METHODS FOR SUPPRESSING STRUCTURED NOISE IN A DIGITAL IMAGE

A method for suppressing structured noise in a digital image includes creating a smoothed version of the original image. Monotonic and slowly-varying image regions are detected by analyzing a residual image which is the function of the original image and its smoothed version. A local window is defined in each pixel location identified in the thresholding process as the location with structured noise and samples inside the window are randomly permuted to randomize the noise structures. A noise-filtered version of the original residual image is generated. The noise-filtered residual and the smoothed version of the original image are combined to produce a final image.