Title :
Supervised image classification by contextual AdaBoost based on posteriors in neighborhoods
Author :
Nishii, Ryuei ; Eguchi, Shinto
Author_Institution :
Fac. of Math., Kyushu Univ., Fukuoka, Japan
Abstract :
AdaBoost, a machine learning technique, is employed for supervised classification of land-cover categories of geostatistical data. We introduce contextual classifiers based on neighboring pixels. First, posterior probabilities are calculated at all pixels. Then, averages of the log posteriors are calculated in different neighborhoods and are then used as contextual classification functions. Weights for the classification functions can be determined by minimizing the empirical risk with multiclass. Finally, a convex combination of classification functions is obtained. The classification is performed by a noniterative maximization procedure. The proposed method is applied to artificial multispectral images and benchmark datasets. The performance of the proposed method is excellent and is similar to the Markov-random-field-based classifier, which requires an iterative maximization procedure.
Keywords :
Bayes methods; Markov processes; geophysical signal processing; geophysical techniques; image classification; image segmentation; learning (artificial intelligence); optimisation; remote sensing; Bayes rule; Markov random field; artificial multispectral images; classification functions; contextual AdaBoost; contextual classifiers; image classification; image segmentation; land cover; log posteriors; machine learning technique; noniterative maximization; posterior probability; Image classification; Image segmentation; Iterative methods; Machine learning; Markov random fields; Mathematics; Multispectral imaging; Pattern recognition; Probability; Voting; Bayes rule; Markov random field (MRF); image segmentation; machine learning; posterior probability;
Journal_Title :
Geoscience and Remote Sensing, IEEE Transactions on
DOI :
10.1109/TGRS.2005.848693