1. A method of obtaining short-range flare model parameters representing a short-range flare which degrades a contrast of an image generated by a lithography tool, comprising the steps of: projecting radiation through a mask using the lithography tool to generate the image containing short-range flare; measuring the short-range flare from the image to obtain measured short-range flare data; generating a simulated image corresponding to the image generated by the lithography tool using short-range flare model parameters to obtain simulated short-range flare data; comparing the simulated short-range flare data with the measured short range flare data; determining whether the short-range flare model parameters used in the simulation is appropriate based on the comparison result; and changing the values of the short-range flare model parameters used for generating the simulated image according to the measured short-range data and the simulated short-range flare data if the short-range flare model parameters used for the simulation is not appropriate.