Modeling human color categorization: color discrimination and color memory

Color matching in Content-Based Image Retrieval is done using a color space and measuring distances between colors. Such an approach yields non-intuitive results for the user. We introduce color categories (or focal colors), determine that they are valid, and use them in two experiments. The experiments conducted prove the difference between color categorization by the cognitive processes color discrimination and color memory. In addition, they yield a Color Look-Up Table, which can improve color matching, that can be seen as a model for human color matching

Using Dynamic Time Warping for Intuitive Handwriting Recognition

Contains fulltext : 54957.pdf (publisher's version ) (Open Access)This paper discusses the use of Dynamic Time Warping (DTW) for visually perceptive and intuitive character recognition. In particular in forensic document examination, techniques are required that yield results matching a human user's expectations. In our approach, the goal is to retrieve a set of best matching allographic prototypes based on a query input character. Since DTW compares each pair of closest points from two trajectories, our assumption is that it may resemble most of the pair-wise coordinate comparisons employed by humans. In order to assess our ideas, we have set up a human factors experiment in which two variants of DTW are compared to a state-ofthe- art character classifier, HCLUS. A number of 25 subjects judged the recognition results of these three classifiers for 130 queries. As a result, one particular implementation of DTW was significantly rated as the best system. Future research will combine these promising new findings with techniques that employ other distinctive features like those used by human experts. This research is embedded in the Dutch TRIGRAPH project, which pursues the design of forensic document examination techniques based on expert knowledge.12th IGS conference: 26-29 Jun. 2005, Salerno, Italy. (IGS2005)309 p

Automatic trajectory extraction and validation of scanned handwritten characters

Contains fulltext : 56909.pdf (publisher's version ) (Open Access)A well-established task in forensic writer identification is the comparison of prototypical character shapes (allographs) present in the handwriting. Using elastic matching techniques like Dynamic Time Warping (DTW), comparison results can be made that are plausible and understandable to the human expert. Since these techniques require the dynamics of the handwritten trace, the 'online' dynamic allograph trajectories need to be extracted from the 'offline' scanned documents. We have implemented an algorithm that can automatically extract this information from scanned images. The algorithm makes a list of all possible trajectories. Using a number of traditional techniques and DTW for evaluation, the best trajectory is selected. To be able to make a quantitative assessment of our techniques, rather than a qualitative discussion of a small number of examples, we tested the performance on two large datasets, one containing online and the other containing offline data. Two different methods (one for the online, and one for the offline dataset) are used to validate the generated trajectories. The results of the experiments show that DTW can significantly improve the performance of trajectory extraction when compared to traditional technique

Designing interactive maps for crisis management

Contains fulltext : 55174.pdf (publisher's version ) (Open Access

Dynamic Time Warping Applied to Tamil Character Recognition

Contains fulltext : 56163.pdf (publisher's version ) (Open Access

Platforms for artificial neural networks : neurosimulators and performance prediction of MIMD-parallel systems

In this thesis, two platforms for simulating artificial neural networks are discussed: MIMD-parallel processor systems as an execution platform and neurosimulators as a research and development platform. Because of the parallelism encountered in neural networks, distributed processor systems seem to provide a proper underlying execution platform. The suitability of the class of MIMD-parallel computer platforms (in particular multi-transputer systems) for neural network simulation programs is discussed in this thesis. In order to evaluate the suitability of such systems, a new performance prediction method is presented and evaluated for several classes of neural networks. Neurosimulators provide a platform for simulating, developing, evaluating and executing neural network models. In the last two chapters of this thesis, neurosimulators are examined: environments for the development and simulation of artificial neural networks. By considering their common features, and the requirements of their users, the design criteria for a new neurosimulator are specified. The design, implementation and evaluation of PREENS, an action-oriented neurosimulator is presented in the final chapter

Platforms for artificial neural networks : neurosimulators and performance prediction of MIMD-parallel systems

Contains fulltext : 18657.pdf (publisher's version ) (Open Access)In this thesis, two platforms for simulating artificial neural networks are discussed: MIMD-parallel processor systems as an execution platform and neurosimulators as a research and development platform. Because of the parallelism encountered in neural networks, distributed processor systems seem to provide a proper underlying execution platform. The suitability of the class of MIMD-parallel computer platforms (in particular multi-transputer systems) for neural network simulation programs is discussed in this thesis. In order to evaluate the suitability of such systems, a new performance prediction method is presented and evaluated for several classes of neural networks. Neurosimulators provide a platform for simulating, developing, evaluating and executing neural network models. In the last two chapters of this thesis, neurosimulators are examined: environments for the development and simulation of artificial neural networks. By considering their common features, and the requirements of their users, the design criteria for a new neurosimulator are specified. The design, implementation and evaluation of PREENS, an action-oriented neurosimulator is presented in the final chapter.Promotores : J. Vytopil en T. SchoutenX, 212 p

Mode detection and incremental recognition

Contains fulltext : 64799.pdf (publisher's version ) (Open Access

Mode detection in online pen drawing and handwriting recognition

Contains fulltext : 55436.pdf (publisher's version ) (Open Access