Abstract: To compress the values of the pixels of a digitalized image, the values of the pixels neighboring the pixel to be processed are memorized and, according to their respective values, a code number is produced leading to the encoding process according to a composed code or to the encoding of the pixel itself, with a prefix. The successive codes are formatted and concatenated to be memorized.

Abstract: A method for reconstructing a high resolution image by interpolating intermediate values obtained from data collected over a complete revolution of the tomodensitometer. A shift of ##EQU1## is provided between the middle of the multi detector and the straight line joining the focal point of the X rays and the center of rotation and the views V.sub.i collected over a complete revolution are completed from "views" V'.sub.i resulting from a transformation:T(.theta.,.gamma.))(.theta.+(2k-1).pi.,-.gamma.),the intermediate values s.sub.i being obtained by linear interpolation from samples of the views V'.sub.i of the same ordinate .gamma., in the space [.theta.,.gamma.] and situated on each side thereof respectively.

Abstract: An image acquisition and reconstruction process for increasing the definition of the radiological image obtained by tomodensitometry. The invention consists in taking two series of data or "views" and in arranging this data by causing the views W.sub.i of the second series to undergo a translation of --.pi..theta. and a symmetry --.gamma., in the space [.theta.,.gamma.], .theta. being equal to .beta.+.gamma.; .gamma. designates the angle between the different detectors and the straightline joining the origin of the fan-shaped X ray beam to the center of rotation of the source-detectors assembly and .beta. represents the different angles of the source-detectors assembly at which acquisition of the views is made.