An image system, notably an X-ray system and an ultrasound system, is provided in which images or sequences of images are generated and used to automatically change or optimize the operational behavior of individual image system components. Measurement fields are defined in the images of an image sequence by means of a data processing unit. Information is extracted from the measurement fields in order to adapt the system components. More specifically, in the course of a sequence of images the measurement fields are adapted or shifted in conformity with the motion of objects.