Ablation Path Saliency

Various types of saliency methods have been proposed for explaining black-box classification. In image applications, this means highlighting the part of the image that is most relevant for the current decision. We observe that several of these methods can be seen as edge cases of a single, more general procedure based on finding a particular ablation path through the classifier's domain. This gives additional geometric insight to the existing methods. We also demonstrate that this ablation path method can be used as a technique in its own right, the higher computational cost being traded against additional information given by the path.