Free webp to jpg
Image MIME Reference
JPX

JPEG 2000 Part 2 (Extended)

image/jpx
VS

QuickTime Image Format

image/x-quicktime
QTIF

A complete technical comparison of JPEG 2000 Part 2 (Extended) and QuickTime Image Format — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

Equal browser support

Feature Support

Feature JPX QTIF
Transparency (Alpha) Yes Yes
Animation Support Yes ✕ No
Progressive Loading Yes ✕ No
HDR Support Yes ✕ No
EXIF Metadata Yes ✕ No
ICC Color Profile Yes ✕ No
JPEG 2000 Part 2 (Extended)
image/jpx
Extension
.jpx.jpf
Container ISOBMFF / JPX (ISO/IEC 15444-2)
Compression Lossy / Lossless
Algorithm
Discrete Wavelet Transform (DWT)
Color Depth 8-bit, 16-bit, 32-bit, 38-bit
Developed by Joint Photographic Experts Group (JPEG)
Released 2002
Magic Bytes
00 00 00 0C 6A 50 20 20 0D 0A 87 0A ... 66 74 79 70 6A 70 78 20
Full JPX reference →
QuickTime Image Format
image/x-quicktime
Extension
.qtif.qti.qif
Container QuickTime Atom Container
Compression Varies (JPEG, SMC, Apple Video, Cinepak, Uncompressed)
Algorithm
QuickTime Image Compression Manager (ICM) Codecs
Color Depth 1-bit to 32-bit (Varies depending on the enclosed codec)
Developed by Apple Computer, Inc.
Released 1991
Magic Bytes
Varies (Typically begins with a 32-bit size integer followed by 69 64 73 63 ('idsc'))
Full QTIF reference →

Browser Support Comparison

Browser JPX QTIF
Chrome Chrome
Firefox Firefox
Safari Safari
Edge Edge
IE IE (Legacy)
JPX

JPX Strengths

  • Removes the color space limitations of baseline JP2, adding native support for CMYK, CIE Lab, and custom vendor color spaces
  • Supports multiple codestreams in a single file, allowing for rich compositing and animation
  • Enables fragmented files where image data and metadata can reside in separate physical files via data references
Limitations
  • Extremely complex specification makes full software implementation rare, leading to compatibility issues
  • Zero web browser support, rendering it unsuitable for public internet distribution
  • Often overkill for standard imaging tasks where baseline JP2 or modern alternatives like AVIF suffice
QTIF

QTIF Strengths

  • Extremely flexible architecture allowing it to encapsulate virtually any image compression algorithm available on the host machine
  • Supported 32-bit images with alpha channels (transparency) long before PNG became an established standard
Limitations
  • Fundamentally tied to Apple's deprecated QuickTime architecture, rendering the files almost entirely unreadable on modern systems without specialized legacy software or FFmpeg
  • The 'wrapper' nature of the format means that even if a parser can read the QTIF container, it may fail to render the image if it lacks the specific proprietary codec (like Apple SMC) used to compress the pixel data
  • Zero native support in modern web browsers

When to choose which format

JPX
Use JPX when…
  • Prepress & Commercial Printing (CMYK)
  • Geospatial Data
  • Archival Preservation
  • Medical Imaging
QTIF
Use QTIF when…
  • Classic Mac OS Applications and Backgrounds
  • QuickTime VR Panorama Textures
  • 1990s CD-ROM Multimedia Assets
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