In pictures: A bird's eye view

The winners of this year's aerial photography competition run by online site Dronestagram have been announced. There were thousand of entries taken using drone cameras and the winners were selected by the judges - National Geographic deputy director Patrick Witty and Emanuela Ascoli, photo editor of National Geographic France - and Dronestagram's team. Here we present the winning images from the four categories. This year there was a special category to recognise the creativity of the Dronestagram community.