PEDRO, Ricardo Wandré Dias. Inference of stochastic grammars for pattern recognition in images using quadtrees. 2013. 132 p. Dissertation (Master of Science) -School of Arts, Sciences and Humanities, University of São Paulo, São Paulo, 2013. In the last decade syntactic methods have been widely used for pattern recognition in images. A systematic review on this subject indicated that there are works about the usage of grammars for recognizing specific objects in images, recognition of textures,

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... construction of objects, image segmentation, image scaling, and recognition of layouts in documents. It was noticed that only some of the analyzed studies showed methods of grammatical inference. Perceived this gap, this study aimed to evaluate the usage of stochastic grammars inferred from training samples containing structures of quadtrees of images in image classification problem. To achieve this goal it was used and adapted two algorithms for grammatical inference and one algorithm of probability estimation responsible for transforming the inferred context-free grammars in stochastic context-free grammars. The results show that the proposed techniques can be used in the classification of geometric figures. However, although the performance with quadtrees has not been excellent, it was clear that the use of grammars can be an interesting approach for image classification.