Image MIME Reference
MrSID
Multi-resolution Seamless Image Database
image/x-mrsid-image
VS
Radiance HDR
image/vnd.radiance
Radiance
A complete technical comparison of Multi-resolution Seamless Image Database and Radiance HDR — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | MrSID | Radiance |
|---|---|---|
| Transparency (Alpha) | Yes | ✕ No |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | Yes | ✕ No |
| HDR Support | ✕ No | Yes |
| EXIF Metadata | Yes | ✕ No |
| ICC Color Profile | Yes | ✕ No |
Multi-resolution Seamless Image Database
image/x-mrsid-image
Extension
.sid
Container
Proprietary MrSID Container
Compression
Proprietary Wavelet (Lossy) / Proprietary Wavelet (Lossless)
Algorithm
Discrete Wavelet Transform (DWT)
Color Depth
8-bit (Grayscale), 24-bit (RGB), Multi-spectral (Multiple bands)
Developed by
Los Alamos National Laboratory / LizardTech (Extensis)
Released
1992
Magic Bytes
6D 73 69 64
Radiance HDR
image/vnd.radiance
Extension
.hdr.pic.rgbe.xyze
Container
Radiance Information Header
Compression
Run-Length Encoding (RLE) / Uncompressed
Algorithm
Adaptive Run-Length Encoding (RLE)
Color Depth
32-bit (8-bit per channel RGB + 8-bit shared Exponent)
Developed by
Greg Ward (Lawrence Berkeley National Laboratory)
Released
1989
Magic Bytes
23 3F 52 41 44 49 41 4E 43 45
Browser Support Comparison
| Browser | MrSID | Radiance |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
MrSID
MrSID Strengths
- Incredible compression ratios enable multi-gigabyte geographical datasets to be stored on standard hard drives or transmitted easily
- Multi-resolution architecture means panning and zooming across a massive map is completely fluid, as the system decodes only the visible quadrant at the required zoom level
- Supports multi-spectral bands critical for remote sensing and agricultural GIS analysis
Limitations
- Deeply proprietary; creating or decoding MrSID files typically requires expensive commercial software or the proprietary Extensis DSDK
- Open-source geospatial libraries like GDAL require compiling against the proprietary SDK to legally enable MrSID support, causing licensing headaches for Linux server deployments
- Not natively viewable on the web without specialized geospatial map servers (like GeoServer or MapServer) tiling the image into PNGs or JPEGs on the fly
Radiance
Radiance Strengths
- Universally supported by almost every 3D modeling software, renderer, and game engine in existence
- RGBE encoding offers a brilliant balance between High Dynamic Range capability and small file size (compared to 32-bit float OpenEXR)
- Simple, easy-to-parse ASCII header followed by straightforward RLE binary data
Limitations
- Does not support alpha transparency (no way to store an isolated light source with a transparent background)
- The shared exponent architecture can occasionally introduce banding or color artifacts in extreme edge cases compared to true 16-bit/32-bit floating-point formats like OpenEXR
- Zero native browser support for 2D viewing
When to choose which format
MrSID
Use MrSID when…
- Geographic Information Systems (GIS)
- Satellite Imagery Archival
- Aerial Orthophotography Mosaics
Radiance
Use Radiance when…
- Image-Based Lighting (IBL)
- 3D Environment Maps (HDRI Skydomes)
- Lighting Simulation
- VFX and CGI Rendering