Abstract: The invention relates to a method of estimating at least one deformation of the wave front of an observation system or of an object observed by said observation system, characterized in that: at least one diversity image is acquired, in the vicinity of the focal plane of the observation system, in at least one diversity plane, the diversity image comprising a known diversity deformation; and in that in each diversity plane, an image model is determined based on at least one decomposition of the physical pupil of the system into a plurality of subpupils; a decomposition over each subpupil of the sought-after deformation in the form of at least one known deformation weighted by coefficients to be determined; a determination of the transfer function of the system by autocorrelation of its pupil; the linearization of each of the terms of the autocorrelation as a function of the coefficients of the sought-after deformation, the linearization being performed in the vicinity of the known diversity deformation; the o