Image MIME Reference
DICOM-RLE
DICOM Run-Length Encoding
image/dicom-rle
VS
Kodak KDC Raw Image
image/x-kodak-kdc
Kodak-KDC
A complete technical comparison of DICOM Run-Length Encoding and Kodak KDC Raw Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | DICOM-RLE | Kodak-KDC |
|---|---|---|
| Transparency (Alpha) | ✕ No | ✕ No |
| Animation Support | Yes | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| 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)
Kodak KDC Raw Image
image/x-kodak-kdc
Extension
.kdc
Container
TIFF/EP
Compression
Uncompressed / Proprietary Lossless
Algorithm
NoneLossless JPEG (ITU-T81)Proprietary Kodak Compression
Color Depth
10-bit, 12-bit (Per Channel)
Developed by
Eastman Kodak Company
Released
1995
Magic Bytes
49 49 2A 00 or 4D 4D 00 2A
Browser Support Comparison
| Browser | DICOM-RLE | Kodak-KDC |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
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
Kodak-KDC
Kodak-KDC Strengths
- Preserves original raw sensor data, allowing modern demosaicing software to extract significantly more detail and dynamic range than the camera's built-in JPEG engine could at the time
- Utilizes the standard TIFF container structure, ensuring broad compatibility with open-source decoding libraries (like LibRaw)
Limitations
- Completely obsolete proprietary format tied to a defunct line of consumer digital cameras
- Subject to widespread misidentification by automated MIME detection libraries due to structural similarities with standard TIFFs
- Cannot be natively viewed in web browsers or standard operating system image viewers without specialized decoders
When to choose which format
DICOM-RLE
Use DICOM-RLE when…
- Medical Imaging
- Ultrasound
- X-Rays / CT / MRI
- PACS Archives
Kodak-KDC
Use Kodak-KDC when…
- Vintage Digital Photography Archival
- Kodak DC and EasyShare P-Series Raw Post-Processing
- Historical Imaging Research