Abstract: The invention relates to a method and an installation for automatically measuring linear dimensions of manufactured objects (2) of a series comprising: the disposition of at least one focal point (Fj) of X-rays, on a same base straight line parallel to the rectilinear trajectory of displacement of the objects and of one or several image sensors (Ci); the acquisition, for each object during its displacement, of a set of one-dimensional images comprising, for a number (NK) of distinct section planes (Pk) containing the base straight line, a number (NP) of said images obtained along at least three different directions of projection (Dijk) in the section plane; for each object, and for each distinct section plane (Pk), the determination, from the images obtained, of a delineation of the object in the considered section plane (Pk).

Abstract: Collimation device for an X-ray detection system, the collimation device comprising: a collimator comprising a substantially planar support made of a material with partial or zero radiotransparency, the support being rotatably movable about an axis of rotation (?) which passes through the support and which is perpendicular to a first face of the support which acts as an X-ray plane of incidence referred to as the main plane of the support (P), the support (D) being provided on the first face with a slit which is completely transparent to X-rays and which is configured to generate an X-ray flow when the collimator is exposed to an X-ray source, the slit extending longitudinally in the main plane of the support along an axis located at a non-zero distance (d) from the axis of rotation (?), the slit extending through the entire thickness of the support.

Abstract: Collimation device for an X-ray detection system, the collimation device comprising: a collimator comprising a substantially planar support made of a material with partial or zero radiotransparency, the support being rotatably movable about an axis of rotation (?) which passes through the support and which is perpendicular to a first face of the support which acts as an X-ray plane of incidence referred to as the main plane of the support (P), the support (D) being provided on the first face with a slit which is completely transparent to X-rays and which is configured to generate an X-ray flow when the collimator is exposed to an X-ray source, the slit extending longitudinally in the main plane of the support along an axis located at a non-zero distance (d) from the axis of rotation (?), the slit extending through the entire thickness of the support.

Abstract: The invention relates to a method and an installation for automatically measuring linear dimensions of manufactured objects (2) of a series comprising: the disposition of at least one focal point (Fj) of X-rays, on a same base straight line parallel to the rectilinear trajectory of displacement of the objects and of one or several image sensors (Ci); the acquisition, for each object during its displacement, of a set of one-dimensional images comprising, for a number (NK) of distinct section planes (Pk) containing the base straight line, a number (NP) of said images obtained along at least three different directions of projection (Dijk) in the section plane; for each object, and for each distinct section plane (Pk), the determination, from the images obtained, of a delineation of the object in the considered section plane (Pk).

Abstract: Radiographic imaging system including: an x-ray transmission unit; an x-ray receiver unit; a plate made from a material opaque to x-rays and situated between the transmission unit and the receiver unit, the plate including at least four channels, each channel enabling a part of the x-rays emitted by the transmission unit to pass through the channel; and an image processing unit configured to determine the coordinates of the projected patterns and to calculate a position of the receiver unit from the coordinates of the projected patterns and from the coordinates of the channels.

Abstract: The invention relates to an X-ray imaging device including a rotary collimator having a region (22) which is opaque to X-rays, a first slot (24) and a second slot (26), which are transparent to X-rays and extend in two different directions, passing through the opaque region, the collimator making it possible to determine the position of an element provided with X-ray sensors in an imaging system (FIG. 1).

Abstract: The invention relates to an X-ray imaging system wherein images are obtained using an X-ray blocking element, the system comprising means for determining a position of the detector (40) on the basis of coordinates of projected patterns of the blocker (20, 220) in an image in order to especially be able to perform a calibration and/or correct the contribution of the scatter radiation in a radiographic image obtained by the system.

Abstract: The invention relates to an X-ray imaging device including a rotary collimator having a region (22) which is opaque to X-rays, a first slot (24) and a second slot (26), which are transparent to X-rays and extend in two different directions, passing through the opaque region, the collimator making it possible to determine the position of an element provided with X-ray sensors in an imaging system (FIG. 1).

Abstract: Radiographic imaging system including: an x-ray transmission unit; an x-ray receiver unit; a plate made from a material opaque to x-rays and situated between the transmission unit and the receiver unit, the plate including at least four channels, each channel enabling a part of the x-rays emitted by the transmission unit to pass through the channel; and an image processing unit configured to determine the coordinates of the projected patterns and to calculate a position of the receiver unit from the coordinates of the projected patterns and from the coordinates of the channels.

