Simple SEM stereophotogrammetric method for three-dimensional evaluation of features on flat substrates.

A semi-automated method was developed for the measurement of the volume of a calcified tissue substrate which can be resorbed by single, isolated resorptive cells (osteoclasts). The procedure would, however, be applicable to the study of any pit in, or projection from, a flat surfaced specimen. Stereo-pair images are recorded with an SEM. 3-D co-ordinates of relevant surface features are derived using a stereo-comparator which outputs data directly to a microcomputer. Algorithms adopted have been chosen to give the best compromise between accuracy and speed of data acquisition.