Figures. List of Tables. Preface. Acknowledgments. Acronyms. 1. Introduction: Character Recognition, Evolution and Development. 1.1 Generation and Recognition of Characters. 1.2 History of OCR. 1.3 Development of New Techniques. 1.4 Recent Trends and Movements. 1.5 Organization of the Remaining Chapters. References. 2. Tools for Image Pre-Processing. 2.1 Generic Form Processing System. 2.2 A Stroke Model for Complex Background Elimination. 2.2.1 Global Gray Level Thresholding. 2.2.2 Local Gray Level Thresholding. 2.2.3 Local Feature Thresholding-Stroke Based Model. 2.2.4 Choosing the Most Efficient Character Extraction Method. 2.2.5 Cleaning up Form Items Using Stroke Based Model. 2.3 A Scale-Space Approach for Visual Data Extraction. 2.3.1 Image Regularization. 2.3.2 Data Extraction. 2.3.3 Concluding Remarks. 2.4 Data Pre-Processing. 2.4.1 Smoothing and Noise Removal. 2.4.2 Skew Detection and Correction. 2.4.3 Slant Correction. 2.4.4 Character Normalization. 2.4.5 Contour Tracing/Analysis. 2.4.6 Thinning. 2.5 Chapter Summary. References 72. 3. Feature Extraction, Selection and Creation. 3.1 Feature Extraction. 3.1.1 Moments. 3.1.2 Histogram. 3.1.3 Direction Features. 3.1.4 Image Registration. 3.1.5 Hough Transform. 3.1.6 Line-Based Representation. 3.1.7 Fourier Descriptors. 3.1.8 Shape Approximation. 3.1.9 Topological Features. 3.1.10 Linear Transforms. 3.1.11 Kernels. 3.2 Feature Selection for Pattern Classification. 3.2.1 Review of Feature Selection Methods. 3.3 Feature Creation for Pattern Classification. 3.3.1 Categories of Feature Creation. 3.3.2 Review of Feature Creation Methods. 3.3.3 Future Trends. 3.4 Chapter Summary. References. 4. Pattern Classification Methods. 4.1 Overview of Classification Methods. 4.2 Statistical Methods. 4.2.1 Bayes Decision Theory. 4.2.2 Parametric Methods. 4.2.3 Non-ParametricMethods. 4.3 Artificial Neural Networks. 4.3.1 Single-Layer Neural Network. 4.3.2 Multilayer Perceptron. 4.3.3 Radial Basis Function Network. 4.3.4 Polynomial Network. 4.3.5 Unsupervised Learning. 4.3.6 Learning Vector Quantization. 4.4 Support Vector Machines. 4.4.1 Maximal Margin Classifier. 4.4.2 Soft Margin and Kernels. 4.4.3 Implementation Issues. 4.5 Structural Pattern Recognition. 4.5.1 Attributed String Matching. 4.5.2 Attributed Graph Matching. 4.6 Combining Multiple Classifiers. 4.6.1 Problem Formulation. 4.6.2 Combining Discrete Outputs. 4.6.3 Combining Continuous Outputs. 4.6.4 Dynamic Classifier Selection. 4.6.5 Ensemble Generation. 4.7 A Concrete Example. 4.8 Chapter Summary. References. 5. Word and String Recognition. 5.1 Introduction. 5.2 Character Segmentation. 5.2.1 Overview of Dissection Techniques. 5.2.2 Segmentation of Handwritten Digits. 5.3 Classification-Based String Recognition. 5.3.1 String Classification Model. 5.3.2 Classifier Design for String Recognition. 5.3.3 Search Strategies. 5.3.4 Strategies for Large Vocabulary. 5.4 HMM-Based Recognition. 5.4.1 Introduction to HMMs. 5.4.2 Theory and Implementation. 5.4.3 Application of HMMs to Text Recognition. 5.4.4 Implementation Issues. 5.4.5 Techniques for Improving HMMs' Performance. 5.4.6 Summary to HMM-Based Recognition. 5.5 Holistic Methods For Handwritten Word Recognition. 5.5.1 Introduction to Holistic Methods. 5.5.2 Overview of Holistic Methods. 5.5.3 Summary to Holistic Methods. 5.6 Chapter Summary. References. 6. Case Studies. 6.1 Automatically Generating Pattern Recognizers with Evolutionary Computation. 6.1.1 Motivation. 6.1.2 Introduction. 6.1.3 Hunters and Prey. 6.1.4 Genetic Algorithm. 6.1.5 Experiments. 6.1.6 Analysis. 6.1.7 Future Directions. 6.2 Offline Handwritten Chinese Character Recognition. 6.2.1 Related Works. 6.2.2 System Overview. 6.2.3 Character Normalization. 6.2.4 Direction Feature Extraction. 6.2.5 Classification Methods. 6.2.6 Experiments. 6.2.7 Concluding Remarks. 6.3 Segmentation and Recognition of Handwritten Dates on Canadian Bank Cheques. 6.3.1 Introduction. 6.3.2 System Architecture. 6.3.3 Date Image Segmentation. 6.3.4 Date Image Recognition. 6.3.5 Experimental Results. 6.3.6 Concluding Remarks. References.

