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 body ( 9 ) to be examined is irradiated or illuminated by means of a source emitting a beam of X-rays or light rays in a propagation direction, an intensity that is attenuated according to the passage of the X-rays or light rays through the body to be examined is detected by means of a detector irradiated or illuminated by the beam, the detected intensities are converted 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, the mobile mounted support is turned by an angle of rotation about an axis of rotation with respect to the source and to the detector mounted on a stand, or the source and the detector mounted on a mobile stand are turned by an angle of rotation about an axis of rotation with respect to the support, and the following stages are carried out with the aid of a suitably programmed 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 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 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 terms of a column generating vector and a line generating vector, (2) construction of 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 (i) of the column generating vector, divided by the number (m) of terms of the line generating vector, and of the homologous term (j) of the line generating vector, divided by the number (n) of terms of the column generating vector, (3) adjustment of the coefficient of attenuation in each elementary zone by a method of least squares taking account of line boundary values defined by the sum of the (Bij) terms along a line of the initial matrix and column boundary values defined by the sum of the (Bij) terms along a column of the initial matrix, as well as of the terms of the generating vectors regarded as line or column constraints and by using the following formula: Cij = Bij + ( 1 n ) * ( ρ ⁢ ⁢ j - ∑ 1 n ⁢ ⁢ Bij ) + ( 1 m ) * ( ci - ∑ j = 1 m ⁢ ⁢ Bij ) - ( 1 nm ) * ( ∑ j = 1 m ⁢ ⁢ ρ ⁢ ⁢ j - ∑ ⁢ ijBij ) where, in this formula, Cij is the sought value Bij is the initially estimated value (n) is the number of lines of the initial matrix (m) is the number of columns of the initial matrix ∑ i = 1 n ⁢ ⁢ Cij = ρ ⁢ ⁢ j for all the values of i, the constraint of the column j ∑ j = 1 m ⁢ ⁢ Cij = ci for all the values of j, the constraint of the line i, to arrive at a properly 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, (4) repetition of the stages (1) to (3) for data acquired with different pairs of angles of rotation, and (5) treatment of the properly adjusted matrices obtained for the different pairs of angles, by a rotation operator so as to superimpose all of them on a same pair of angles (0°-90°), followed by term-by-term averaging of the properly adjusted and superimposed matrices in order to arrive at a synthesis matrix representing an image of the coefficients of attenuation of the body examined under a definition determined by the grid.