Abstract: The invention relates to an X-ray imaging system wherein images are obtained using an X-ray blocking element, the system comprising means for determining a position of the detector (40) on the basis of coordinates of projected patterns of the blocker (20, 220) in an image in order to especially be able to perform a calibration and/or correct the contribution of the scatter radiation in a radiographic image obtained by the system.

Abstract: The invention relates to a method for the determination of the position of a radiographic or radioscopic unit (16) with relation to a reference point (Rref) on producing a radiographic image of an object (10). The position of the unit (16) with relation to a reference point (Rref) is determined from the determination of the position of a test pattern (25), with relation to the unit (16), which is mechanically fixed to the object, by using the image of the test pattern with relation to the reference point (Rref). The invention further relates to a determining device for carrying out said method.

Abstract: The invention concerns a method and a system for three-dimensional reconstruction of an image representing the surface contours of at least an object (1), from at least a two-dimensional view of said object obtained by X-ray, which consists in: determining the position of the photographing source (7) in a reference repository; selecting a predefined model constituting a mean form of the object, and repeating the process until the contours of the model are such that the variations between the overhead projection rays of the contours of the two-dimensional image from the source and the model surface are minimal; selecting an orientation and a position for the model in the reference repository; then selecting a deformation of the model to modify its contours in three dimensions.

Abstract: The invention relates to a method for the determination of the position of a radiographic or radioscopic unit (16) with relation to a reference point (Rref) on producing a radiographic image of an object (10). The position of the unit (16) with relation to a reference point (Rref) is determined from the determination of the position of a test pattern (25), with relation to the unit (16), which is mechanically fixed to the object, by using the image of the test pattern with relation to the reference point (Rref). The invention further relates to a determining device for carrying out said method.

Abstract: A calculation for reconstructing tomographic images involves the decomposition of two-dimensional sets of projections of this image by a wavelet decomposition method, in which the set of projections is separated into thumbnail images expressing the whole and the higher frequency details of the projections, respectively. The reconstruction is carried out separately on the thumbnail images before making a combination. Certain properties of this decomposition, notably in the Fourier frequency domain, provide substantial reduction of the amount of calculations.

Abstract: A correct inversion formula of projections of tomography is proposed by supposing improved deformation of the object (E), that is, comprising translations, rotations and homotheties comparable to uniform dilations. Generalisations to other deformation situations of the object in question and other radiations are possible.

Abstract: Sets of projections of measurements through an object (1) the image of which is to be represented, undergo Fourier transforms before being broken down into blocks according to cutoff frequencies. The blocks are separately reconstructed in order to form a series of thumbnail images of the object, which are then combined in order to reconstruct the final image. The reconstruction calculations on the thumbnail images are rapid and often a large portion of the blocks will be discarded, notably those which are at high frequencies, whereby their contribution may frequently be neglected as well as the noise effects which accumulate therein. The invention is applied to medical or industrial tomography methods and is of larger interest for mobile objects, the movement of which may be estimated and compensated.

Abstract: A method for determining the center of rotation of a bone in a revolute joint, for example, a femur in the iliac bone, including the steps of displacing said bone, locating several ones of its positions, and memorizing them, imposing a constraint to the displacement of said center of rotation without for all this immobilizing it, and searching a point linked to the referential of said bone for which an optimization criterion taking into account said constraint is reached.

Abstract: Sets of projections of measurements through an object (1) the image of which is to be represented, undergo Fourier transforms before being broken down into blocks according to cutoff frequencies. The blocks are separately reconstructed in order to form a series of thumbnail images of the object, which are then combined in order to reconstruct the final image. The reconstruction calculations on the thumbnail images are rapid and often a large portion of the blocks will be discarded, notably those which are at high frequencies, whereby their contribution may frequently be neglected as well as the noise effects which accumulate therein.

Abstract: A three-dimensional energy distribution device includes a volume reacting to the energy of a predetermined radiation; a plurality of sources of the radiation illuminating the volume according to respective angles; and, placed between each source and the volume, a support that is transparent to the radiation and that includes an image corresponding to a density projection of a real or virtual object examined at the angle the respective source illuminates the volume, the projection having been subjected to an image correction process.