Free webp to jpg
Image MIME Reference
JPEG-XR

JPEG XR (HD Photo)

image/vnd.ms-photo
VS

Network FlashPix

image/vnd.net-fpx
Net-FPX

A complete technical comparison of JPEG XR (HD Photo) and Network FlashPix — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

Equal browser support

Feature Support

Feature JPEG-XR Net-FPX
Transparency (Alpha) Yes Yes
Animation Support ✕ No ✕ No
Progressive Loading Yes Yes
HDR Support Yes ✕ No
EXIF Metadata Yes Yes
ICC Color Profile Yes Yes
JPEG XR (HD Photo)
image/vnd.ms-photo
Extension
.jxr.wdp.hdp
Container TIFF-like Image File Directory (IFD)
Compression Lossy (Lapped Bi-orthogonal Transform) / Lossless
Algorithm
Lapped Bi-orthogonal Transform (LBT)
Color Depth 8-bit (Grayscale, RGB, CMYK), 16-bit, 32-bit Floating Point (HDR)
Developed by Microsoft Corporation (later Joint Photographic Experts Group)
Released 2006
Magic Bytes
49 49 BC 01
Full JPEG-XR reference →
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 →

Browser Support Comparison

Browser JPEG-XR Net-FPX
Chrome Chrome
Firefox Firefox
Safari Safari
Edge Edge
IE IE (Legacy)
JPEG-XR

JPEG-XR Strengths

  • Excellent support for 16-bit and 32-bit floating-point HDR images without massive file size bloat
  • Native support for alpha transparency, which standard JPEG fundamentally lacks
  • Computational complexity for decoding/encoding is relatively low, making it hardware-friendly
Limitations
  • Suffered a complete failure of adoption in the web browser market outside of Microsoft's ecosystem
  • Fully superseded by modern, open formats like WebP, AVIF, and JPEG XL which offer better compression and universal browser support
  • Multiple file extensions (.wdp, .hdp, .jxr) and MIME types cause confusion and parsing fragmentation
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

JPEG-XR
Use JPEG-XR when…
  • Legacy Windows Desktop Backgrounds
  • XPS (XML Paper Specification) Documents
  • Early High Dynamic Range (HDR) Photography
  • DirectX Textures
Net-FPX
Use Net-FPX when…
  • Historical Internet Imaging Protocol (IIP) Streaming
  • Early E-Commerce Deep Zoom Implementations
  • Legacy High-Resolution Image Servers
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