Free webp to jpg
Image MIME Reference
BMP

Windows Bitmap (Legacy Windows MIME Alias)

image/x-windows-bmp
VS

High-Throughput JPEG 2000 Image

image/jph
HTJ2K-(JPH)

A complete technical comparison of Windows Bitmap (Legacy Windows MIME Alias) and High-Throughput JPEG 2000 Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

BMP wins on browser support

Feature Support

Feature BMP HTJ2K-(JPH)
Transparency (Alpha) Yes Yes
Animation Support ✕ No ✕ No
Progressive Loading ✕ No Yes
HDR Support ✕ No Yes
EXIF Metadata ✕ No Yes
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 →
High-Throughput JPEG 2000 Image
image/jph
Extension
.jph
Container JPH (ISO/IEC 15444-15)
Compression Lossy / Lossless
Algorithm
High-Throughput JPEG 2000 (HTJ2K)
Color Depth 8-bit, 16-bit, 32-bit, 38-bit
Developed by Joint Photographic Experts Group (JPEG)
Released 2019
Magic Bytes
00 00 00 0C 6A 50 20 20 0D 0A 87 0A ... 66 74 79 70 6A 70 68 20
Full HTJ2K-(JPH) reference →

Browser Support Comparison

Browser BMP HTJ2K-(JPH)
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
HTJ2K-(JPH)

HTJ2K-(JPH) Strengths

  • Delivers orders of magnitude faster encoding and decoding than standard JPEG 2000 by utilizing a new, parallelizable block coder
  • Supports mathematically lossless and lossy compression within the same codestream architecture
  • Allows for resolution scalability, progressive decoding, and region-of-interest extraction without needing to decode the entire image
Limitations
  • Zero native web browser support, requiring specialized libraries, API conversions, or WebAssembly (like OpenJPH.js) for web deployment
  • Lack of broad consumer awareness, keeping it confined to professional, medical, and scientific workflows
  • Requires more advanced software ecosystems to decode than ubiquitous formats like JPEG or WebP

When to choose which format

BMP
Use BMP when…
  • Legacy Windows Desktop Registry Associations
  • Older Enterprise Intranet Applications
  • Windows Graphics Archival
HTJ2K-(JPH)
Use HTJ2K-(JPH) when…
  • Medical Imaging (DICOM)
  • Geospatial Data
  • Digital Cinema
  • Professional Archiving
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