Image MIME Reference
Net-FPX
Network FlashPix
image/vnd.net-fpx
VS
PWG Raster Format
image/pwg-raster
PWG-Raster
A complete technical comparison of Network FlashPix and PWG Raster Format — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | Net-FPX | PWG-Raster |
|---|---|---|
| Transparency (Alpha) | Yes | ✕ No |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | Yes | ✕ No |
| HDR Support | ✕ No | ✕ No |
| EXIF Metadata | Yes | ✕ No |
| ICC Color Profile | Yes | ✕ No |
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
PWG Raster Format
image/pwg-raster
Extension
.pwg.ras
Container
CUPS Raster v2 Container
Compression
PackBits (Run-Length Encoding)
Algorithm
PackBits (Apple RLE variant)
Color Depth
1-bit (Monochrome/K), 8-bit (Grayscale), 24-bit (sRGB / Adobe RGB), 32-bit (CMYK)
Developed by
IEEE-ISTO Printer Working Group (PWG)
Released
2011
Magic Bytes
52 61 53 32
Browser Support Comparison
| Browser | Net-FPX | PWG-Raster |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
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- Completely obsolete, having been replaced by standard JPEG servers and modern tiling formats like Deep Zoom or JPEG 2000/XR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
PWG-Raster
PWG-Raster Strengths
- The undisputed global standard for modern, driverless printing environments, eliminating the nightmare of installing manufacturer-specific print drivers
- Extremely lightweight to decode on embedded hardware, requiring minimal RAM buffers on the printer side
- Strict color space and resolution rules guarantee that the printed output will successfully process without syntax errors
Limitations
- Generates massive file sizes and network payloads compared to vector-based formats like PDF or PostScript, as every page is fully rasterized at 300+ DPI before transmission
- No support for native rendering in web browsers, image viewers, or graphic design software without specialized CUPS developer tools
- Cannot store complex metadata, vector text, or layers
When to choose which format
Net-FPX
Use Net-FPX when…
- Historical Internet Imaging Protocol (IIP) Streaming
- Early E-Commerce Deep Zoom Implementations
- Legacy High-Resolution Image Servers
PWG-Raster
Use PWG-Raster when…
- Driverless Network Printing (IPP Everywhere)
- Apple AirPrint and Mopria Print Service Pipelines
- CUPS (Common UNIX Printing System) Spooling