cNEFX

Merge Nikon pixel-shift captures into NEFX files on Linux, macOS and Windows. cNEFX accepts complete 4, 8, 16 or 32-frame sequences from the Z8, Zf, Z6III and Z5II. It runs natively, with no Nikon software or Python runtime required.

Experimental: validation against authentic captures, NX Studio references and Lightroom Classic is partial.

Install

Install with mise (recommended):

mise use -g github:ChrAlpha/cNEFX@latest
cnefx merge --help

Or run without adding cNEFX to your global configuration:

mise x github:ChrAlpha/cNEFX@latest -- cnefx merge --help

For Node.js users, run with pnx:

pnx cnefx-cli merge --help

Or install globally with pnpm:

pnpm add -g cnefx-cli

Update with mise upgrade github:ChrAlpha/cNEFX or pnpm update -g cnefx-cli. You can also build from source or download native archives from Releases. Builds cover Linux x86_64/ARM64, macOS Apple silicon and Windows x86_64. Check the accompanying .sha256 file, extract the archive, and add its bin directory to PATH. Builds are unsigned and not notarized; older-system compatibility is not established.

Merge pixel-shift captures

Use lossless-compressed, 14-bit FX NEF files. Pass a card folder, files or a file-name pattern; no other option is needed:

cnefx merge /path/to/DCIM/100NZ_8

cNEFX finds the pixel-shift sequences, as NX Studio does, and writes each one beside its first capture, e.g. SGL_6243_merged.NEFX. Other photos are skipped. With AE bracketing every exposure is its own sequence and output. Running the same command again only merges what is missing, so an interrupted or partly failed run can simply be repeated; existing files are never replaced.

Use --output FILE.nefx for a single sequence or --output-directory DIR to publish all outputs with a manifest.json together. HE/HE* is unsupported; HLG, other image areas and untested firmware/settings remain unvalidated.

Output modes

--outputs N sets the outputs per sequence and defaults to 1. Several outputs are named NAME_merged_01.NEFX onward; --output accepts only one.

| Captures | Allowed outputs | Dimensions per output, relative to the source crop | | --- | --- | --- | | 4 | 1 | Original width and height | | 8 | 1, 2 | Original width and height | | 16 | 1, 4 | 2x width and height for one output; original for four | | 32 | 1, 2, 4, 8 | 2x width and height for one or two outputs; original for four or eight |

Options

• --jobs N: set the worker limit (1-256; default: all cores). Use --jobs 1 for lower memory use.
• --chromatic-aberration-correction: enable correction when supported by the capture metadata; disabled by default.
• --json: write a structured report to stdout for scripts.
• cnefx merge --help: show all options.

Build from source

Requires a C++20 compiler and CMake 3.21+. The build downloads and statically links a pinned LibRaw release.

git clone https://github.com/ChrAlpha/cNEFX.git
cd cNEFX
cmake --preset release
cmake --build --preset release
./build/release/cnefx merge --help

With Visual Studio, the executable is build/release/Release/cnefx.exe. Use the executable's full path or add its directory to PATH for the merge examples above.

Development

See AGENTS.md for the source map, C++ API notes, build checks, packaging and contribution guidelines. Project scope tracks supported behavior and remaining validation gaps. The former Python implementation is available at the v0.0.1 tag.

License

MIT. Distributions also include LibRaw's third-party license files.

Acknowledgements

• Nikon NX Studio, for the reference NEFX outputs used in format research.
• XinmiaoZhao's NikonFirmwarePatch / z8pixelshift, for its pixel-shift reconstruction research and arithmetic reference.