Free webp to jpg
Image MIME Reference
JPEG-XR-(HEIF)

JPEG XR Image (HEIF Container)

image/jxra
VS

PWG Raster Format

image/pwg-raster
PWG-Raster

A complete technical comparison of JPEG XR Image (HEIF Container) and PWG Raster Format — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

Equal browser support

Feature Support

Feature JPEG-XR-(HEIF) PWG-Raster
Transparency (Alpha) Yes ✕ No
Animation Support ✕ No ✕ No
Progressive Loading Yes ✕ No
HDR Support Yes ✕ No
EXIF Metadata Yes ✕ No
ICC Color Profile Yes ✕ No
JPEG XR Image (HEIF Container)
image/jxra
Extension
.jxra
Container HEIF / ISOBMFF (ISO/IEC 23008-12 / Annex F of ITU-T T.832)
Compression Lossy / Lossless
Algorithm
JPEG XR (Lapped Biorthogonal Transform)
Color Depth 8-bit, 16-bit, 32-bit (Float)
Developed by ISO/IEC JTC 1 / ITU-T
Released 2019
Magic Bytes
XX XX XX XX 66 74 79 70 6A 78 72 41
Full JPEG-XR-(HEIF) reference →
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
Full PWG-Raster reference →

Browser Support Comparison

Browser JPEG-XR-(HEIF) PWG-Raster
Chrome Chrome
Firefox Firefox
Safari Safari
Edge Edge
IE IE (Legacy)
JPEG-XR-(HEIF)

JPEG-XR-(HEIF) Strengths

  • Combines the deep color (32-bit float) and mathematically lossless compression of JPEG XR with the robust metadata architecture of HEIF
  • Allows grouping multiple images, exposure brackets, or focal stacks into a single file collection
Limitations
  • Practically non-existent software and operating system support compared to standard HEIC or legacy JPEG XR (.jxr)
  • Zero web browser support, rendering it entirely unsuitable for public web deployment
  • Eclipsed by modern standards like AVIF and JPEG XL which offer superior compression with much broader industry backing
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

JPEG-XR-(HEIF)
Use JPEG-XR-(HEIF) when…
  • Specialized Archival
  • Experimental Imaging Workflows
  • High Dynamic Range (HDR) Imaging
PWG-Raster
Use PWG-Raster when…
  • Driverless Network Printing (IPP Everywhere)
  • Apple AirPrint and Mopria Print Service Pipelines
  • CUPS (Common UNIX Printing System) Spooling
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