD |
|---|---|---|
| Transparency (Alpha) | ✕ No | ✕ No |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | Yes | ✕ No |
| HDR Support | ✕ No | ✕ No |
| EXIF Metadata | ✕ No | ✕ No |
| ICC Color Profile | ✕ No | ✕ No |
AOL ART Image
image/x-jg
Extension
.art
Container
Johnson-Grace Proprietary
Compression
Proprietary Wavelet (Photos) / Proprietary Palette-based (Graphics)
Algorithm
Wavelet (similar to early JPEG 2000 concepts)Lossy DCT
Color Depth
8-bit (Indexed), 24-bit (RGB)
Developed by
Johnson-Grace Company (Acquired by AOL)
Released
1994
Magic Bytes
4A 47 03 00 or 4A 47 04 00
AutoCAD Slide
image/vnd.sld
Extension
.sld
Container
AutoCAD Slide Container
Compression
Uncompressed (Vector Instructions)
Algorithm
None
Color Depth
8-bit (AutoCAD Indexed Color)
Developed by
Autodesk, Inc.
Released
1980s
Magic Bytes
41 75 74 6F 43 41 44 20 53 6C 69 64 65 0D 0A 1A 00
Browser Support Comparison
| Browser | AOL-ART | SLD |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
AOL-ART
AOL-ART Strengths
- Historically provided massive file size reductions (up to 3x smaller than JPEGs of the era) and highly optimized progressive rendering for 14.4k modems
- Enabled faster web browsing on the AOL network during the early days of the commercial internet
Limitations
- Completely proprietary, heavily patent-encumbered, and never officially reverse-engineered for the open-source community
- On-the-fly proxy compression ruined the visual fidelity of many 1990s websites for AOL users
- Virtually impossible to open on modern operating systems without installing niche, legacy image viewers
SLD
SLD Strengths
- Allowed for instantaneous loading of highly complex architectural and engineering blueprints on low-memory MS-DOS systems
- Easy-to-parse binary structure containing simple opcodes for drawing vectors and polygons
Limitations
- Completely obsolete and heavily fragmented, largely replaced by PDF and lightweight web-based DXF viewers
- Destructive 'snapshot' format irrevocably strips all useful, editable CAD geometry data from the original drawing
- Zero support in web browsers or standard image processing libraries
When to choose which format
AOL-ART
Use AOL-ART when…
- Historical AOL Dial-up Web Browsing
- Legacy America Online Client Assets
- 1990s Internet Archival
SLD
Use SLD when…
- Legacy AutoCAD Slideshows
- AutoCAD Custom Icon Menus
- Historical CAD Archival