1. A method for detecting handwritten annotations from a scanned document image, the scanned document image having a handwritten annotation and at least one printed text line, the method comprising the steps of: generating at least one projection histogram for the scanned document image, wherein the projection histogram includes a regular pattern that correlates to the printed text lines; applying connected component analysis to the scanned document image in order to generate at least one merged text line, wherein each of the merged text lines correlate to at least one of the handwritten annotations and the printed text line; and comparing the merged text lines to the regular pattern of the projection histograms, thereby discriminating the printed text lines from the handwritten annotations.