Abstract: The present invention generally relates to an apparatus and a method for computing an estimate position of a micro-image produced by a micro-lens of an array of micro-lenses of an optical acquisition system in order to calibrate said optical acquisition system. Existing solutions for estimating the position of the micro-image are not designed to be fast and are resource consuming. It is proposed to estimate the position of the micro-image by extracting the parameters D,?,x0,0,y0,0 defining this position from an image in the Fourier domain. The four parameters D,?,x0,0,y0,0 characterizing the position of the micro-image relatively to a pixel grid of a sensor of a plenoptic camera are estimated by knowing the accurate position of peaks of a Dirac comb in the image in the Fourier domain.

Abstract: A method for obtaining a refocused image from 4D raw light field data for a given focus plane value g is described. The method is executed by an electronic device and is remarkable in that it comprises determining at least one pixel value, for at least one color component, of the refocused image at coordinates (k, l)?N2. The at least one projected pixel value with coordinates comprised in a neighborhood of said coordinates (k, l), for the at least one color component is determined, weighted and updated.