Free webp to jpg
Image MIME Reference
Net-FPX

Network FlashPix

image/vnd.net-fpx
VS

Radiance HDR

image/vnd.radiance
Radiance

A complete technical comparison of Network FlashPix and Radiance HDR — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

Equal browser support

Feature Support

Feature Net-FPX Radiance
Transparency (Alpha) Yes ✕ No
Animation Support ✕ No ✕ No
Progressive Loading Yes ✕ No
HDR Support ✕ No Yes
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
Full Net-FPX reference →
Radiance HDR
image/vnd.radiance
Extension
.hdr.pic.rgbe.xyze
Container Radiance Information Header
Compression Run-Length Encoding (RLE) / Uncompressed
Algorithm
Adaptive Run-Length Encoding (RLE)
Color Depth 32-bit (8-bit per channel RGB + 8-bit shared Exponent)
Developed by Greg Ward (Lawrence Berkeley National Laboratory)
Released 1989
Magic Bytes
23 3F 52 41 44 49 41 4E 43 45
Full Radiance reference →

Browser Support Comparison

Browser Net-FPX Radiance
Chrome Chrome
Firefox Firefox
Safari Safari
Edge Edge
IE 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  • Completely obsolete, having been replaced by standard JPEG servers and modern tiling formats like Deep Zoom or JPEG 2000/XR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
Radiance

Radiance Strengths

  • Universally supported by almost every 3D modeling software, renderer, and game engine in existence
  • RGBE encoding offers a brilliant balance between High Dynamic Range capability and small file size (compared to 32-bit float OpenEXR)
  • Simple, easy-to-parse ASCII header followed by straightforward RLE binary data
Limitations
  • Does not support alpha transparency (no way to store an isolated light source with a transparent background)
  • The shared exponent architecture can occasionally introduce banding or color artifacts in extreme edge cases compared to true 16-bit/32-bit floating-point formats like OpenEXR
  • Zero native browser support for 2D viewing

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
Radiance
Use Radiance when…
  • Image-Based Lighting (IBL)
  • 3D Environment Maps (HDRI Skydomes)
  • Lighting Simulation
  • VFX and CGI Rendering
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