1,106 research outputs found
Robust Brain MRI Image Classification with SIBOW-SVM
The majority of primary Central Nervous System (CNS) tumors in the brain are
among the most aggressive diseases affecting humans. Early detection of brain
tumor types, whether benign or malignant, glial or non-glial, is critical for
cancer prevention and treatment, ultimately improving human life expectancy.
Magnetic Resonance Imaging (MRI) stands as the most effective technique to
detect brain tumors by generating comprehensive brain images through scans.
However, human examination can be error-prone and inefficient due to the
complexity, size, and location variability of brain tumors. Recently, automated
classification techniques using machine learning (ML) methods, such as
Convolutional Neural Network (CNN), have demonstrated significantly higher
accuracy than manual screening, while maintaining low computational costs.
Nonetheless, deep learning-based image classification methods, including CNN,
face challenges in estimating class probabilities without proper model
calibration. In this paper, we propose a novel brain tumor image classification
method, called SIBOW-SVM, which integrates the Bag-of-Features (BoF) model with
SIFT feature extraction and weighted Support Vector Machines (wSVMs). This new
approach effectively captures hidden image features, enabling the
differentiation of various tumor types and accurate label predictions.
Additionally, the SIBOW-SVM is able to estimate the probabilities of images
belonging to each class, thereby providing high-confidence classification
decisions. We have also developed scalable and parallelable algorithms to
facilitate the practical implementation of SIBOW-SVM for massive images. As a
benchmark, we apply the SIBOW-SVM to a public data set of brain tumor MRI
images containing four classes: glioma, meningioma, pituitary, and normal. Our
results show that the new method outperforms state-of-the-art methods,
including CNN
Uncertainty Analysis for the Classification of Multispectral Satellite Images Using SVMs and SOMs
Abstract: Classification of multispectral remotely sensed data with textural features is investigated with a special focus on uncertainty analysis in the produced land-cover maps. Much effort has already been directed into the research of satisfactory accuracy-assessment techniques in image classification, but a common approach is not yet universally adopted. We look at the relationship between hard accuracy and the uncertainty on the produced answers, introducing two measures based on maximum probability and a quadratic entropy. Their impact differs depending on the type of classifier. In this paper, we deal with two different classification strategies, based on support vector machines (SVMs) and Kohonen's self-organizingmaps (SOMs), both suitably modified to give soft answers. Once the multiclass probability answer vector is available for each pixel in the image, we studied the behavior of the overall classification accuracy as a function of the uncertainty associated with each vector, given a hard-labeled test set. The experimental results show that the SVM with one-versus-one architecture and linear kernel clearly outperforms the other supervised approaches in terms of overall accuracy. On the other hand, our analysis reveals that the proposed SOM-based classifier, despite its unsupervised learning procedure, is able to provide soft answers which are the best candidates for a fusion with supervised results
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