Image MIME Reference
DECE-Graphic
Digital Entertainment Content Ecosystem (DECE) Graphic
image/vnd.dece.graphic
VS
Windows Icon (Legacy MIME)
image/x-icon
ICO
A complete technical comparison of Digital Entertainment Content Ecosystem (DECE) Graphic and Windows Icon (Legacy MIME) — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
ICO wins on browser support
Feature Support
| Feature | DECE-Graphic | ICO |
|---|---|---|
| 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 |
Digital Entertainment Content Ecosystem (DECE) Graphic
image/vnd.dece.graphic
Extension
.jpg.png.uvi
Container
Standard JPEG/PNG within DECE CFF structures
Compression
Lossy (JPEG) / Lossless (PNG)
Algorithm
DCT (JPEG)DEFLATE (PNG)
Color Depth
8-bit (RGB), 24-bit (RGB)
Developed by
Digital Entertainment Content Ecosystem (DECE) LLC
Released
2011
Magic Bytes
FF D8 FF (If JPEG) / 89 50 4E 47 (If PNG)
Windows Icon (Legacy MIME)
image/x-icon
Extension
.ico
Container
ICO Directory Structure
Compression
Uncompressed (DIB/BMP) / Deflate (Embedded PNG)
Algorithm
NoneDeflate (via PNG)
Color Depth
1-bit, 4-bit, 8-bit, 24-bit (True Color), 32-bit (RGBA)
Developed by
Microsoft Corporation
Released
1985
Magic Bytes
00 00 01 00
Browser Support Comparison
| Browser | DECE-Graphic | ICO |
|---|---|---|
|
|
✕ |
✓ 1
|
|
|
✕ |
✓ 1
|
|
|
✕ |
✓ 1
|
|
|
✕ |
✓ 12
|
|
|
✕ |
✓
|
DECE-Graphic
DECE-Graphic Strengths
- Allowed the UltraViolet DRM ecosystem to easily distinguish structural UI/cover graphic assets from actual encrypted video tracks in a Common File Format container
Limitations
- Completely obsolete since the 2019 shutdown of UltraViolet
- Unnecessary abstraction, as the underlying files were just standard JPEGs or PNGs
- Causes modern strict MIME-type validators to fail if they rely on the Content-Type header
ICO
ICO Strengths
- Universally supported by every web browser in existence for website favicons
- Packs multiple resolutions into a single file, eliminating the need to serve different files for the taskbar vs. the desktop
- Modern support for embedded PNGs (since Windows Vista) allows for excellent 32-bit transparency (alpha channels) and drastically reduced file sizes
Limitations
- Internal file structure is convoluted due to decades of legacy cruft, such as the requirement for BMP data to lack a standard file header but double the height property for an archaic XOR/AND mask
- Larger file size compared to a single optimized PNG or SVG, as it literally stores the same image multiple times at different scales
- The MIME type landscape is highly fragmented (x-icon vs. vnd.microsoft.icon), causing occasional caching or strict-MIME validation errors on restrictive servers
When to choose which format
DECE-Graphic
Use DECE-Graphic when…
- UltraViolet Movie Cover Art
- Common File Format (CFF) Asset Manifests
- Legacy DRM Ecosystems
ICO
Use ICO when…
- Website Favicons (favicon.ico)
- Windows Application Executable Icons (.exe)
- Desktop Shortcut Icons