1. A method for refining search results representing possible instances of a pattern in an image having a square grid of pixels and associated positions, the search results being characterized by at least one non-translation degree of freedom (DOF), the method comprising the steps of: using a data processing device to run a program to, for each DOF instance in a DOF list, divide a corresponding DOF step size by 2, each DOF instance including the corresponding DOF step size and a 2D coordinate transform function based on a DOF associated with the DOF instance; and providing a refined search result, using the data processing device, for each search result to be refined in a result list, by performing a fine-scan procedure using the DOF list, 2D coordinate transform functions included in DOF instances in the DOF list, and the search result to be refined.