“…For brain MR image segmentation, some studies aim to identify the entire image into subregions such as white matter (WM), grey matter (GM), and cerebrospinal fluid spaces (CSF) of the brain (Lim & Pfefferbaum, 1989), whereas others aim to extract one specific structure, for instance, brain tumour (M.C. Clark et al, 1998), multiple sclerosis lesions (Mortazavi et al, 2011), or subcortical structures (Babalola et al, 2008). Due to varying complications in segmenting human cerebral cortex, the manual methods for brain tissues segmentation might easily lead to errors both in accuracy and reproducibility (operator bias), and are exceedingly time-consuming, we thus need fast, accurate and robust semi-automatic (i.e., supervised classification explicitly needs user interaction) or completely automatic (i.e., nonsupervised classification) techniques (Suri, Singh, et al, 2002b).…”