摘要:
A method of correcting detector signals, in particular for scatter noise correction with an projection-based imaging device, comprises the steps of irradiating an object (1) with a radiation beam (2) including a plurality of discrete beam component (3, 3.1, 3.2) bounded by a plurality of masked angular ranges (4, 4.1, 4.2), so that the object (1) is partially irradiated with the beam components (3, 3.1, 3.2), detecting radiation transmitted through the object (1) with a detector device (30) comprising a plurality of detector portions (32, 32.1, 32.2, 33.1, 33.2), wherein direct radiation of the beam components (3) is detected by directly irradiated detector portions (32, 32.1, 32.2), detecting indirect radiation occurring in the masked angular ranges by masked detector portions (33.1, 33.2) adjacent to the directly irradiated detector portions (32, 32.1, 32.2), and correcting detector signals of the directly irradiated detector portions (32, 32.1, 32.2) in dependence on the detector signals of the masked detector portions (33.1, 33.2) for providing corrected detector signals. Furthermore, an imaging device for projection-based imaging is described.
摘要:
An image processing method for providing a digitized image as an approximation of an image function ƒ, wherein the digitized image comprises a plurality of pixels with a predetermined pixel size, comprises the steps of providing the image function ƒ from Radon data comprising a plurality of projection functions measured corresponding to a plurality of predetermined projection directions (v), and determining pixel values from the image function, the pixel values representing the digitized image to be obtained, wherein the pixel values are determined in dependence on at least two image function values within the pixel size of the respective pixel. Furthermore, an imaging method and an imaging device using the image processing method are described.
摘要:
Imaging apparatus, for analyzing an object, comprising: a radiation source for transmission of radiation through said object in a section plane of said object; a radiation detector for detecting said radiation in said section plane of said object after transmission through said object; and a masking device for masking out a part of said radiation, wherein said masked part of said radiation is movable in said section plane relative to said radiation detector during said analysis of said object.
摘要:
An irradiation method, in particular for imaging a region of investigation (2) of an object (1), comprises generating at least one energy input beam (3) with at least one energy input beam source (210), wherein the at least one energy input beam (3) comprises a plurality of individual energy input beam components (3.1, 3.2, 3.3, . . . ), and irradiating the region of investigation (2) with the at least one energy input beam (3) along a plurality of projection directions, wherein the energy input beam components (3.1, 3.2, 3.3, . . . ) are formed with at least one beam mask (211) made of an energy input shielding material with through holes. Furthermore, imaging methods and devices for irradiating or imaging the object are described.
摘要:
An autostereoscopic display includes a background illumination with a multiplicity of parallel light strip groups with in each case at least two parallel light strips, wherein the individual light strip groups are arranged next to one another with a first grid dimension, and a lens grid arranged before the background illumination and has a multiplicity of parallel lens strips, wherein the lens strips are arranged next to one another with a second grid dimension, as well as a light modulator arranged before the lens grid and displays image information.
摘要:
A method of reconstructing a tomographic image of a region of investigation with reduced artifacts, said method comprises the steps of (a) reconstructing a first partial image and a second partial image of the region of investigation from first and second projection profiles each of which including projection data collected at first and second different groups of parallel projection lines, resp., wherein the first and second projection profiles are provided such that streak aliasing artifacts in the first and second partial images have different spatial phases, and (b) generating the tomographic image of the region of investigation by superimposing the first and second partial images. Preferably, the first and second projection profiles are constructed such that streak aliasing artifacts in the first and second partial images have opposite spatial phases relative to each other. Furthermore, an imaging method and an imaging device for imaging a region of investigation in an object are described.
摘要:
A method of reconstructing an (n+1)-dimensional image function ƒ representing a region of investigation comprises determining the image function ƒ from n-dimensional or less dimensional Radon data comprising a plurality of projection functions pθ(t) measured corresponding to a plurality of predetermined projection directions (Θ), wherein the image function ƒ is determined as a sum of polynomials multiplied with values of the projection functions pθ(t). Imaging methods, imaging devices, and computer tomography devices using this reconstruction method are described.
摘要:
A tomography apparatus that generates images of an object includes a radiation source emitting a radiation beam, wherein the radiation beam rotates around the object and penetrates the object; a radiation detector rotating around the object opposite the radiation source so that the radiation detector detects the radiation beam after penetration of the object; a radiation mask surrounding the object that masks the radiation beam, wherein the radiation mask is arranged in a path of the radiation beam between the radiation source and the radiation detector and the radiation beam passes the radiation mask only once between the radiation source and the radiation detector.
摘要:
An autostereoscopic display includes a background illumination with a multiplicity of parallel light strip groups with in each case at least two parallel light strips, wherein the individual light strip groups are arranged next to one another with a first grid dimension, and a lens grid arranged before the background illumination and has a multiplicity of parallel lens strips, wherein the lens strips are arranged next to one another with a second grid dimension, as well as a light modulator arranged before the lens grid and displays image information.
摘要:
A method of reconstructing an image function on the basis of a plurality of projection profiles corresponding to a plurality of projection directions through a region of investigation, each projection profile including a series of value positions, wherein measured projection values corresponding to projection lines parallel to the respective projection direction are assigned to respective value positions and a plurality of remaining value positions are empty, comprises the steps of (a) assigning first interpolation values to the empty value positions for constructing a plurality of interpolation profiles on the basis of the projection profiles, wherein the first interpolation values are obtained from a first interpolation within a group of measured projection values having the same value position in different projection profiles, and (b) determining the image function by applying a predetermined reconstruction algorithm on the interpolation profiles.