Free webp to jpg
EN
Image MIME Reference
Harlequin-PGB

Global Graphics Page Graphics Buffer

image/vnd.globalgraphics.pgb
VS

JPEG XL

image/jxl
JXL

A complete technical comparison of Global Graphics Page Graphics Buffer and JPEG XL — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

JXL wins on browser support

Feature Support

Feature Harlequin-PGB JXL
Transparency (Alpha) ✕ No Yes
Animation Support ✕ No Yes
Progressive Loading ✕ No Yes
HDR Support ✕ No Yes
EXIF Metadata ✕ No Yes
ICC Color Profile Yes Yes
Global Graphics Page Graphics Buffer
image/vnd.globalgraphics.pgb
Extension
.pgb
Container Proprietary Harlequin Raster Container
Compression Uncompressed / Run-Length Encoding (RLE)
Algorithm
Proprietary RLENone
Color Depth 1-bit (Monochrome Separations), 8-bit (Grayscale), 8-bit/10-bit (Contone), CMYK / N-Color Spot Channels
Developed by Global Graphics Software (Hybrid Software Group)
Released 1990s
Magic Bytes
Unknown (Proprietary Harlequin Header)
Full Harlequin-PGB reference →
JPEG XL
image/jxl
Extension
.jxl
Container ISOBMFF / JPEG XL Codestream
Compression Lossy (VarDCT) / Lossless (Modular)
Algorithm
VarDCT (Variable block-size DCT)Modular (Predictive coding for lossless)
Color Depth 8-bit, 10-bit, 12-bit, 16-bit, 32-bit (Float)
Developed by Joint Photographic Experts Group (JPEG)
Released 2021
Magic Bytes
FF 0A (Codestream) / 00 00 00 0C 4A 58 4C 20 0D 0A 87 0A (Container)
Full JXL reference →

Browser Support Comparison

Browser Harlequin-PGB JXL
Chrome Chrome
✕ ✕
Firefox Firefox
✕ ✕
Safari Safari
✕
✓ 17+
Edge Edge
✕ ✕
IE IE (Legacy)
✕ ✕
Harlequin-PGB

Harlequin-PGB Strengths

  • Unlike generic 1-bit TIFFs, PGB files inherently encapsulate vital print-job metadata within their headers (e.g., job name, page number, separation colors, screening angles)
  • Highly optimized for ultra-fast viewing and processing within professional printing workflows
Limitations
  • Completely proprietary and closed-source, locking its usage strictly to Harlequin-powered RIP environments
  • Zero support in standard desktop operating systems, web browsers, or consumer image editing software like Photoshop or GIMP
JXL

JXL Strengths

  • Capable of losslessly recompressing legacy JPEG files, saving ~20% space while retaining perfect byte-for-byte restorability
  • Highly superior progressive decoding (Saliency-driven), allowing recognizable images to load extremely fast on slow connections
  • Outperforms WebP and competes favorably with AVIF, especially at high-fidelity settings and for complex textures/photography
  • Royalty-free with an open-source reference implementation (libjxl)
Limitations
  • Google's removal of JXL support from Chrome severely hindered its adoption as a universal web standard
  • Lack of hardware decoding chips compared to video-derived codecs like AVIF (AV1)
  • File parsing logic is complex due to the split between raw codestreams and ISOBMFF containers

When to choose which format

Harlequin-PGB
Use Harlequin-PGB when…
  • Commercial Printing Output
  • Computer-to-Plate (CTP) Manufacturing
  • Prepress Soft Proofing (e.g., FirstPROOF)
  • Harlequin RIP Spooling Pipelines
JXL
Use JXL when…
  • High-End Web Delivery (via Safari/Polyfills)
  • HDR Photography
  • Legacy JPEG Archiving
  • Digital Art & Image Storage

More comparisons

Harlequin-PGB vs ACES → JXL vs ACES → Harlequin-PGB vs APNG → JXL vs APNG → Harlequin-PGB vs AVCI → JXL vs AVCI → Harlequin-PGB vs AVCS → JXL vs AVCS → Harlequin-PGB vs AVIF → JXL vs AVIF → All comparisons →
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