Method for the correction of unequal conversion characteristics of image sensors

摘要

The invention relates to a method for the correction or compensation of individual differences between the conversion characteristics of the image sensors (11) and the processing units (12) of an X-ray detector which are connected thereto. It is assumed that a functional relationship in conformity with GW=Fi(Lij(phi)) exists between the quantity of radiation (phi) entering the detector and the grey value (GW) resulting therefrom for a pixel (j, i), where Lij describes the approximately linear behavior of the sensor arrangement (10) and Fi the non-linear behavior of the processing unit (12). For the inverse value Lij<-1 >a linear model function is used and for the inverse value Fi<-1 >a non-linear model function is used with parameters which can be calculated from calibration measurements with different radiation quantities (phik). During later operation of the detector these model functions can be applied to the grey values (GW) obtained in order to correct said grey values with a high precision and in real time, the storage space then required being small as a result of the use of a single non-linear inverse value for each column.