Image based Wheel Detection using Random Forest Classification

Sammanfattning: The aim of this master thesis is to detect and recognise wheels in images by means of image analysis. This could later on serve as a foundation for a safer vehicle counting and classification method than those currently in use that requires personnel to cross the lanes on installation. The general layout of the classification system consists of five stages: multi-scale transformation, window extractor, pre-processing, classification and cluster analysis. In order to obtain the training and testing data for evaluation and construction of the system, images that illustrate moving cars on a road are acquired. From these, several positive and negative windows are extracted that visualizes wheels and non-wheels. For the classification stage, the learning algorithm used is Random Forest. Moreover, with the Random Forest as the foundation, two different concepts were introduced to further improve the predictions. These are referred to as bootstrap configuration and cascading classification. The results are evaluated be means of Receiver Operating Characteristics and contingency tables. In this master thesis, the final system produces a satisfying result based on the false positive rate and true positive rate. For future development, the amount of examples in the training data could be increased in order to gain more knowledge in the teaching of the classifier. Furthermore, an optimization of the program could lead to faster execution time, which is a requirement if this system is to operate in real-time. To conclude, the system produces a satisfying result for wheel detection that can be used as a foundation when constructing a general system for vehicle counting and classification.