1. In a search tool for finding instances of a pattern in an image, a method for specifying a generalized non-translational degree of freedom (DOF), the method comprising the steps of: receiving a function that maps a value of a DOF parameter to a two-dimensional (2D) coordinate transform value in accordance with the generalized non-translational DOF; specifying a low end of a range of values of the DOF parameter to be searched; specifying a high end of a range of values of the DOF parameter to be searched; using a data processing device to determine a step size of the DOF parameter to be searched; and using the data processing device to identify a start of a range of the DOF parameter to be searched.