Temporally Smooth Privacy-Protected Airborne Videos

Recreational videography from small drones can capture bystanders who may be uncomfortable about appearing in those videos. Existing privacy filters, such as scrambling and hopping blur, address this issue through de-identification but generate temporal distortions that manifest themselves as flicker. To address this problem, we present a robust spatiotemporal hopping blur filter that protects privacy through de-identification of face regions. The proposed filter is meant for on-board installation and produces temporally smooth and pleasant videos. We apply hopping blur to protect each frame against identification attacks, and minimise artefacts and flicker introduced by the hopping blur. We evaluate the proposed filter against different identification attacks and by assessing the quality of the resulting videos using a subjective test and objective measures.