1. An image generation device for generating an image from measured data generated by an imaging system, wherein the imaging system includes a radiation source and a power supply for the radiation source, and wherein an image quality of the image is optimized for a region of interest in the image, the image generation device comprising: a noise determination unit that determines, in a projection domain, an expected distribution of noise of individual projections of second data for the region of interest; a dose control unit that determines a dose profile for the region of interest based on said determined distribution of noise of the individual projections using a noise propagation algorithm; wherein the dose control unit controls the power supply based on the dose profile so as to control a radiation intensity generated by the radiation source during tomographic imaging, with the imaging system, that generates the measured data; and an image generation unit that processes the measured data and generates the image from the measured data.