Feature selection and extraction plays an important role in different
classification based problems such as face recognition, signature verification,
optical character recognition (OCR) etc. The performance of OCR highly depends
on the proper selection and extraction of feature set. In this paper, we
present novel features based on the topography of a character as visible from
different viewing directions on a 2D plane. By topography of a character we
mean the structural features of the strokes and their spatial relations. In
this work we develop topographic features of strokes visible with respect to
views from different directions (e.g. North, South, East, and West). We
consider three types of topographic features: closed region, convexity of
strokes, and straight line strokes. These features are represented as a
shape-based graph which acts as an invariant feature set for discriminating
very similar type characters efficiently. We have tested the proposed method on
printed and handwritten Bengali and Hindi character images. Initial results
demonstrate the efficacy of our approach