1. A computerized method for interactive non-uniformity correction (NC) and interactive intensity standardization (IS), comprising the steps of: receiving, via a user interface associated with a computing system, a user input indicative of sample tissue regions for several different types of tissues; estimating, by the computing system, a degree of non-uniformity at each voxel in a sample image of the sample tissue regions; building a global function for non-uniformity correction of the sample image; correcting the sample image to improve image quality; using tissue intensity signatures of each sample tissue from a plurality of subjects to set up key landmarks in a standardized intensity space of the corrected sample image; building a piecewise linear intensity mapping function between the same tissue signatures derived from the corrected sample image and those in the standardized intensity space to transform the intensity of the corrected sample image into a standardized intensity; and outputting, based on at least the piecewise linear intensity mapping function and the sample image, an updated image, wherein the updated image is outputted via the user interface or a second user interface associated with the computing system.