An image processing method enables an elasticity image of a body including a cavity to be produced on the basis of the material(s) forming the body, wherein the method includes the steps of: receiving a deformation image illustrating a field of movement of the points of the body on the basis of a pressure difference in the body, estimating a shape function of the body from the deformation image, calculating an elasticity image of the body on the basis of the shape function, of the pressure difference and of the deformation image.