A method for estimating the image depth map of a scene, includes the following steps: providing (E1) an image, the focus of which depends on the depth and wavelength of the considered object points of the scene, using a longitudinal chromatic optical system; determining (E2) a set of spectral images from the image provided by the longitudinal chromatic optical system; deconvoluting (E3) the spectral images to provide estimated spectral images with field depth extension; and analyzing (E4) a cost criterion depending on the estimated spectral images with field depth extension to provide an estimated depth map.