Open AccessA microcomputer‐based system for rapid on‐line stereological analysis in the SEM
Author(s) -
Howell P. G. T.,
Reid S. A.
Publication year - 1986
Publication title -
scanning
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.359
H-Index - 47
eISSN - 1932-8745
pISSN - 0161-0457
DOI - 10.1002/sca.4950080306
Subject(s) - plotter , microcomputer , pixel , raster graphics , volume (thermodynamics) , computer science , grey level , computer graphics (images) , sample (material) , stereology , digital image , automation , image processing , artificial intelligence , computer vision , computer hardware , physics , image (mathematics) , engineering , medicine , mechanical engineering , telecommunications , chip , quantum mechanics , thermodynamics
A microcomputer‐based image analysis system for the SEM is described. Through two digital‐to‐analog convertors it controls the position of the electron beam on the specimen inside the microscope. A raster of 128 × 128 pixels is created. At each pixel the signal from the BSE detector is sampled an operator‐defined number of times and the median values of the resulting data streams are stored temporarily in the memory of the computer. Stored images may be redisplayed on the visual and record CRTs of the SEM or saved onto a diskette for subsequent recall and analysis. The 256 grey level image is reduced to one having only 64 grey levels and the distribution of the number of counts falling into any of these bins is displayed on the computer monitor, or output to a plotter or printer. The number of counts in each bin represents stereologically the area (and hence volume) fraction of the sample with that grey level. Three levels of threshold may be applied to give four slices in the image. Area (and hence volume) fractions are then calculated, as is the intercept value between slices. This data is output to a printer. An abbreviated program has also been written to permit greater automation of the analysis of samples of bone. Included is a further reduction in the number of grey levels to 16, and the provision of control for an automatic stage. Although presently being applied to the study of samples of mineralised biological tissues this system could be used for any investigation requiring rapid and simple stereological analysis of specimens in the SEM.