Three Dimensional Measurement of Metal Surface Shape by Using a Stereo Pair of Sem Photographs

This paper describes analytical and digital photogrammetric methods of a stereo pair of scanning electron microscope (SEM) photographs. Analytical method was applied to a triplet of stereo SEM photographs of an impression left by the diamond indenter of Vicker's hardness tester. The height error of the three dimensional measurement was ±5% and the precision is sufficient for surface shape analysis. Digital image processing method was applied to metal surface analysis. A pair of stereo SEM photographs were digitized and stereo matching process was executed to obtain three dimensional surface shape. INTRODUCTION Now the Scanning Electron Microscope (SEM) is widely used, because SEM has a capability to allow ultramicrostructures of specimens to be observed as three dimensional images. However three dimensional measurement using a pair of stereo SEM photographs is not so popular. This paper describes analytical and digital photogrammetric methods of a stereo pair of SEM photographs to obtain three dimensional surface shape of metal specimens without conventional photogrammetric instruments.