1. A method of processing an image to reduce artifacts, comprising: applying, in a hardware processing unit, an image filter to an image to extract a level of image detail; dividing the image into blocks of a predetermined size; for each block, measuring a density value associated with the level of image detail, wherein measuring the density value associated with the level of image detail comprises using greyscale values associated with the image to calculate a block score indicative of the level of image detail for the block; for blocks wherein the density value exceeds a threshold amount, applying an increasing degree of blur to each block based on an increasing density value, wherein the degree of blur varies between blocks and wherein no blur is applied for blocks having a density value below the threshold amount; and outputting the image such that only some of the blocks of the image are blurred while other blocks do not have blur applied; wherein some of the blurred blocks are not output to the image.