2D Instance Segmentation

Annotating instance segmentation involves drawing polygons. Simply click on the image to start a label, and close the path to finish drawing. Click on the boundary to select the label.

Dragging the midpoint on an edge turns the midpoint into a vertex. Click the midpoint of an edge while pressing c makes the edge a bezier curve. You can adjust the control points to get tight-fitting curves. To revert back to a normal edge, click on a control point while pressing c.


Drawing a segmentation label

Sometimes an instance can be divided into multiple parts in the image due to occlusion. To link different polygons, first press Ctrl (Cmd) to select polygons you want to link, then press l (lowercase) to link these selected polygons. Press L (uppercase) to unlink the label.


Linking and unlinking segmentation labels

We also support vertex deletion. To delete a vertex from a drawn polygon, press d first, and then click on the control point you want to delete. The second way to use vertex deletion is when drawing a new polygon. When the drawing is not finished, press d could delete previous drawn vertex.


Deleting vertex

Lane Marking

Lane marking is similar to segmentation labeling, except that the path is not closed. Hit Enter to finish drawing a label.


Lane marking

Drivable Area

Similarly as other instance segmentation tasks, you can annotate the drivable area in the image. Details about the drivable area can be found in this blog.