Statistical approaches to image restoration

Our work has been based on X-ray images of suitcases typical of those which can be seen at an airport. Specifically we have been trying to locate components, such as a detonator, wires and (less successfully) plastic explosive, which would constitute a bomb. Standard thresholding techniques to extract lead solder, for example, do not use any spatial information. By using prior knowledge, a number of contextual techniques have been explored. Our first step is to use a deblurring algorithm on the image; it is convolved with a blurred point spread function and then deconvolved with a prior encouraging neighbouring pixels to be alike. The results obtained always seem to improve the visual quality of images.