1. A method for registering two-dimensional image data, comprising: providing a three-dimensional image data set of an object under examination, said three-dimensional image data set registered to the object; providing a two-dimensional image data set of the object under examination which is to be registered; generating, using a processor, a plurality of synthetic two-dimensional image data sets of the object under examination from the three-dimensional image data set, wherein each of the generated synthetic two-dimensional image data sets is parameterized with regard to parameters corresponding to recording conditions of a virtual image capture device; comparing, using a processor, each of the plurality of parameterized synthetic two-dimensional image data sets with the two-dimensional image data set, and finding a parameterized synthetic two-dimensional image data set of the plurality of parameterized two-dimensional image data sets having the greatest similarity to the two-dimensional image data set; based on the synthetic two-dimensional image data set having the greatest similarity with the two-dimensional image data set, ascertaining the spatial relationship between the two-dimensional image data set and the registered three-dimensional image data set, thereby registering the two-dimensional image data set to the three-dimensional image data set.