In this book, the authors present current research in the study of the practices, perspectives and challenges of pattern recognition. Topics include the practical usage of algorithmic probability in pattern recognition; application of pattern recognition in optimisation-simulation techniques; pattern recognition applied to spectroscopy; optimisation of an embedded simplified fuzzy ARTMAP implemented on a microcontroller using MATLAB GUI environment; pattern recognition using quaternion colour moments; and pattern recognition by Bessel mask and one-dimensional signatures.