Image MIME Reference
EDMICS-RLC
Fuji Xerox EDMICS-RLC
image/vnd.fujixerox.edmics-rlc
VS
RealNetworks RealPix
image/vnd.rn-realpix
RealPix
A complete technical comparison of Fuji Xerox EDMICS-RLC and RealNetworks RealPix — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | EDMICS-RLC | RealPix |
|---|---|---|
| Transparency (Alpha) | ✕ No | Yes |
| Animation Support | ✕ No | Yes |
| Progressive Loading | ✕ No | Yes |
| 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)
RealNetworks RealPix
image/vnd.rn-realpix
Extension
.rp
Container
IMFL (XML Markup)
Compression
Uncompressed (Plain Text Markup)
Algorithm
None (Plain Text)
Color Depth
Dependent on referenced images
Developed by
RealNetworks
Released
1998
Magic Bytes
3C 69 6D 66 6C
Browser Support Comparison
| Browser | EDMICS-RLC | RealPix |
|---|---|---|
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
RealPix
RealPix Strengths
- Allowed for 'Ken Burns'-style animated slideshows at a fraction of the bandwidth required for actual video, crucial for 1990s dial-up connections
- Plain text XML architecture made it easy for developers and hobbyists to hand-code complex multimedia presentations
- Perfectly synchronized with RealAudio streams using SMIL-like timing parameters
Limitations
- Completely obsolete and heavily reliant on the proprietary, defunct RealPlayer browser plugin
- Not a true image format, causing confusion when handled by standard image processing libraries which expect binary pixel data
- Lacks modern CSS or HTML5 canvas equivalents without completely rewriting the presentation logic
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
RealPix
Use RealPix when…
- Historical Dial-up Streaming Presentations
- RealPlayer Slideshows
- Bandwidth-efficient 'Video' Alternatives (late 1990s)