Affiliations: Physics Department, Technical University of Denmark, DK-2800 Lyngby, Denmark | Danish Institute of Fundamental Metrology, Lundtoftevej 100, DK-2800 Lyngby, Denmark | Institute of Experimental Physics, Warsaw University, Hoza 69, 00-681 Warsaw, Poland
Note: [] Present address: Danish Space Research Institute, Gl. Lundtoftevej 7, DK-2800 Lyngby, Denmark.
Abstract: The conventional photographic prints obtained from double crystal x-ray topography are often hard to interprete and reproduce. Photographic enhancement methods require skillful work by an experienced photographer. They are time consuming and the image information is difficult to present quantitatively. Alternatively, image processing methods may be applied by digitization of the original topographic recording. Image processing computer programs may be applied, e.g., for image enhancement and for quantification of image information. This paper’s main interest is related to
—obtaining a sufficiently high magnification ratio;
—correcting for intensity variations within the image;
—applying spatial filtering techniques in order to reduce film grain noise;
—improving contrast, and
—retrieving quantative information on image details.
The application of such image processing routines is exemplified on topographs obtained by a double-crystal diffractometer set to the (+, -) asymmetric-asymmetric setting. A silicon single crystal was used as the monochromator, while the sample was a silicon single crystal which had undergone both surface damage and metallic contamination before the application of Rapid Thermal Annealing (RTA). Hence, well-defined microdefects are found within the sample. These computer-processed images are compared with corresponding images enhanced by conventional techniques. The results provide indications of which enhancement procedures should be applied for qualitative image improvement and for quantification of image details within different types of topographic recordings.
