Digital signal processing for image filtering field

Abstract

A processor-implemented method and system of this disclosure are configured to correct or resolve artifacts in a received digital image, using a selection of one or more encompassment measures, each encompassing the largest artifact and an optional second smaller artifact. The processor herein is configured to calculate difference in Gaussians using blurred versions of the input digital image and optionally, the input digital image itself; to composite the resulting difference in Gaussians and the input digital image; and to determine pixels with properties of invariant values, also referred to as invariant pixels. The values in the properties of the invariant pixels are then applied to the artifacts regions to correct these artifacts, thereby generating the modified digital image in which the artifact regions are more or less differentiable to a human eye when compared with the digital image.

What is claimed is: 
     
         1 . A processor-implemented method of processing a digital image to correct artifacts, the processor-implemented method comprising:
 (a) receiving, at a processor from a buffer, a digital image comprising one or more artifact regions;   (b) receiving, at the processor, a first selection of a first encompassment measure that encompasses a largest artifact region of the one or more artifact regions;   (c) blurring, by the processor, a copy of the digital image using the first encompassment measure to generate a first blurred image that is stored in the buffer;   (d) calculating, by the processor,
 i. a first difference of Gaussians of the digital image from the first blurred image 
 ii. a second difference of Gaussians of the first blurred image from the digital image; 
   (e) compositing, by the processor, using the equation C=α*A+(1−α)*B, where α is the first difference of Gaussians, A is the digital image, B is a scaled version of the digital image, and result, C, is a first composited image;   (f) compositing, by the processor, using the equation E=β*C+(1−β)*D, where β is the second difference of Gaussians, D is a scaled version of C and is oppositely scaled than the scaling used for B, and result, E, is a second composited image; and   (g) modifying, by the processor, the digital image, when it is determined that there are one or more pixels of invariable values in a difference image that is generated by a difference of the digital image from the second composited image, wherein the modifying comprises:   scaling one or more values of pixels in each of the one or more artifact regions to within a predefined factor of the invariable values, thereby generating a modified digital image, and wherein a correction to the artifacts in the digital image is provided in the modified digital image.