1. An imaging processing method which produces an elasticity image of a body including a cavity depending on material(s) forming the body, wherein the method comprises: receiving a deformation image and a cavity image of the cavity from an ultrasonic probe, the deformation image illustrating a field of movement of points of the body depending on a pressure difference in the body; estimating a shape function of the body from the deformation image; calculating an elasticity image of the body depending on the shape function, on the pressure difference, and on the deformation image; superimposing the elasticity image on the cavity image; and displaying the superimposed elasticity image, wherein the step of calculating the elasticity image comprises resolving the following equation: E palpo revisited ⁡ ( θ ) = 3 2 ⁢  ∫ R i ⁡ ( θ ) R p ⁡ ( θ ) ⁢ h * ( r , θ ) ⁢ d ⁢ ⁢ r   ∫ R i ⁡ ( θ ) R p ⁡ ( θ ) ⁢ ɛ rr ⁡ ( r , θ ) ⁢ d ⁢ ⁢ r  ⁢ Δ ⁢ ⁢ P with: E palpo revisited (θ), a stress-deformation modulus depending on the angular position in the body, θ, an angular position in the body in a system of polar coordinates originating at a center of gravity of the cavity, r, the radial position in the body in the system of polar coordinates, ΔP, the pressure difference, R i (e) and R p (θ), inner and outer radii of a palpography field depending on the angular position in the body, h*(r,θ), the estimated shape function of the body depending on the radial and angular positions in the body, and ϵ rr (r,θ), a real radial deformation of the body depending on the radial and angular positions in the body.