Image MIME Reference
Epson-ERF
Epson Raw Format
image/x-epson-erf
VS
JPEG XR Image (HEIF Container)
image/jxra
JPEG-XR-(HEIF)
A complete technical comparison of Epson Raw Format and JPEG XR Image (HEIF Container) — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | Epson-ERF | JPEG-XR-(HEIF) |
|---|---|---|
| Transparency (Alpha) | ✕ No | Yes |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | Yes |
| 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
JPEG XR Image (HEIF Container)
image/jxra
Extension
.jxra
Container
HEIF / ISOBMFF (ISO/IEC 23008-12 / Annex F of ITU-T T.832)
Compression
Lossy / Lossless
Algorithm
JPEG XR (Lapped Biorthogonal Transform)
Color Depth
8-bit, 16-bit, 32-bit (Float)
Developed by
ISO/IEC JTC 1 / ITU-T
Released
2019
Magic Bytes
XX XX XX XX 66 74 79 70 6A 78 72 41
Browser Support Comparison
| Browser | Epson-ERF | JPEG-XR-(HEIF) |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
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
JPEG-XR-(HEIF)
JPEG-XR-(HEIF) Strengths
- Combines the deep color (32-bit float) and mathematically lossless compression of JPEG XR with the robust metadata architecture of HEIF
- Allows grouping multiple images, exposure brackets, or focal stacks into a single file collection
Limitations
- Practically non-existent software and operating system support compared to standard HEIC or legacy JPEG XR (.jxr)
- Zero web browser support, rendering it entirely unsuitable for public web deployment
- Eclipsed by modern standards like AVIF and JPEG XL which offer superior compression with much broader industry backing
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
JPEG-XR-(HEIF)
Use JPEG-XR-(HEIF) when…
- Specialized Archival
- Experimental Imaging Workflows
- High Dynamic Range (HDR) Imaging