Image MIME Reference
EDMICS-RLC
Fuji Xerox EDMICS-RLC
image/vnd.fujixerox.edmics-rlc
VS
Group 3 Fax Image
image/g3fax
G3-Fax
A complete technical comparison of Fuji Xerox EDMICS-RLC and Group 3 Fax Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | EDMICS-RLC | G3-Fax |
|---|---|---|
| Transparency (Alpha) | ✕ No | ✕ No |
| 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)
Group 3 Fax Image
image/g3fax
Extension
.g3
Container
Raw Bitstream
Compression
Lossless (CCITT Group 3)
Algorithm
CCITT Group 3 (Modified Huffman / READ)
Color Depth
1-bit (Monochrome)
Developed by
CCITT (now ITU-T) / IETF
Released
1980
Magic Bytes
None (Raw Bitstream)
Browser Support Comparison
| Browser | EDMICS-RLC | G3-Fax |
|---|---|---|
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
G3-Fax
G3-Fax Strengths
- Extremely efficient compression for 1-bit black-and-white text and line art
- Standardized via RFC 1494 for email and internet fax transmission
- Low bandwidth requirements
Limitations
- Raw format lacks metadata (such as image width and resolution), requiring out-of-band information to decode accurately
- Strictly limited to 1-bit monochrome imagery
- Zero native web browser support
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
G3-Fax
Use G3-Fax when…
- Telefacsimile (Fax) Transmission
- Internet Fax (T.37)
- Document Archiving
- Telephony Systems