1. An image generation device for generating an image from measured data, wherein image quality is optimized for a region of interest, the image generation device comprising: a noise determination unit ( 31 ) for determining a distribution of noise in a projection domain of the region of interest; and a dose control unit ( 32 ) for determining a dose profile for a radiation source ( 2 ) of said image generation device based on said determined distribution of noise by using a noise propagation algorithm.