Image MIME Reference
DECE-Graphic
Digital Entertainment Content Ecosystem (DECE) Graphic
image/vnd.dece.graphic
VS
Portable Graymap
image/x-portable-graymap
PGM
A complete technical comparison of Digital Entertainment Content Ecosystem (DECE) Graphic and Portable Graymap — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | DECE-Graphic | PGM |
|---|---|---|
| Transparency (Alpha) | Yes | ✕ No |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | ✕ No | Yes |
| 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)
Portable Graymap
image/x-portable-graymap
Extension
.pgm
Container
Netpbm
Compression
Uncompressed
Algorithm
None
Color Depth
8-bit (Grayscale), 16-bit (Grayscale)
Developed by
Jef Poskanzer (Netpbm Project)
Released
1988
Magic Bytes
50 32 (ASCII) or 50 35 (Binary)
Browser Support Comparison
| Browser | DECE-Graphic | PGM |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
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
PGM
PGM Strengths
- Extremely simple format allows custom parsers to be written from scratch in minimal time
- Supports 16-bit precision, making it highly valuable for scientific, medical, and height-map data where 8-bit precision is insufficient
- ASCII encoding ('P2') allows manual editing and visual inspection of pixel values directly within a text editor
Limitations
- Strictly limited to grayscale; cannot display color
- Lack of compression results in massive file sizes, making it entirely impractical for web delivery or consumer storage
- Does not support alpha transparency or modern metadata structures
When to choose which format
DECE-Graphic
Use DECE-Graphic when…
- UltraViolet Movie Cover Art
- Common File Format (CFF) Asset Manifests
- Legacy DRM Ecosystems
PGM
Use PGM when…
- Computer Vision and Machine Learning Pre-processing
- Scientific and Medical Image Processing
- Unix/Linux Command-Line Image Pipelines