1. A method for storing X-ray image data comprising the steps of: producing a series of temporally successive image datasets by pulsed transillumination of an examination subject; producing a first image dataset by averaging a first plurality of said temporally successive X-ray image datasets; storing said first image dataset; producing a second image dataset by averaging a second plurality of said temporally successive X-ray image datasets immediately following said first plurality and allocated to said first image dataset; and storing said second image dataset.