  Recent advancements of neural networks lead to reliable monocular depth
estimation. Monocular depth estimated techniques have the upper hand over
traditional depth estimation techniques as it only needs one image during
inference. Depth estimation is one of the essential tasks in robotics, and
monocular depth estimation has a wide variety of safety-critical applications
like in self-driving cars and surgical devices. Thus, the robustness of such
techniques is very crucial. It has been shown in recent works that these deep
neural networks are highly vulnerable to adversarial samples for tasks like
classification, detection and segmentation. These adversarial samples can
completely ruin the output of the system, making their credibility in real-time
deployment questionable. In this paper, we investigate the robustness of the
most state-of-the-art monocular depth estimation networks against adversarial
attacks. Our experiments show that tiny perturbations on an image that are
invisible to the naked eye (perturbation attack) and corruption less than about
1% of an image (patch attack) can affect the depth estimation drastically. We
introduce a novel deep feature annihilation loss that corrupts the hidden
feature space representation forcing the decoder of the network to output poor
depth maps. The white-box and black-box test compliments the effectiveness of
the proposed attack. We also perform adversarial example transferability tests,
mainly cross-data transferability.
