Measurement

ROI

A cycles through ROI shapes: rectangle, circle, freehand, flood fill, off.

Active ROIs show live statistics.

For flood fill, [ / ] adjusts tolerance.

u — enter ruler mode. Click two points to measure pixel distance. Press u again to exit.

Hover over the image to see coordinates and value reflected on the colorbar.

Click the colorbar to copy that value to the clipboard.

i — toggle a persistent hover tooltip that follows the cursor.

I — show a data info overlay: shape, dtype, size, file path.

Key	Action
`s`	Screenshot — saved as PNG to Downloads and the snapshot gallery
`g`	GIF along the current slice dimension
`N`	Export current slice as `.npy`
`e`	Copy a reusable URL to clipboard

G toggles the snapshot gallery.