A method for measuring the sensitivity of an image classifier, which assigns an input image to one or multiple classes of a predefined classification, to modifications of the input image. The method includes: the input image is mapped by at least one predefined operator onto an intermediate image, which has a lesser information content and/or a poorer signal-to-noise ratio in comparison to the input image; at least one generator is provided, which is trained to generate realistic images, which image classifier assigns to a specific class of the predefined classification; the generator is used to generate a variation of the input image from the intermediate image.