In addition to generating an exact targeted caption by perturbing the input image, we offer an intermediate option that aims at generating captions with specific keywords, denoted by K : Intuitively, finding an adversarial image generating a caption with specific keywords might be easier than generating an exact caption, as we allow more degree of freedom in caption generation.
to the best of our knowledge, this is the very first work on crafting adversarial examples for neural image captioning systems.