To draw a polygon, press Enter or New object (shortcut N). The following click will start a new object. Add or move a vertice by selecting a polygon and clicking Edit (shortcut E). To move a vertex click on it and drag. You can add a new vetice by clicking the projection of a new vertex when close to the border of an image.
Create a new separate polygon by pressing New polygon in group (shortcut G) which will then be part of the same object. This is handy for labeling multipart objects.
To create a hole click New hole (shortcut H) which can be edited just like polygons. Parts of the image covered by polygons are not part of the object the hole belongs too.
Polylines are a selection of points connected by lines, useful for labeling parts that are defined by structure and not the exact shape.
To draw a polyline, press Enter or New object (shortcut N). The following click will start a new object. Points can be moved by selecting the polyline and clicking Edit (shortcut E). To Add points click Add points (shortcut K), the new point will be connected to the previous. To remove points click on a specific one and Press Remove points (shortcut R). The polyline will redraw itself, remaining connected.
A bitmap is a freeform hand-drawn mask used to label objects that are complex in shape.
Bitmaps are drawn with a paint-like brush and do not have to be connected in any way to form an object. To draw a bitmap, press Enter or New object (shortcut N). The following click will start a new object. To add an existing bitmap, select and press Draw (shortcut E). To change from a brush to the eraser, select a bitmap and press Erase (shortcut R). To fill the mask so that it becomes solid, Press Fill (shortcut G) and click inside the closed bitmap shape.