Click two points on the image that span a known distance (e.g. the scale bar).
V Select / moveA Arrow annotationT TextL LineB RectangleE EllipseI Inset boxR Re-renderCtrl+scroll Zoom in/outSpace+drag Pan canvasCtrl+0 Fit to windowCtrl+1 100% zoomCtrl+Z UndoCtrl+Y RedoCtrl+S Save sessionCtrl+E Export PNGDelete Delete selectedEscape Cancel / deselect↑↓←→ Nudge element (1px)Shift+↑↓←→ Nudge 10pxCtrl+A Select all elementsDelete Delete selected elementsShortcuts are inactive while typing in an input field.
Drag to select the region to keep. Corners show at full resolution.