<title>A generic method for structure recognition of handwritten mail documents</title>

Abstract

This paper presents a system to extract the logical structure of handwritten mail documents. It consists in two joined tasks: the segmentation of documents into blocks and the labeling of such blocks. The main considered label classes are: addressee details, sender details, date, subject, text body, signature. This work has to face with difficulties of unconstrained handwritten documents: variable structure and writing.We propose a method based on a geometric analysis of the arrangement of elements in the document. We give a description of the document using a two-dimension grammatical formalism, which makes it possible to easily introduce knowledge on mail into a generic parser. Our grammatical parser is LL(k), which means several combinations are tried before extracting the good one. The main interest of this approach is that we can deal with low structured documents. Moreover, as the segmentation into blocks often depends on the associated classes, our method is able to retry a different segmentation until labeling succeeds.We validated this method in the context of the French national project RIMES, which proposed a contest on a large base of documents. We obtain a recognition rate of 91.7% on 1150 images.

Results of the RIMES Evaluation Campaign for Handwritten Mail Processing

“…-The second system proposed by IRISA Rennes is based on the DMOS method and uses a grammatical EPF language to define some rules supposed to be at the heart of the letter layout [3].…”

LearnPos: a new tool for interactive learning positioning

“…Adapting an existing grammar A grammatical description for the RIMES evaluation campaign already existed, this grammar was presented by Lemaitre. 13 In this existing grammar, position operator parameters were manually defined. We generated position operators with LearnPos for this grammar and introduced our inferred position operator in the existing deterministic grammar.…”