With the option between drawing bounding boxes and polygons, you may wonder: what is the difference between these two annotation types?
Bounding boxes -- boxes drawn around an object of interest in an image -- are easier to draw than polygons, thus taking up less annotation time. Polygons, on the other hand, are more precise, and may lead to a slight increase in performance.
For segmentation tasks, you need to use polygons or masks, since you are training your model to segment specific items from an image with precision. Masks provide the highest fidelity for complex boundaries when you need pixel-perfect control.
This section of the Roboflow documentation shows how to annotate images using each of the above methods.
