NiftiSpy

High-performance NIfTI medical image viewer for VS Code

A blazing-fast NIfTI medical image viewer that runs entirely inside VS Code. Open .nii, .nii.gz, or .hdr files locally or from remote SSH servers — no external tools required.

Features

Installation

1. Install from the VS Code Marketplace (coming soon)
2. Or build from source:

git clone https://github.com/MaiwulanjiangMaiming/NiftiSpy.git
cd NiftiSpy
npm install
npm run build

Then press F5 in VS Code to launch the Extension Development Host.

Usage

1. Open any .nii, .nii.gz, or .hdr file in VS Code
2. The viewer opens automatically as a custom editor
3. Use mouse wheel to scroll slices, drag to pan, Ctrl+Scroll to zoom
4. Click the maximize button (A/C/S/M) on any view to expand it
5. Add a second image via + Add Image to enable comparison modes

Controls

Architecture

VS Code Extension Host
    └── NiiEditorProvider.ts  ──►  LocalFileProxy (HTTP server for remote files)
                                          │
    Webview Panel  ◄──────────────────────┘
        ├── viewer.ts         ──►  Canvas 2D rendering, UI interaction
        ├── worker.ts         ──►  NIfTI parsing, gzip decompression
        └── nii-parser.ts     ──►  Header parsing, orientation detection

Acknowledgments

This project was built upon and inspired by the following open-source projects. We are deeply grateful for their excellent work:

• ITK-SNAP — An open-source software application for segmenting structures in 3D medical images. Our orientation handling, coordinate mapping (voxelToWorld / worldToVoxel), and anatomical direction label logic are based on ITK-SNAP's ImageCoordinateGeometry and GenericSliceModel implementations. Licensed under GPL.

• niivue — A lightweight web-based NIfTI viewer. Our NIfTI parsing approach and webview rendering architecture were inspired by niivue's design. Licensed under BSD-2-Clause.

License

MIT © Maiwulanjiang Maiming