1. A method for processing a sequence of sets of 2D projection images of a moving object, the motion of which is described by a set of positions referenced by t={t 1 ,. .. , t N }, wherein the sequence of sets of 2D projection images is obtained by a medical imaging system that is in motion along a trajectory, wherein each set of 2D projection images is defined by the following equation: 
 R ( t n ) f ( t n )= p ( t n ), where t n is the position referenced, p(t n ) is a set of 2D projection images, f(t n ) is the 3D image of the object at the position referenced, and R(t n ) is a projection operator which models the sampling made by the medical imaging system according to its motion along its trajectory for the position referenced, wherein the method comprises: determining a sequence of images which minimize the function: 
 J ({right arrow over ( g )},λ)=λ S ( M{right arrow over (g)} )+ Q ({right arrow over ( g )}) where {right arrow over (g)} is a set of 3D images referenced by {right arrow over (g)}={g(t 1 ),. .. , g(t N )}, Q({right arrow over (g)}) is a term of fidelity of the sequence of images, S({right arrow over (g)}) is a function of spatial and temporal compression of the sequence of images, λ is a compressibility parameter, and M is a sequence of operators for an approximate modelling of motion referenced by M={M(t 1 ),. .. , M(t N )}, wherein the sequence of operators leads to a compression constraint augmented by partial knowledge of the motion S(M{right arrow over (g)}) where M{right arrow over (g)}={M(t 1 )g(t 1 ),. .. , M(t N )g(t N )}; wherein minimization comprises defining a decreasing sequence of degrees of compressibility for which, an estimation is determined from an initial sequence where {right arrow over (f)}={f(t 1 ),. .. , f(t N )} according to the following equations: { g -> 0 , Λ = { λ 1 , … , λ Ξ } given g -> ( λ 1 ) = A λ 1 κ [ g -> 0 ] g -> ( λ ξ ) = A λ ξ κ [ g -> ( λ ξ - 1 ) ] ∀ ξ ∈ { 2 , … , Ξ } g -> * ( Λ , g -> 0 ) = g -> ( λ Ξ ) where Λ={λ 1 ,. .. , λ E } is a decreasing sequence of degrees of compressibility {right arrow over (g)}*(Λ,{right arrow over (g)} 0 ) is the estimation, {right arrow over (g)} 0 is the initial sequence. A λ is an iteration of an algorithm enabling the minimization of J({right arrow over (g)}, λ) relative to {right arrow over (g)} for a fixed λ and A λ κ [{right arrow over (h)}] is a sequence of 3D images resulting from the application of κ iterations of algorithm A λ to a sequence of 3D images referenced by {right arrow over (h)}.