COMPUTER-SIMULATION OF SUPERRESOLUTION POINT-SOURCE IMAGE DETECTION

We present a computer simulation of the analysis of an ''in-focus'' two-dimensional (2-D) Airy disk. Two competing methods are used to calculate the coordinates of the center of this point spread function image. The first one is the classical technique that relies on the 2-D ''centroid'' of the image, and the second one is a more original method that uses the frequency dependence of the argument of the Fourier transform. Comparative simulations show that the latter technique [Fourier phase shift (FPS)] allows us to obtain a very good precision of better than 1% of a pixel spacing after quantization. Perturbations such as de offset reduction, quantization noise, and additive Gaussian noise are introduced in the simulation. The results show that there is an improved perturbation immunity for the FPS method.