Annotation Tools
One tool is active at a time; pick it in the left toolbar or by shortcut. The new shape is assigned the active label (switch with Ctrl+1…0 or in the Labels tab).
Rules that apply to all drawing tools:
- Right-click removes the last placed vertex, or cancels the shape when none are left.
- N finishes a multi-point shape; Esc cancels the operation.
- Ctrl+Shift+N discards the shape being drawn and restarts it.
- Canvas navigation stays live while drawing: wheel zooms, middle-drag / Space-drag pans.
Select — V
Section titled “Select — V”The default tool: click to select, drag to move, and every editing operation described in Editing shapes.
Pan — H and Zoom — Z
Section titled “Pan — H and Zoom — Z”Pan drags the viewport. The Zoom tool lets you drag a rectangle to zoom exactly into that region — faster than wheel-zooming when you want a specific grain filling the screen. F fits the image to the window at any time.
Rectangle — R
Section titled “Rectangle — R”Press and drag; release to create the box.
Ellipse — E
Section titled “Ellipse — E”Same drag interaction as Rectangle. Both rectangles and ellipses support rotation after creation.
Polygon — P
Section titled “Polygon — P”The workhorse for grain and phase boundaries.
- Click to place vertices one by one; a live preview follows the cursor.
- Right-click to remove the last vertex if you misclick.
- Press N to close the polygon (needs at least 3 vertices).
Polyline — L
Section titled “Polyline — L”Open paths for cracks, fibers, linear features. Same click-per-vertex flow as Polygon, finished with N (needs at least 2 vertices).
Note that L is context-sensitive: with an object selected it toggles that object’s lock instead of switching tools — press Esc or click empty canvas to deselect first.
Point — O
Section titled “Point — O”Single click, single marker — for counting workflows. Every click creates a point annotation with the active label.
Mask brush
Section titled “Mask brush”Paints a pixel mask instead of a vector outline — the right choice when a region is too irregular for polygon vertices. Drag to paint with an adjustable round brush; masks are stored as compact RLE bitmaps (see data format).
Cuts an existing shape in two:
- Click the shape you want to cut.
- Click on its boundary to start the cut line, optionally place intermediate points, and finish on another boundary point.
- The shape is split into two annotations along that line.
Attaches image-level labels — batch names, quality flags, workflow states — to the whole image rather than to a region.
AI interactive segmentation — Ctrl+Shift+A
Section titled “AI interactive segmentation — Ctrl+Shift+A”Click-to-segment with a local model. Covered in AI segmentation.