In this paper, we propose a robust unsupervised change detection algorithm for multilook polarimetric synthetic aperture radar (PolSAR) data. The Hotelling-Lawley trace (HLT) statistic is used as a test statistic to measure the similarity of two covariance matrices. The generalized Kittler and Illingworth (K&I) minimum-error thresholding algorithm is then applied on the test statistic image to ...

We develop an asymptotic likelihood ratio test for multivariate lognormal data with a point mass at zero in each dimension. The test generalizes Wilks' lambda and Hotelling T-test to the case of semicontinuous data. Simulations show that the resulting test statistic attains the nominal Type I error rate and has good power for reasonable alternatives. We conclude with an application to explorati...

UNLABELLED Attenuation, photon scatter, and distance-dependent collimator-detector response are major degrading factors in myocardial SPECT images. The current study investigated whether compensation for these factors improves perfusion defect detectability, and compared the results for human observers with a previous study using a mathematical observer. METHODS Four methods were investigated...

This paper presents a theoretical development that extends results on the distribution of the sample correlation coefficient and the Fisher transform (Fisher, 1921). Several well known correlational procedures use the Fisher transform or its square as the basis of hypothesis testing. These procedures assume that the variance of the Fisher transform can be approximated adequately as 1/( 3) n − ....