1. A method for estimating at least one deformation of the wave front of an observation system or of an object observed by said observation system, comprising acquiring, in the vicinity of the focal plane of the observation system, at least one diversity image in at least one diversity plane, the diversity image comprising a known diversity deformation; determining an image model in each diversity plane based on at least decomposition of the physical pupil of the observation system into a plurality of sub-pupils; decomposition on each sub-pupil of the deformation to be estimated in the form of at least one known deformation weighted by coefficients to be determined; determination of a transfer function of the observation system by autocorrelation of its pupil; linearization of each of the terms of the autocorrelation based on the deformation coefficients in the vicinity of the known diversity deformation; and the observed object and noise; and estimating the deformation(s) or the observed object from the determined image model(s) and the acquired image(s).