Quantitative photogrammetric analysis and qualitative stereoscopic analysis of SEM images

Abstract

SUMMARYThis paper is concerned with methods for obtaining three‐dimensional (3D) information from scanning electron microscope (SEM) images. It may come as a surprise that this topic merits separate discussion, because, it is generally accepted that every SEM image of a rough surface using the secondary electron emission mode gives apparent 3D information. This is true to some extent, since SEM images are comparable with photographs of rough surfaces illuminated with light coming from one direction, but our main concern here will be with 3D visualization from stereoscopic pairs of images. However, there are other ways in which 3D information may be obtained, even in the SEM, and these are considered first. The remainder of the paper is largely concerned with the use of stereoscopic parallaxes, whether or not they are visualized as such. Commonly used methods for viewing stereo‐pairs are described, followed by simple methods for measuring stereoscopic parallaxes. Formulae for reducing linear measurements in the two photographs to real height differences are given.