Image MIME Reference
EDMICS-RLC
Fuji Xerox EDMICS-RLC
image/vnd.fujixerox.edmics-rlc
VS
Silicon Graphics Image
image/x-rgb
SGI-RGB
A complete technical comparison of Fuji Xerox EDMICS-RLC and Silicon Graphics Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | EDMICS-RLC | SGI-RGB |
|---|---|---|
| Transparency (Alpha) | ✕ No | Yes |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | ✕ No | ✕ No |
| EXIF Metadata | ✕ No | ✕ No |
| ICC Color Profile | ✕ No | ✕ No |
Fuji Xerox EDMICS-RLC
image/vnd.fujixerox.edmics-rlc
Extension
.rlc.edm
Container
Fuji Xerox EDMICS Wrapper
Compression
Run-Length Coding (RLC / RLE)
Algorithm
Run-Length Coding (RLC)
Color Depth
1-bit (Monochrome), 8-bit (Grayscale)
Developed by
Fuji Xerox Co., Ltd.
Released
1990s
Magic Bytes
Unknown (Proprietary Container)
Silicon Graphics Image
image/x-rgb
Extension
.rgb.sgi.rgba.bw.int.inta
Container
SGI Image Header (512 bytes)
Compression
Uncompressed / Run-Length Encoding (RLE)
Algorithm
NoneScanline RLE
Color Depth
8-bit (Per Channel), 16-bit (Per Channel)
Developed by
Silicon Graphics, Inc. (Paul Haeberli)
Released
1988
Magic Bytes
01 DA
Browser Support Comparison
| Browser | EDMICS-RLC | SGI-RGB |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
EDMICS-RLC
EDMICS-RLC Strengths
- Simple, computationally inexpensive Run-Length Coding enabled rapid compression and decompression on low-power legacy hardware
- Deeply integrated into Fuji Xerox enterprise hardware for seamless, automated scan-to-archive workflows
Limitations
- Completely proprietary and closed-source, making modern archival extraction and migration extremely difficult
- No support in modern image processing libraries like ImageMagick, libvips, or standard viewers without bespoke decoding tools
- RLC compression is far less efficient than modern algorithms like PNG (Deflate) for complex documents
SGI-RGB
SGI-RGB Strengths
- Supports 16-bit precision per channel and an embedded alpha channel, making it ideal for the demanding compositing workflows of 1990s cinema VFX
- The scanline-based RLE compression was exceptionally fast to decode on classic MIPS-based SGI workstations
- Features a straightforward 512-byte header, making it relatively easy to parse and write custom decoders in C or Python
Limitations
- Completely obsolete and unsupported in modern web environments
- Replaced entirely by TIFF, OpenEXR, and PNG in modern visual effects and 3D rendering pipelines
- Lacks support for modern color management via ICC profiles or advanced EXIF metadata
When to choose which format
EDMICS-RLC
Use EDMICS-RLC when…
- Fuji Xerox EDMICS Enterprise Systems
- Archival of Scanned Engineering Documents
- Legacy Corporate Scanning Pipelines
SGI-RGB
Use SGI-RGB when…
- Legacy 3D Animation and VFX Textures
- Silicon Graphics IRIX Workstation Archival
- 1990s Medical Imaging