Image MIME Reference
IEF
Image Exchange Format
image/ief
VS
JPEG 2000 Core Image File
image/jp2
JPEG-2000
A complete technical comparison of Image Exchange Format and JPEG 2000 Core Image File — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
JPEG-2000 wins on browser support
Feature Support
| Feature | IEF | JPEG-2000 |
|---|---|---|
| Transparency (Alpha) | ✕ No | Yes |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | Yes |
| HDR Support | ✕ No | Yes |
| EXIF Metadata | ✕ No | Yes |
| ICC Color Profile | ✕ No | Yes |
Image Exchange Format
image/ief
Extension
.ief
Container
TIFF Class B (TIFF-B)
Compression
Lossless (MH, MR, MMR) / Uncompressed
Algorithm
MHMRMMRUncompressed
Color Depth
1-bit (Monochrome)
Developed by
IETF Network Fax Working Group
Released
1992
Magic Bytes
49 49 2A 00 (Little-endian) / 4D 4D 00 2A (Big-endian)
JPEG 2000 Core Image File
image/jp2
Extension
.jp2.j2k.jpf.jpx.jpm
Container
JP2 (ISO/IEC 15444-1)
Compression
Lossy / Lossless
Algorithm
Discrete Wavelet Transform (DWT)
Color Depth
8-bit, 16-bit, 32-bit, 38-bit
Developed by
Joint Photographic Experts Group
Released
2000
Magic Bytes
00 00 00 0C 6A 50 20 20 0D 0A 87 0A
Browser Support Comparison
| Browser | IEF | JPEG-2000 |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ |
✓ 5+
|
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
IEF
IEF Strengths
- Provided a standard method for exchanging bi-level fax images during the early days of the Internet
- Supported multi-page documents
- Leveraged the highly resilient and well-documented TIFF container
Limitations
- Completely obsolete and unsupported in modern computing environments
- Strictly limited to 1-bit monochrome data, lacking color or grayscale capabilities
- Magic bytes overlap completely with standard TIFF, making specific filetype detection difficult without parsing internal tags
JPEG-2000
JPEG-2000 Strengths
- Superior compression efficiency over baseline JPEG without introducing blocking artifacts
- True mathematically lossless compression available in the same format
- Extremely scalable: a single file can be decoded at various resolutions (thumbnails to full size) without loading the entire file
Limitations
- Very poor native web browser support prevents it from being a web standard
- High computational complexity makes encoding and decoding significantly slower than JPEG
- Early patent concerns and complex licensing hindered its initial adoption rate
When to choose which format
IEF
Use IEF when…
- Legacy Fax Transmissions
- Early Internet Gateways
- Archival
JPEG-2000
Use JPEG-2000 when…
- Digital Cinema (DCP)
- Medical Imaging (DICOM)
- Geospatial Data
- Archival Preservation