1. Method for the X-ray or infrared imaging of a body, in which a body to be examined is received by a support, the method comprising the steps of: a)—irradiating the body to be examined or illuminated by means of a source emitting a beam of X-rays or light rays in a propagation direction, b)—detecting an intensity that is attenuated according to the passage of the X-rays or light rays through the body to be examined means of a detector irradiated or illuminated by the beam, c)—converting the detected intensities into data enabling an attenuation of the X-rays or light rays by the body to be examined, to be determined with the aid of an analogue/digital converter, d)—turning the mobile mounted support by an angle of rotation about an axis of rotation with respect to the source and to the detector mounted on a stand, or turning the source and the detector mounted on a mobile stand by an angle of rotation about an axis of rotation with respect to the support, and e)—carrying out the following stages with the aid of a computer: (1) averaging the data obtained from the conversion of the detected intensities in a band of the detector for a first angle of rotation, to obtain n mean values (c i ) in n elementary segments of the band, and averaging the data obtained from the conversion of the detected intensities in the band of the detector for a second angle of rotation, preferably differing by 90° from the first angle of rotation, to obtain m mean values (ρ j ) in m elementary segments of the band, wherein the n and m elementary segments produce a grid of n×m elementary zones of a sectional plane of the object to be examined perpendicular to the axis of rotation and wherein the n and m mean values respectively are the (c i ) terms of a column generating vector and the (ρ j ) terms of a line generating vector, (2) building an initial matrix (n,m) with the terms of the generating vectors, by assigning to each elementary zone a line term and a column term (Bij) representing a coefficient of attenuation defined by the half sum of the homologue term (c i ) of the column generating vector, divided by the number (m) of terms of the line generating vector, and of the homologous term (ρ j ) of the line generating vector, divided by the number (n) of terms of the column generating vector, B ij = 1 2 ⁢ ( ρ j n + c i m ) (3) adjusting the coefficient of attenuation in each elementary zone using the following formula: C ij = ρ j n + c i m - 1 2 ⁢ nm ⁢ ( ∑ i = 1 n ⁢ ⁢ c i + ∑ j = 1 m ⁢ ⁢ ρ j ) where, Cij is the sought value of the coefficient of attenuation of the elementary zone (i,j) of the grid, (n) is the number of lines of the initial matrix, (m) is the number of columns of the initial matrix, ρ j is the j-th term of the line generating vector calculated at stage (1), and c i is the i-th term of the column generating vector calculated at stage (1), to arrive at an image of the sectional plane of the body examined under the first and the second angles of rotation, corresponding to an adjusted matrix, for which the line and column boundary values calculated with the adjusted values (Cij) are equal, respectively, for each line and column, to the terms of the line and column generating vectors, ∑ j = 1 m ⁢ ⁢ Cij = c i ∑ i = 1 n ⁢ Cij = ρ j (4) repeating the stages (1) to (3) for data acquired with different pairs of angles of rotation to respectively arrive at different adjusted matrices corresponding to different images of the sectional plane of the body examined under the different pairs of angles of rotation, (5) by means of a rotation operator, superimposing on a same pair of angles (0°-90°) all the properly adjusted matrices obtained for the different pairs of angles, and (6) displaying on the computer a synthesis image of the sectional plane of the examined body, corresponding to a synthesis matrix of the coefficients of attenuation obtained, for each elementary zone (i,j) of the grid, a term-by-term averaging of all the adjusted matrices obtained at stage (4) and superimposed at stage (5).