1. A method, comprising: obtaining de-noised reconstructed tomographic image data; generating noisy edge image data by multiplying noise image data and an edge map, wherein the noise image data represents noise removed from reconstructed tomographic image data used to generate the de-noised reconstructed tomographic image data; weighting the noisy edge image data with a predetermined weight by multiplying the noisy edge image data by the weight; and adding the weighted noisy edge image data to the de-noised reconstructed tomographic image data, which edge improves a sub-set of the de-noised reconstructed tomographic image data corresponding to edges of structure represented in the de-noised reconstructed tomographic image data.