Image MIME Reference
Net-FPX
Network FlashPix
image/vnd.net-fpx
VS
PiCture eXchange
image/x-pcx
PCX
A complete technical comparison of Network FlashPix and PiCture eXchange — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | Net-FPX | PCX |
|---|---|---|
| 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
PiCture eXchange
image/x-pcx
Extension
.pcx
Container
ZSoft Proprietary Header (128 bytes)
Compression
Run-Length Encoding (RLE)
Algorithm
ZSoft RLE
Color Depth
1-bit (Monochrome), 4-bit (16 colors), 8-bit (256 colors), 24-bit (True Color)
Developed by
ZSoft Corporation
Released
1985
Magic Bytes
0A (followed by version, e.g., 0A 05 01 08)
Browser Support Comparison
| Browser | Net-FPX | PCX |
|---|---|---|
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- Completely obsolete, having been replaced by standard JPEG servers and modern tiling formats like Deep Zoom or JPEG 2000/XR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
PCX
PCX Strengths
- Incredibly simple RLE algorithm makes it very fast to decode, which was historically vital for early 3D video game engines
- Retains crisp, lossless pixel data suitable for pixel art and interface assets
- Well-documented and highly supported by older desktop publishing and image editing software
Limitations
- Extremely inefficient compression by modern standards, producing large file sizes compared to PNG
- Lacks modern imaging features such as alpha channel transparency, EXIF metadata, and color profiles
- Zero support in web browsers; must be converted to PNG for web use
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
PCX
Use PCX when…
- MS-DOS and Early Windows Graphics
- 1990s Video Game Assets (Textures, UI)
- Retro Computing Archival