Image MIME Reference
MrSID
Multi-resolution Seamless Image Database
image/x-mrsid-image
VS
Tagged Image File Format (Legacy MIME)
image/x-tiff
TIFF
A complete technical comparison of Multi-resolution Seamless Image Database and Tagged Image File Format (Legacy MIME) — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | MrSID | TIFF |
|---|---|---|
| Transparency (Alpha) | Yes | Yes |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | Yes | ✕ No |
| HDR Support | ✕ No | Yes |
| EXIF Metadata | Yes | Yes |
| ICC Color Profile | Yes | Yes |
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
Tagged Image File Format (Legacy MIME)
image/x-tiff
Extension
.tiff.tif
Container
IFD (Image File Directory) Tag Structure
Compression
Uncompressed / LZW (Lossless) / ZIP / Deflate (Lossless) / PackBits (Lossless RLE) / JPEG (Lossy) / CCITT Group 3/4 (Fax/Document)
Algorithm
NoneLZWDeflatePackBitsJPEGCCITT
Color Depth
1-bit (Monochrome), 8-bit (Grayscale or Indexed), 16-bit (Per Channel), 32-bit (Float Per Channel)
Developed by
Aldus Corporation (Later acquired by Adobe Systems)
Released
1986
Magic Bytes
49 49 2A 00 (Little-endian) or 4D 4D 00 2A (Big-endian)
Browser Support Comparison
| Browser | MrSID | TIFF |
|---|---|---|
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
TIFF
TIFF Strengths
- Universally accepted as the gold standard for high-fidelity archival and professional print workflows
- Highly adaptable structure supports multiple pages (documents), layers, vast bit depths, and diverse compression algorithms within a single file
- Unmatched support for rich metadata including EXIF, IPTC, XMP, and custom ICC color profiles
Limitations
- Produces exceptionally large file sizes compared to modern web formats
- The 'x-tiff' legacy MIME string forces developers to write extra validation logic to prevent strict security filters from rejecting valid uploads
- The format's immense complexity means that many lightweight parsers only implement a subset of the specification, sometimes failing to read obscure compressions (like CCITT or old JPEG-in-TIFF)
When to choose which format
MrSID
Use MrSID when…
- Geographic Information Systems (GIS)
- Satellite Imagery Archival
- Aerial Orthophotography Mosaics
TIFF
Use TIFF when…
- Professional Print and Desktop Publishing
- High-Resolution Archival Scanning
- Master Copies of Digital Photography