Method for calculating derivative with respect to gray value in X-ray image pickup device, involves averaging virtual gray values from gray values, and calculating grey values by utilizing projection matrix

摘要

The method involves obtaining gray values by utilizing an X-ray flat detector (D) according to an angle around a rotational axis (A). The gray values for discrete angle positions are utilized for calculating dissipation of a virtual gray value for an intermediate position between two sets of neighboring discrete angle positions. The virtual gray value and another virtual gray value are averaged from the gray values with the neighboring discrete angle positions average weight values, respectively. The gray values are calculated by utilizing a projection matrix. An independent claim is also included for an X-ray image receiving device.