Radiation absorption measuring system - reconstructs picture form absorption which takes place at points of object cross-section

摘要

The radiation can be X-rays which pass through the cross-sction of the object along different paths, and is scanned in order to derive absorption data. Absorption data are derived over a given range of spatial frequencies in order to reconstruct the picture by an effective convolution in a discrete way, using a convolving series of terms. A term in this series has a value of a continuously varying convolution function, integrated over the spacing between terms; the convolution function is determined by Fourier transform of the spatial frequency value multiplied by the spatial characteristic of processing; the Fourier transform is evaluated between limits of the order of a half of the effective spatial scanning frequency.