Image MIME Reference
FPX
FlashPix
image/vnd.fpx
VS
Microsoft Document Imaging
image/vnd.ms-modi
MODI
A complete technical comparison of FlashPix and Microsoft Document Imaging — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | FPX | MODI |
|---|---|---|
| Transparency (Alpha) | Yes | ✕ No |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | ✕ No | ✕ No |
| EXIF Metadata | Yes | ✕ No |
| ICC Color Profile | Yes | ✕ No |
FlashPix
image/vnd.fpx
Extension
.fpx
Container
Microsoft OLE Structured Storage (COM)
Compression
JPEG (Lossy) / Uncompressed / Single-color (Solid)
Algorithm
JPEGNone
Color Depth
8-bit (Grayscale/Indexed), 24-bit (RGB), 32-bit (CMYK/RGBA)
Developed by
Eastman Kodak, Microsoft, Hewlett-Packard, Live Picture
Released
1996
Magic Bytes
D0 CF 11 E0 A1 B1 1A E1
Microsoft Document Imaging
image/vnd.ms-modi
Extension
.mdi
Container
TIFF Variant
Compression
LZW / Proprietary MS Compression
Algorithm
LZW (Modified)
Color Depth
1-bit (Monochrome), 8-bit (Grayscale), 24-bit (RGB)
Developed by
Microsoft Corporation
Released
2001
Magic Bytes
49 49 2A 00
Browser Support Comparison
| Browser | FPX | MODI |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
FPX
FPX Strengths
- Allowed early, low-RAM computers to view and edit massive, high-resolution digital photos instantly by only loading the needed tiles and resolutions
- Pioneered the multi-resolution pyramid and tiling concepts heavily used today in modern deep-zoom and web mapping applications (like Google Maps)
Limitations
- Completely obsolete and unsupported by modern web browsers or operating systems
- Uses the complex, proprietary Microsoft OLE container format, making it incredibly difficult to parse or extract data from without dedicated legacy libraries
- Prone to being misidentified by MIME sniffers as an old Microsoft Office document
MODI
MODI Strengths
- Historically provided an excellent all-in-one scanned document format with built-in OCR and annotations before PDF editing became universally accessible
- Tightly integrated with Microsoft Office and SharePoint workflows in the early 2000s
Limitations
- Completely proprietary and obsolete; Microsoft abandoned it in favor of standard TIFF and PDF
- Causes widespread identification conflicts since its file signature is identical to a standard TIFF
- Extremely difficult to open on modern operating systems without relying on third-party conversion utilities
When to choose which format
FPX
Use FPX when…
- Legacy Digital Photography
- Kodak Picture CDs (Historical)
- Early High-Resolution Image Viewers
MODI
Use MODI when…
- Legacy Scanned Document Archival
- Microsoft Office XP/2003/2007 Workflows
- Embedded OCR Text Storage