Conjoined location and recognition of street names within a postal address delivery line

This paper describes a global model designed to jointly detect and recognize a street name within a delivery line of an handwritten address block image. The model used is based on Hidden Markov Models (HMM). The lines are firstly preprocessed, then segmented and characterized by two types of features. We create a HMM for each street name by simply concatenating the corresponding letter models, elementary HMM learned on a large city name database. A street name may often be surrounded by other information on the left and on the right within the delivery line. These phenomena are roughly modelled by trigrams. The global model is then simply obtained by the concatenation of trigram models with the HMMs corresponding to street names.