Patent ID: 6975697

Claim:
Apparatus for establishing a correction characteristic curve for a reduction of artefacts in a tomography, comprising: means for providing projection data of an object consisting of a single material, wherein the projection data comprise transmission values for the object which comprise weakening values or intensity values; means for calculating a representation of the object from the projection data to obtain representation data for the object, wherein the representation data are two-dimensional or three-dimensional data, wherein means for calculating is formed to first convert the weakening values or intensity values to transmission lengths, by using a predetermined default characteristic curve to be corrected, to obtain converted transmission lengths, and to calculate the representation data from the converted transmission lengths; means for determining a measure for a transmission length of the object by using the representation data; means for determining a transmission value, which is associated to the determined measure for the transmission length; and means for generating the correction characteristic curve of several determined measures for transmission lengths and associated transmission values, wherein the correction characteristic curve comprises an association of weakening or intensity values to transmission lengths and thus represents a corrected version of the default characteristic curve.