1. A method for processing a captured image comprising a plurality of sub-blocks of pixels having one or more components, the method comprising: determining, with an image processing device, a first representative value based on first component values of pixels within a portion of interest in the captured image; with the image processing device, determining, for at least one sub-block in the captured image, whether a predetermined minimum number of similar pixels are in the at least one sub-block, a similar pixel having a first component value within a first predetermined threshold of the first representative value; and setting, with the image processing device, the first component value of pixels within the at least one sub-block to a first predetermined value if there is not the predetermined minimum number of similar pixels in the at least one sub-block.