1. A method of image scale-space analysis that applies an array of anisotropic filters for interest region determination, the method comprising: forming an array of elliptic-shaped anisotropic second order partial derivative Gaussian 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 ); forming an array of rectangular-shaped anisotropic second order partial derivative Gaussian filters with finite spatial support according to the (s x , s y ) scale parameters to approximate the elliptic-shaped anisotropic second order partial derivative Gaussian filters; analyzing scale space for a selected image frame by the array of rectangular-shaped anisotropic second order partial derivative Gaussian filters of finite spatial support to determine at least one interest point corresponding to different (s x , s y ) scale parameters, wherein an interest point identifies a location of a distinct image region in the selected image frame; and convolving a region of pixels in a surrounding neighborhood of the determined at least one interest point with the array of rectangular anisotropic second order partial derivative Gaussian filters to produce at least one interest point result that is resistant to image distortion.