Image MIME Reference
DDS
DirectDraw Surface
image/vnd.ms-dds
VS
Network FlashPix
image/vnd.net-fpx
Net-FPX
A complete technical comparison of DirectDraw Surface and Network FlashPix — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | DDS | Net-FPX |
|---|---|---|
| Transparency (Alpha) | Yes | Yes |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | Yes |
| HDR Support | Yes | ✕ No |
| EXIF Metadata | ✕ No | Yes |
| ICC Color Profile | ✕ No | Yes |
DirectDraw Surface
image/vnd.ms-dds
Extension
.dds
Container
DirectDraw Surface
Compression
Block Compression (BC1-BC7) / DXTC / S3TC / Uncompressed (RGBA, Floating-Point)
Algorithm
DXT1-DXT5BC1-BC7ASTC / ETC2 (Extended)
Color Depth
8-bit, 16-bit, 24-bit, 32-bit (RGBA), 16-bit/32-bit Floating Point (HDR)
Developed by
Microsoft Corporation
Released
1999
Magic Bytes
44 44 53 20
Network FlashPix
image/vnd.net-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
Digital Imaging Group (Kodak, HP, Live Picture, Microsoft)
Released
1996
Magic Bytes
D0 CF 11 E0 A1 B1 1A E1
Browser Support Comparison
| Browser | DDS | Net-FPX |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
DDS
DDS Strengths
- Massively reduces VRAM footprint and memory bandwidth usage because the GPU decodes the block compression in hardware
- Encapsulates complex texture arrays, volume textures, cubemaps, and entire mipmap chains within a single, highly structured file
- Supports high-dynamic-range (HDR) floating-point data for modern physically based rendering (PBR)
Limitations
- Block compression algorithms (like DXT) are lossy and can introduce ugly blocky artifacts, especially in smooth gradients or normal maps if not tuned properly
- Files are generally larger on the physical hard drive than highly compressed formats like PNG or WebP
- Zero support in web browsers or standard consumer image viewers
Net-FPX
Net-FPX Strengths
- Revolutionized web imaging in the late 1990s by proving that massive gigapixel images could be navigated seamlessly over 56k dial-up modems
- Pioneered the tile-based, multi-resolution pyramid concepts that eventually evolved into modern standards like IIIF (International Image Interoperability Framework)
Limitations
- Completely obsolete, having been replaced by standard JPEG servers and modern tiling formats like Deep Zoom or JPEG 2000/XR
- Relied on proprietary Java applets or ActiveX controls to render the tiles dynamically in a web browser
- Extremely complex to parse server-side due to the heavy OLE filesystem container
When to choose which format
DDS
Use DDS when…
- Real-Time 3D Game Textures
- DirectX and Vulkan Rendering Pipelines
- Skyboxes and Environment Cubemaps
- Volume Textures (3D Textures)
Net-FPX
Use Net-FPX when…
- Historical Internet Imaging Protocol (IIP) Streaming
- Early E-Commerce Deep Zoom Implementations
- Legacy High-Resolution Image Servers