Non-parametric Sub-pixel Local Point Spread Function Estimation

This work presents an algorithm for the local subpixel estimation of the Point Spread Function (PSF) that models the intrinsic camera blur. For this purpose, the Bernoulli(0.5) random noise calibration pattern introduced in a previous article [1] is used. This leads to a well-posed near-optimal accurate estimation. First the pattern position and its illumination conditions are accurately estimated. This allows for accurate geometric registration and radiometric correction. Once these procedures are performed, the local PSF can be directly computed by inverting a linear system. This system is well-posed and consequently its inversion does not require any regularization or prior model. The PSF estimates reach stringent accuracy levels with a relative error in the order of 2 to 5%. Source Code ANSI C source code to produce the same results as the demo and a vector image of the proposed calibration pattern are accessible on the article web page http://dx.doi.org/10.5201/ipol. 2012.admm-nppsf. Future software releases and updates will be posted at https://github. com/mdelbra/psf-estim.