A software method of optimising a radiograph digitising system

Abstract

There are several processes by which digitised radiographs may be obtained. One arrangement has a transilluminated film radiograph, viewed by a television camera, whose output is digitised by a frame grabber, stored in a microcomputer and presented as a digital image on a graphics display system. The system used in the present study generates images with 512*512 pixels, each containing up to 256 quantised grey scales. For large area radiography, these images are undersampled, but the system is adequate for examining small areas, and not only serves to illustrate the software method, which is more generally applicable, but also is quite adequate for the purpose of optimising a standard non-digital system.