Online Bangla handwritten word recognition using HMM and language model

Abstract

This paper proposes a model which is used to recognize online handwritten Bangla words. This word recognition module comprises of different modules: preprocessing of the word samples, segmentation of words into basic strokes, recognizing the basic strokes using multilayer perceptron, followed by recognition of words using Hidden Markov Model (HMM) aided by Language Model (LM). For stroke recognition, two different feature extraction techniques (point-based and curvature-based procedures) are used using late fusion technique. Top 5 stroke recognition choices are used to construct HMM for the prediction of word sample. An N -gram LM is applied as a post-processing step to rectify the HMM outcomes if required. A total of 50 different word samples with 110 instances each are used to evaluate the proposed model. The overall stroke-level and word-level recognition accuracies obtained by this model are 95.4% and 90.3%, respectively. The proposed model can be extended to recognize online handwritten words written in other script like Devanagari, Assamese, and Gurumukhi, etc. The methodologies described in the manuscript can also be applied for offline word recognition purpose.