1. A method of applying an array of anisotropic filters for image scale-space analysis, the method comprising: forming an array of elliptic-shaped anisotropic filters with a first scale parameter in the x direction (s x ) and a second scale parameter in the y direction (s y ) as scale parameters (s x , s y ), wherein the s x and the s y scale parameters are separately varied to provide accurate region characterization; analyzing scale space for a selected frame by the array of elliptic-shaped anisotropic filters of finite spatial support corresponding to selected different values of the (s x ) and (s y ) scale parameters; computing a Hessian determinant response image for each elliptic-shaped anisotropic filter of finite spatial support corresponding to selected pairs (s x , s y ) of scale parameters; and determining a set of local maxima in contiguous 4-dimensional scale-space volumes of the Hessian determinant response images with coordinates (x, y, s x , s y ).