  Machine learning systems based on deep neural networks, being able to produce
state-of-the-art results on various perception tasks, have gained mainstream
adoption in many applications. However, they are shown to be vulnerable to
adversarial example attack, which generates malicious output by adding slight
perturbations to the input. Previous adversarial example crafting methods,
however, use simple metrics to evaluate the distances between the original
examples and the adversarial ones, which could be easily detected by human
eyes. In addition, these attacks are often not robust due to the inevitable
noises and deviation in the physical world. In this work, we present a new
adversarial example attack crafting method, which takes the human perceptual
system into consideration and maximizes the noise tolerance of the crafted
adversarial example. Experimental results demonstrate the efficacy of the
proposed technique.
