1. An apparatus for reducing the gray scale resolution of a document comprising: means for scanning said document along x and y coordinates with regard thereto for generating pixels representing gray scale values for discrete areas of said document along said x and y coordinates; each said pixel having a predetermined number of binary bits; means for summing the associated pixels within a matrix of said pixels along said x and y coordinates, with said matrix being hereinafter referred to as a window to produce a window sum as said window is moved relatively along coordinates corresponding to said x and y coordinates; and means for comparing a selected pixel within a said window with the associated said window sum and predetermined criteria and for generating first and second outputs in accordance with said comprising; said first and second output values having fewer binary bits than the associated said selected pixel.