Abstract: For the purpose of providing an image processing method for determining the variance of noise in an image, a residual sum of squares of pixel values is determined for each of a plurality of local regions defined over the entire image (502-508); a histogram thereof is obtained (510); and the variance of noise is determined based on the value of the residual sum of squares that gives a peak of the histogram (512, 514).

Abstract: A method for MRI signal analysis of an area of a biological tissue comprising: a) providing a biological tissue, wherein physiological activity is taking place in an area thereof; b) acquiring sequential magnetic resonance images, at least during a portion of time in which said physiological activity is taking place, of said area and of at least a portion of the tissue in a vicinity of the area; c) constructing, responsive to at least one pixel-related parameter value of said images, a pixel parameter space; and d) separating the pixel parameter space into at least two subspaces.