1. A digital imaging file processing system for processing and filing digitized documents comprising: scanner means for scanning and converting a group of input documents into digital image data; storage means for storing digital image data; and detection means for detecting highlighted areas on the input documents, said detection means further comprising: first illumination means for illuminating said input documents with light of a first illumination quality; second illumination means for illuminating said input documents with light of a second illumination quality; output comparison means which obtains a comparison value from comparing, at each predefined cell of pixels, the difference of potential output of the first illumination means with the difference of potential output of the second illumination means; and thresholding means for thresholding at each cell, the result of said output comparison means and determining the presence of highlighting in the cell if the comparison value is greater than or equal to a predefined threshold value, while determining the non-presence of highlighting in the cell if the comparison value is less than the predefined threshold value.