A method for processing images, obtained by a diffraction detector, of a crystalline or polycrystalline material, in which the detector is used to measure: - a first diffraction image ( f) of the material when the material is in a reference state, giving first digital pixel values ( f ( x, y)) as a function of two pixel coordinates ( x, y), - at least a second diffraction image (g) of the material when the material is in a deformed state with respect to the reference state, the second image giving second digital pixel values ( g ( x,y)) as a function of the pixel coordinates (x,y), characterized in that in a calculator, previously storing in a memory a displacement field ( u x,u y), for displacing pixels of the first image to pixels of a deformed image, as a function of: - the two pixel coordinates (x,y), - predetermined coordinates ( x ∗, y ∗) of a center, corresponding to a normal projection, in an image plane of the detector, of a source point of the beam diffracted in the material, and - components F ^ 1 e F ^ 2 e F ^ 3 e F ^ 4 e F ^ 5 e F ^ 6 e F ^ 7 e F ^ 8 e of an elastic deformation gradient tensor F̂ e, during a first computing step (E6, E12), making the elastic deformation gradient tensor F̂ e to take a determined value ({ F̂ e}) of the elastic deformation gradient tensor, during a second computing step, computing the current displacement field ( u x,u y) from the current elastic deformation gradient tensor ( F̂ e) and from the pixel coordinates (x,y) of the first image ( f), during a third computing step, computing third digital pixel values of a deformed image (g̃ u ( x) = g( x + u ( x))) by correcting the second image (g) at the pixel coordinates to which the current displacement field ( u x,u y) has been added, over an iterative algorithm, making iterations of the first, second and third computing steps (E12, E7, E8) on modified determined tensor values ({ F̂ e}), until a criterion of convergence on the determined value ({ F̂ e}) of the elastic deformation gradient tensor is fulfilled, to compute the corresponding displacement field ( u x, u y). - a first diffraction image ( f) of the material when the material is in a reference state, giving first digital pixel values ( f ( x, y)) as a function of two pixel coordinates ( x, y), - at least a second diffraction image (g) of the material when the material is in a deformed state with respect to the reference state, the second image giving second digital pixel values ( g ( x,y)) as a function of the pixel coordinates (x,y), - the two pixel coordinates (x,y), - predetermined coordinates ( x ∗, y ∗) of a center, corresponding to a normal projection, in an image plane of the detector, of a source point of the beam diffracted in the material, and - components F ^ 1 e F ^ 2 e F ^ 3 e F ^ 4 e F ^ 5 e F ^ 6 e F ^ 7 e F ^ 8 e of an elastic deformation gradient tensor F̂ e, during a first computing step (E6, E12), making the elastic deformation gradient tensor F̂ e to take a determined value ({ F̂ e}) of the elastic deformation gradient tensor, during a second computing step, computing the current displacement field ( u x,u y) from the current elastic deformation gradient tensor ( F̂ e) and from the pixel coordinates (x,y) of the first image ( f), during a third computing step, computing third digital pixel values of a deformed image (g̃ u ( x) = g( x + u ( x))) by correcting the second image (g) at the pixel coordinates to which the current displacement field ( u x,u y) has been added, over an iterative algorithm, making iterations of the first, second and third computing steps (E12, E7, E8) on modified determined tensor values ({ F̂ e}), until a criterion of convergence on the determined value ({ F̂ e}) of the elastic deformation gradient tensor is fulfilled, to compute the corresponding displacement field ( u x, u y).