Current and future directions of on-line Transmission Electron Microscope image processing and analysis

Abstract

Image processing and analysis are increasingly employed in order to extract the maximum amount of useful information from transmission electron micrographs. Whereas most processing is carried out a posteriori, i.e. from images that have been recorded on film then digitized for computer processing, it is obviously useful to be able to improve the on-line image in near-real time for the benefit of the microscope operator. In addition, interfacing an external computer to the internal controls of modern TEMs allows on-line image analysis to provide the first step in algorithms designed to assist the operator in adjustment of microscope parameters such as alignment, astigmatism and defocus.The hardware required for on-line image processing can be as simple as a detector coupled to a TV camera, the signal from which is digitized, stored and averaged by a set of cards controlled by a host computer, with a monitor displaying the image stored in the memory card.