1. A method for determining whether illumination problems exist in a digital representation of a document, the method comprising: dividing, using a processor, a tetragon comprising a detected digital representation of a document within the digital image into a plurality of sections, each section comprising a plurality of pixels; determining a distribution of brightness values of each section; determining a brightness value range of each section; determining a variability of brightness values of each section; determining whether each section is oversaturated; determining whether each section is undersaturated; determining a number of oversaturated sections; determining a number of undersaturated sections; determining that the digital image is oversaturated upon determining that a ratio of the number of oversaturated sections to a total number of sections exceeds an oversaturation threshold; determining that the digital image is undersaturated upon determining that a ratio of the number of undersaturated sections to the total number of sections exceeds an undersaturation threshold; and determining that the illumination problem exists in the digital image upon determining that the digital image is either undersaturated or oversaturated.