Free webp to jpg
Image MIME Reference
BMP

Windows Bitmap (Legacy Windows MIME Alias)

image/x-windows-bmp
VS

Global Graphics Page Graphics Buffer

image/vnd.globalgraphics.pgb
Harlequin-PGB

A complete technical comparison of Windows Bitmap (Legacy Windows MIME Alias) and Global Graphics Page Graphics Buffer — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

BMP wins on browser support

Feature Support

Feature BMP Harlequin-PGB
Transparency (Alpha) Yes ✕ No
Animation Support ✕ No ✕ No
Progressive Loading ✕ No ✕ No
HDR Support ✕ No ✕ No
EXIF Metadata ✕ No ✕ No
ICC Color Profile Yes Yes
Windows Bitmap (Legacy Windows MIME Alias)
image/x-windows-bmp
Extension
.bmp.dib
Container DIB (Device-Independent Bitmap)
Compression Uncompressed / Run-Length Encoding (RLE)
Algorithm
NoneRLE4RLE8
Color Depth 1-bit (Monochrome), 4-bit (16 colors), 8-bit (256 colors), 16-bit (High Color), 24-bit (True Color), 32-bit (True Color with Alpha)
Developed by Microsoft Corporation
Released 1985
Magic Bytes
42 4D
Full BMP reference →
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 →

Browser Support Comparison

Browser BMP Harlequin-PGB
Chrome Chrome
✓ 1
Firefox Firefox
✓ 1
Safari Safari
✓ 1
Edge Edge
✓ 12
IE IE (Legacy)
BMP

BMP Strengths

  • Universally supported by all major operating systems and modern web browsers
  • Maintains perfect, lossless fidelity because pixel data is stored without lossy compression artifacts
Limitations
  • Massive file size overhead due to a lack of modern compression algorithms
  • Legacy MIME strings like 'image/x-windows-bmp' can trigger validation warnings in strict security or API environments if unhandled
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

When to choose which format

BMP
Use BMP when…
  • Legacy Windows Desktop Registry Associations
  • Older Enterprise Intranet Applications
  • Windows Graphics Archival
Harlequin-PGB
Use Harlequin-PGB when…
  • Commercial Printing Output
  • Computer-to-Plate (CTP) Manufacturing
  • Prepress Soft Proofing (e.g., FirstPROOF)
  • Harlequin RIP Spooling Pipelines
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