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Image MIME Reference
JPEG-XR

JPEG XR (HD Photo)

image/vnd.ms-photo
VS

Khronos Texture

image/ktx
KTX

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

Equal browser support

Feature Support

Feature JPEG-XR KTX
Transparency (Alpha) Yes Yes
Animation Support ✕ No ✕ No
Progressive Loading Yes ✕ No
HDR Support Yes Yes
EXIF Metadata Yes ✕ No
ICC Color Profile Yes ✕ No
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 →
Khronos Texture
image/ktx
Extension
.ktx
Container KTX (Khronos Texture 1.1)
Compression Uncompressed / GPU Compressed (ASTC, ETC, BCn, PVRTC)
Algorithm
ASTCETC1 / ETC2BCn (DXT)PVRTCBasis Universal (in KTX2)
Color Depth 8-bit, 16-bit, 32-bit (Integer/Float)
Developed by Khronos Group
Released 2010
Magic Bytes
AB 4B 54 58 20 31 31 BB 0D 0A 1A 0A
Full KTX reference →

Browser Support Comparison

Browser JPEG-XR KTX
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
KTX

KTX Strengths

  • Enables direct-to-GPU texture uploading, drastically reducing load times and CPU overhead in 3D applications
  • Supports complex texture types natively (mipmaps, cubemaps, 3D volumes, texture arrays)
  • Standardized across major Khronos APIs (OpenGL, Vulkan, WebGL) unlike vendor-specific formats like DDS
Limitations
  • Requires custom JavaScript loaders to parse and display on the web
  • Zero native support in consumer image viewers or 2D photo editing software
  • Format fragmentation: a KTX file containing an ASTC payload will fail to render on hardware that only supports BCn compression (KTX2 and Basis Universal solve this)

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
KTX
Use KTX when…
  • Real-time 3D Graphics
  • WebGL / WebGPU Applications
  • Mobile Games
  • Virtual/Augmented Reality (VR/AR)
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