Alternative Noise Map Estimation Methods for CT Images

In this work, we propose three alternative methods to estimate noise map for CT images. Our methods are generalizations to the existing even-and-odd views approach proposed by Hsieh and Thibault [1]. Method one in this work estimates noise map from images reconstructed from three sets of independent views. Method two deals with images reconstructed by using two sets of correlated views. Our method three generates the noise map from two images reconstructed from two sets of independent views while the number of views in each set is unequal. Physical phantom data were employed to validate our proposed noise map estimation methods. In comparison to the existing method, our alternative methods yield reasonably accurate noise map estimation