Character Recognition Systems: A Guide for Students and Practitioners

This paper presents a system that extracts 109 musical features from symbolic recordings (MIDI, in this case) and uses them to classify the recordings by genre. The features used here are based on instrumentation, texture, rhythm, dynamics, pitch statistics, melody and chords. The classification is performed hierarchically using different sets of features at different levels of the hierarchy. Which features are used at each level, and their relative weightings, are determined using genetic algorithms. Classification is performed using a novel ensemble of feedforward neural networks and k-nearest neighbour classifiers. Arguments are presented emphasizing the importance of using high-level musical features, something that has been largely neglected in automatic classification systems to date in favour of low-level features. The effect on classification performance of varying the number of candidate features is examined in order to empirically demonstrate the importance of using a large variety of musically meaningful features. Two differently sized hierarchies are used in order to test the performance of the system under different conditions. Very encouraging classification success rates of 98% for root genres and 90% for leaf genres are obtained for a hierarchical taxonomy consisting of 9 leaf genres.

/pdf/automatic-genre-classification-using-large-high-level-4z6le6mhrg.pdf

Automatic Genre Classification Using Large High-Level Musical Feature Sets.

Genetic algorithms (GAs) are a tool used to solve high-complexity computational problems. Apart from modelling the phenomena occurring in Nature, they help in optimization, simulation, modelling, design and prediction purposes in science, medicine, technology, and everyday life. They can be adapted to the given task, be joined with other ones (this leads to combined or hybrid methods), and can work in parallel on many processors. The uses of GAs reported in literature represent a wide variety of approaches and led to solving of numerous computational problems of high complexity. In materials science and related fields of science and technology the GAs open possibilities for materials design, studies of their properties, or production at industrial scale. Here, the recent use of GAs in various domains connected to materials science, solid state physics and chemistry, crystallography, biology, and engineering is reviewed. The listed examples taken from recent literature show how broad the use of these metho...

Genetic Algorithms, a Nature-Inspired Tool: Survey of Applications in Materials Science and Related Fields

Feature-level fusion approaches based on multimodal EEG data for depression recognition

Stability (robustness) of feature selection methods is a topic of recent interest, yet often neglected importance, with direct impact on the reliability of machine learning systems. We investigate the problem of evaluating the stability of feature selection processes yielding subsets of varying size. We introduce several novel feature selection stability measures and adjust some existing measures in a unifying framework that offers broad insight into the stability problem. We study in detail the properties of considered measures and demonstrate on various examples what information about the feature selection process can be gained. We also introduce an alternative approach to feature selection evaluation in the form of measures that enable comparing the similarity of two feature selection processes. These measures enable comparing, e.g., the output of two feature selection methods or two runs of one method with different parameters. The information obtained using the considered stability and similarity measures is shown to be usable for assessing feature selection methods (or criteria) as such.

Evaluating Stability and Comparing Output of Feature Selectors that Optimize Feature Subset Cardinality

Our aim is: a) to present a comprehensive survey of previous attempts at using genetic algorithms (GA) for feature selection in pattern recognition applications, with a special focus on character recognition; and b) to report on work that uses GA to optimize the weights of the classification module of a character recognition system. The main purpose of feature selection is to reduce the number of features, by eliminating irrelevant and redundant features, while simultaneously maintaining or enhancing classification accuracy. Many search algorithms have been used for feature selection. Among those, GA have proven to be an effective computational method, especially in situations where the search space is uncharacterized (mathematically), not fully understood, or/and highly dimensional.

F. Hussein

Papers

Genetic algorithms for feature selection and weighting, a review and study