| CPC G06T 5/50 (2013.01) [G06T 3/10 (2024.01); G06T 2207/10116 (2013.01); G06T 2207/20216 (2013.01); G06T 2207/20228 (2013.01)] | 11 Claims |
|
1. A method for correcting detector data provided by an inspection apparatus that includes a dual-energy X-ray detector, wherein the dual-energy X-ray detector includes a detector line arranged transversely to a sampling direction, the detector line including first detector elements and second detector elements which are differently responsive to an X-ray spectrum, which are arranged alternately adjacent to each other in the detector line, wherein the first and second detector elements detect X-ray radiation independently of each other and the first detector elements generate corresponding first detector data and the second detector elements generate second detector data, and wherein the inspection apparatus is arranged for transporting in the sampling direction inspection objects through the inspection apparatus for performing an imaging inspection for non-destructive inspection of the inspection objects and for providing detector data describing the inspection objects based on detection of X-rays X-raying the inspection objects with the dual-energy X-ray detector, the method comprising:
(a1) deriving missing second detector data for a location of a first detector element of the first detector elements by:
determining an interpolation value of measured second detector data from second detector elements adjacent to said first detector element;
determining a correction value based on first detector data measured with said first detector element and adjacent measured first detector data; and
correcting the interpolation value with the correction value;
and/or
(a2) deriving missing first detector data for a location of a second detector element of the second detector elements by:
determining an interpolation value of measured first detector data from first detector elements adjacent to said second detector element;
determining a correction value based on second detector data measured with said second detector element and adjacent measured second detector data; and
correcting the interpolation value with the correction value; and
wherein the method further comprises correcting an assigned brightness value determined based on determined detector data of a pixel by:
(b1) determining material values for all pixels based on actual detector data measured for each pixel and the detector data determined for each pixel, wherein the material values associated with the pixels define a material information matrix by storing a Z-effective value as a material value in the material information matrix for each pixel corresponding to a detector element;
(b2) filtering the material values determined for all pixels in the material information matrix by means of a mean-based or median-based filter operation which detects N×N material values around each pixel, where N is an integer greater than 3, preferably N=5;
(b3) determining, at each pixel where first detector data has been measured, theoretical second detector data associated with that pixel based on the material value determined for that pixel; and
(b4) determining for all pixels a respective brightness value based on the measured second detector data or the theoretical second detector data available for the respective pixel.
|