  Drones are a versatile platform for both amateur and professional
photographers, enabling them to capture photos that are impossible to shoot
with ground-based cameras. However, when guided by inexperienced pilots, they
have a high incidence of collisions, crashes, and poorly framed photographs.
This paper presents an intelligent user interface for photographing objects
that is robust against navigation errors and reliably collects high quality
photographs. By retaining the human in the loop, our system is faster and more
selective than purely autonomous UAVs that employ simple coverage algorithms.
The intelligent user interface operates in multiple modes, allowing the user to
either directly control the quadcopter or fly in a semi-autonomous mode around
a target object in the environment. To evaluate the interface, users completed
a data set collection task in which they were asked to photograph objects from
multiple views. Our sketchbased control paradigm facilitated task completion,
reduced crashes, and was favorably reviewed by the participants.
