1. A method of characterizing a word image comprising: traversing the word image stepwise with a window to provide a plurality of window images; for each of the plurality of window images: splitting the window image to provide a plurality of cells, wherein when only a portion of the window image contains active pixels, the splitting comprises splitting only a rectangular area in the window image containing the active pixels into an array of cells, whereby a portion of the window image containing no active pixels is excluded from the splitting; extracting a feature from each of the plurality of cells, the feature comprising a gradient orientation histogram; and characterizing the word image based on the features extracted from the plurality of window images; and wherein the method is performed using a computer or processor.