In recent years quantitative high resolution electron microscopy (HREM) became a reliable tool to investigate physical processes at an atomic scale. Certainly, there is no unique approach to quantify the information content from lattice images. However, specific methods like Chemical Imaging^ and QUANTITEM were established that allow to investigate the atomic structure of crystalline solids quantitatively and almost routinely.

Nevertheless, there are limits to the application of these methods and they are of principle and of practical nature. Obviously, the resolution of quantitative HRTEM is limited by the point resolution of modern microscopes that has reached 0.1 mn. However, the quantification of the information from lattice images requires two important steps, namely, the application of a pattern recognition procedure and the extraction of changes of the electron scattering potential from the lattice images. The application of the pattern recognition procedure influences the lateral resolution of the method because a lattice image has to be broken up into unit cells of identical size (figure 1).