Grapheme Based Writer Verification

In this communication we propose an approach for the writer verification task. The difficulty of this task lies first, in the decision making between the two assumptions which model the problem: "Do the two writings come from the same writer ?" or "Do the two writings come from different writers?" and second, in the evaluation of the error risk associated to this decision. We have called upon a mutual information based hypothesis test for the evaluation of these errors taking into account the distribution of the two assumptions (within-writer distribution and between-writer distribution) on a sample set of 88 writers. Features used for this writer verification problem are graphemes produced by a segmentation module. This verification process is intended to confirm or reject the writer candidates proposed by a writer identification system