KONVERSI CITRA EKSPRESI MATEMATIKA TERCETAK MENJADI SIMBOL MATEMATIS LATEX MENGGUNAKAN ALGORITMA TEMPLATE MATCHING OPTIMIZED SUM OF ABSOLUTE DIFFERENCE (OSAD); CONVERSION OF PRINTED MATHEMATICAL EXPRESSION INTO LATEX MATHEMATICAL SYMBOL USING OPTIMIZED SUM OF ABSOLUTE DIFFERENCE (OSAD) TEMPLATE MATCHING ALGORITHM

Mahastama, Aditya Wikan, Sri Hartati

2016 | Disertasi | FMIPA

Research on printed mathematical expression recognition is still evolving accordingly to the vast growth of human-machine interaction and the growing need to convert archived scientific documents into electronic documents. The process of recognising printed mathematical expression itself can be divided into two general processes: symbol recognition – which is similar to character recognition and works by segmenting symbols and recognising the result – and structural analysis which reads the structure of the expression, the relation between symbols within the structure, provide adequate labeling to preserve it, and finally be useful to reconstruct the whole expression. This research focused on recognising images of printed mathematical expression, proposing the usage of Optimized Sum of Absolute Difference (OSAD) – a newly proposed image template matching algorithm – as the recognition engine for the symbol recognition process, average face as the matching template, and a novel symbol tree model to preserve the expression structure, on purpose to reconstruct each expression into a sentence of LaTeX mathematical symbols. Results obtained from tests conducted are (1) the accuracy of OSAD is well about 95% on various test images, and 100% for test images used in training phase, (2) the proposed symbol tree is adequate to preserve the structure of expressions, on purpose to rewrite the expressions into another format only. However, these results can only be achieved under a succesful symbol segmentation – which put effect on OSAD’s accuracy to recognise – and a right choice of the expression’s line axis positions – which affects the recognition of the structure and hence the symbol tree labeling accuracy.

Kata Kunci : Pattern recognition, printed mathematical expression recognition, OSAD, symbol tree, expression tree.