Correction of Non-Linearities in an Imaging System by Means of a Priori Knowledge in Radiography

摘要

The invention relates to a method for online correction of non-linearities in the imaging system during the data acquisition in industrial computer tomography (CT). The above provides a method for the provision of corrected projection data as an improved CT reconstruction, whereby measuring beams (q) are emitted from a radiation source (Q) which pass through the sample (10,11), the intensity of which is recorded by a detector (31). The following steps are provided: a first initialization, whereby a first orientation of the sample (10) is merely coarsely determined with a first rapid recording, a recording in which the position of the sample (10) is more accurately determined, in particular by feature point pairs, a movement, whereby after a successful recording of several projections, the position of the sample (10,11) is calculated for at least one further projection, a simulation, whereby a virtual CT is carried out using the results from the previous step, providing input data for an ensuing correction method for the CT reconstruction, carrying out a correction, whereby during data recording (70) by the detector, parameters are determined from the correction data and a correction is then carried out (73a,73b) and the reconstruction, whereby in the period at the end of the recording process corrected projection data (11*) as a data recording (70) are provided as an improved CT reconstruction (74,75).