Template-based Nepali Natural Handwritten Alphanumeric Character Recognition
KC Santosh, Cholwich Nattee · Thammasat International Journal of Science and Technology · 2007
In this paper, we explore the efficacy of various stroke-based handwriting analysis strategies in classifring Nepalese handwritten alphanumeric characters by using a template-based approach. Writing units are variable from time to time, even within the drawings of a specific character from the same user. Writing units include the properties of stroke such as, number, shape and size, order and writing speed. We propose to use structural properties of writing samples having such variability in writing units. We employ a Dynamic Time Warping (DTW) algorithm to align two on-line handwritten strokes and to estimate the similarity. We use two different features for stroke identification, a sequence of direction at every pen-tip position along the pen trajectory and inclusion of pen-tip position with the direction as the feature of the stroke. For each fype of feature, two different systems are trained by using both original and pre-processed samples. To evaluate the system, we collected examples of 46 different alphanumeric characters from 25 Nepalese natives, and then performed a series ofdifferent experiments. Use ofspecific-stroke pre-processing and a sequence of both pen-tip position and slope at every position as a feature of a stroke, yield improved results, which are confidently supported by a five-fold cross validation. The superiority of the present work over several related works on Devanagari script, is the recognition ofstroke number and stroke order free natural handwritten alphanumeric characters.