1. A method for processing image data, said method comprising determining a set of parameters based on a binary digital image such that said set of parameters comprises information about the density of white and/or black pixels of a first group of pixels of said binary digital image, and information about the density of white and/or black pixels of a second group of pixels of said binary digital image, the information for each of the first group and the second group representing binary image data as continuous tone imagery; wherein said set of parameters comprises information about the distribution of white and/or black pixels in said first group of pixels, and information about the distribution of white and/or black pixels in said second group of pixels; and wherein said set of parameters is arranged in one or more parameter arrays, and the elements of parameter arrays associated with consecutive input images are aligned so as to compensate movement between the consecutive images.