A method, system, and computer program product of detecting defects in an object using a processor operatively connected to a memory, the method comprising: accommodating in the memory an image group comprising a reference image and an image; generating a set of correction parameters to be applied to pixels of an image from the image group, wherein the parameters are determined to minimize a combination of a first factor indicative of variability of the set, and a second factor indicative of a difference between an image from the image group as enhanced by applying the set and another image in the image group, wherein the combination increases as any factor increases; applying the set to the image of the image group to obtain an enhanced image; generating an optimal difference image between the enhanced image and the other image; and using the optimal difference image for detecting defect candidates.