Viewing

Normal

The default view. Shows a single 2D slice. Scroll to move through slices. h/l changes the scroll dimension; j/k steps one slice at a time.

r rotates 90 degrees or flips the axis. t transposes x and y.

o steps through the three views of a volume (axial → coronal → sagittal), the same planes the multi-view shows. Each view keeps its own r/t rotation and flip. NIfTI views are named and set upright from the file's stored orientation, whatever order it stores its axes in. For arrays without one (e.g. .npy), Shift+A lets you name the current view and give the voxel size, e.g. axial 1 1 3.

When the voxel size is known (NIfTI, or set with Shift+A), images are drawn in their true proportions, so thick slices look tall rather than squashed. a (stretch to square) overrides this.

Multi-view

v — splits the canvas into three orthogonal planes (axial, coronal, sagittal). Drag the crosshair to navigate. Shift+drag for oblique rotation. V opens custom dimension selection; o resets the orientation.

Mosaic

z — lays out a grid of slices along the next dimension. Scrolling then steps through the dimension after that; a plain 3-D volume shows all its slices at once.

Projections

p — cycles through statistical projections along the scroll axis: MAX, MIN, MEAN, STD, SOS.

FFT

f — displays a centered FFT of the array. Prompts for which axes to transform.

RGB

Rendered as direct color via --rgb on the CLI or rgb=True in Python. The first or last dimension must be size 3 (RGB) or 4 (RGBA). No direct keybind — set at launch.

Immersive

Shift+F — fullscreen with all chrome hidden. Move the mouse to briefly reveal controls.

Pop out (VS Code)

Shift+W — moves the VS Code tab into its own window. Press Shift+W again in that window to put the tab back.

Zen mode

Z — hides UI chrome (dimbar, info, island) for a clean view. Press Z again to restore.

Complex data

m — cycles through magnitude, phase, real, and imaginary parts for complex-valued arrays.

qMRI

q — opens qMRI for a parameter dimension. Hold Alt/Option while qMRI is active to choose quantitative parameters and synthesised contrasts. Synthetic contrasts show TE/TR/TI sliders below each pane when available.

Scroll through slices. / opens the tool launcher for ortho, compare, qMRI, ROI, segmentation, FFT, projections, and overlays. The direct keys still work. 0 resets the zoom. ? shows the full key guide.

Caveat

ArrayView works across six invocation environments (CLI, Python script, Jupyter, Julia, VS Code, SSH). Not every feature has been verified in every mode. If something behaves differently than documented, check the remote page for environment-specific notes or open an issue.