Image MIME Reference
Epson-ERF
Epson Raw Format
image/x-epson-erf
VS
GIMP Image Format
image/x-xcf
XCF
A complete technical comparison of Epson Raw Format and GIMP Image Format — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | Epson-ERF | XCF |
|---|---|---|
| Transparency (Alpha) | ✕ No | Yes |
| Animation Support | ✕ No | Yes |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | Yes | Yes |
| EXIF Metadata | Yes | Yes |
| ICC Color Profile | ✕ No | Yes |
Epson Raw Format
image/x-epson-erf
Extension
.erf
Container
TIFF/EP
Compression
Uncompressed / Lossless JPEG (ITU-T81)
Algorithm
NoneLossless JPEG
Color Depth
12-bit (Per Channel)
Developed by
Seiko Epson Corporation
Released
2004
Magic Bytes
49 49 2A 00 or 4D 4D 00 2A
GIMP Image Format
image/x-xcf
Extension
.xcf
Container
GIMP Hierarchical Chunk Container
Compression
None / RLE (Run-Length Encoding) / Zlib / Deflate (In newer GIMP versions)
Algorithm
NoneRLEZlib
Color Depth
8-bit per channel, 16-bit per channel, 32-bit floating point
Developed by
Spencer Kimball, Peter Mattis, and the GIMP Development Team
Released
1995
Magic Bytes
67 69 6D 70 20 78 63 66
Browser Support Comparison
| Browser | Epson-ERF | XCF |
|---|---|---|
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✕ | ✕ |
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✕ | ✕ |
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✕ | ✕ |
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✕ | ✕ |
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✕ | ✕ |
Epson-ERF
Epson-ERF Strengths
- Preserves original raw sensor data, allowing extreme recovery of highlights and shadows compared to in-camera JPEGs
- Utilizes the standard TIFF container structure, making it relatively easy for open-source software (like dcraw and LibRaw) to parse and decode
Limitations
- Completely obsolete proprietary format tied to a defunct line of digital cameras
- Requires parsing EXIF metadata to differentiate it from standard TIFF files programmatically
- Cannot be natively viewed in web browsers or standard operating system image viewers without specialized codecs
XCF
XCF Strengths
- Preserves all non-destructive editing elements, layer hierarchies, masks, and alpha channels across GIMP sessions
- Open and thoroughly documented specification within the open-source community, allowing third-party tools like Krita and ImageMagick to read project files
- Reliable magic byte header prevents misidentification
Limitations
- Massive file sizes because raw, unflattened layer bitmaps and masks are stored directly within the project archive
- Completely proprietary to the GIMP ecosystem for deep editing; cannot be natively rendered or parsed by web browsers
- Third-party software supporting XCF may occasionally struggle to render complex text layer adjustments or advanced layer blend modes identically to GIMP
When to choose which format
Epson-ERF
Use Epson-ERF when…
- Vintage Digital Photography (Epson R-D1)
- Non-destructive Image Post-Processing
- Raw Imaging Archival
XCF
Use XCF when…
- GIMP Native Project Archival
- Layered Photo Editing and Graphic Design
- Intermediary Asset Preparation for Export