Image MIME Reference
DICOM-RLE
DICOM Run-Length Encoding
image/dicom-rle
VS
JPEG 2000 Core Image File
image/jp2
JPEG-2000
A complete technical comparison of DICOM Run-Length Encoding 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 | DICOM-RLE | JPEG-2000 |
|---|---|---|
| Transparency (Alpha) | ✕ No | Yes |
| Animation Support | Yes | ✕ No |
| Progressive Loading | ✕ No | Yes |
| HDR Support | Yes | Yes |
| EXIF Metadata | ✕ No | Yes |
| ICC Color Profile | Yes | Yes |
DICOM Run-Length Encoding
image/dicom-rle
Extension
.dcm.dicom
Container
DICOM (PS3.10)
Compression
Lossless (RLE)
Algorithm
Run-Length Encoding (RLE)
Color Depth
8-bit, 16-bit, 24-bit
Developed by
National Electrical Manufacturers Association (NEMA) / ACR
Released
1993
Magic Bytes
44 49 43 4D (at byte offset 128)
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 | DICOM-RLE | JPEG-2000 |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ |
✓ 5+
|
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
DICOM-RLE
DICOM-RLE Strengths
- Guarantees lossless preservation of critical medical data necessary for diagnostics
- Extremely robust metadata structure containing patient information, modality, and spatial geometry
- Faster to encode and decode than complex compression schemes like JPEG 2000
Limitations
- RLE compression offers very low compression ratios compared to modern codecs like JPEG-LS or JPEG 2000
- Zero support in web browsers or standard consumer image viewers
- Strict data privacy regulations (HIPAA/GDPR) make handling DICOM files complex due to embedded PHI
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
DICOM-RLE
Use DICOM-RLE when…
- Medical Imaging
- Ultrasound
- X-Rays / CT / MRI
- PACS Archives
JPEG-2000
Use JPEG-2000 when…
- Digital Cinema (DCP)
- Medical Imaging (DICOM)
- Geospatial Data
- Archival Preservation