Free webp to jpg
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Image MIME Reference
JPX

JPEG 2000 Part 2 (Extended)

image/jpx
VS

GIMP Image Format

image/x-xcf
XCF

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

Equal browser support

Feature Support

Feature JPX XCF
Transparency (Alpha) Yes Yes
Animation Support Yes Yes
Progressive Loading Yes ✕ No
HDR Support Yes Yes
EXIF Metadata Yes Yes
ICC Color Profile Yes Yes
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 →
GIMP Image Format
image/x-xcf
Extension
.xcf
Container GIMP Hierarchical Chunk Container
Compression None / RLE (Run-Length Encoding) / Zlib / Deflate (In newer GIMP versions)
Algorithm
NoneRLEZlib
Color Depth 8-bit per channel, 16-bit per channel, 32-bit floating point
Developed by Spencer Kimball, Peter Mattis, and the GIMP Development Team
Released 1995
Magic Bytes
67 69 6D 70 20 78 63 66
Full XCF reference →

Browser Support Comparison

Browser JPX XCF
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
XCF

XCF Strengths

  • Preserves all non-destructive editing elements, layer hierarchies, masks, and alpha channels across GIMP sessions
  • Open and thoroughly documented specification within the open-source community, allowing third-party tools like Krita and ImageMagick to read project files
  • Reliable magic byte header prevents misidentification
Limitations
  • Massive file sizes because raw, unflattened layer bitmaps and masks are stored directly within the project archive
  • Completely proprietary to the GIMP ecosystem for deep editing; cannot be natively rendered or parsed by web browsers
  • Third-party software supporting XCF may occasionally struggle to render complex text layer adjustments or advanced layer blend modes identically to GIMP

When to choose which format

JPX
Use JPX when…
  • Prepress & Commercial Printing (CMYK)
  • Geospatial Data
  • Archival Preservation
  • Medical Imaging
XCF
Use XCF when…
  • GIMP Native Project Archival
  • Layered Photo Editing and Graphic Design
  • Intermediary Asset Preparation for Export

More comparisons

JPX vs ACES → XCF vs ACES → JPX vs APNG → XCF vs APNG → JPX vs AVCI → XCF vs AVCI → JPX vs AVCS → XCF vs AVCS → JPX vs AVIF → XCF vs AVIF → All comparisons →
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