A method for reducing noise in a computed tomographic (CT) image includes
acquiring both a first set of projection views and a second set of
projection views, wherein for each projection view in the first set of
projection views there is an associated projection view in the second set
of projection views representing the same object scanned at substantially
the same time from substantially the same position. The method further
includes reconstructing the first set of projection views and the
associated second set of projection views to obtain a first image and a
second image, respectively. Next, the first image and the second image
are combined to obtain a noise map and an amount of noise in a product
image is estimated utilizing the noise map. The method also includes
filtering using the noise map to perform noise reduction.