Free webp to jpg
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Image MIME Reference
JPX

JPEG 2000 Part 2 (Extended)

image/jpx
VS

Nikon Electronic Format

image/x-nikon-nef
Nikon-NEF

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

Equal browser support

Feature Support

Feature JPX Nikon-NEF
Transparency (Alpha) Yes ✕ No
Animation Support Yes ✕ No
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 →
Nikon Electronic Format
image/x-nikon-nef
Extension
.nef
Container TIFF
Compression Uncompressed / Lossless Compressed / Lossy Compressed (High Efficiency)
Algorithm
NoneNikon Proprietary LosslessNikon High Efficiency Lossy
Color Depth 12-bit (Per Channel), 14-bit (Per Channel)
Developed by Nikon Corporation
Released 1999
Magic Bytes
49 49 2A 00 or 4D 4D 00 2A
Full Nikon-NEF reference →

Browser Support Comparison

Browser JPX Nikon-NEF
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
Nikon-NEF

Nikon-NEF Strengths

  • Retains maximum sensor data, allowing extreme recovery of highlights and shadows that would be permanently lost in a JPEG
  • White balance, sharpening, and color profiling are saved as metadata instructions rather than 'baked in', meaning they can be completely altered in post-production without degrading the image
  • Embeds a high-quality JPEG preview inside the raw file for rapid culling and viewing
Limitations
  • Proprietary format means it requires constant updates to raw processing engines every time Nikon releases a new camera model
  • Produces very large file sizes (often 20MB to 50MB+ per image depending on sensor resolution and bit-depth)
  • Cannot be directly embedded into web pages or used in standard HTML/CSS contexts

When to choose which format

JPX
Use JPX when…
  • Prepress & Commercial Printing (CMYK)
  • Geospatial Data
  • Archival Preservation
  • Medical Imaging
Nikon-NEF
Use Nikon-NEF when…
  • Professional Digital Photography
  • Non-destructive Image Post-Processing
  • High Dynamic Range (HDR) Imaging Archival

More comparisons

JPX vs ACES → Nikon-NEF vs ACES → JPX vs APNG → Nikon-NEF vs APNG → JPX vs AVCI → Nikon-NEF vs AVCI → JPX vs AVCS → Nikon-NEF vs AVCS → JPX vs AVIF → Nikon-NEF vs AVIF → All comparisons →
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