New developments in data processing of noisy images

In some of the methods used in metallography, the signal-noise ratio is so low that direct interpretation is not possible. With regard to microanalysis, the segregation in steels is currently being studied using quantitative X-ray mapping. The acquisition time and counting statistics are limiting factors, particularly for elements in low concentration that present low count rates compared with the background level. Noise from the useful information can be filtered out by geostatistical techniques. A new commercial software, IMAGEO, has been developed by the Ecole des Mines de Paris for noise filtering and signal deconvolution. The main features of this method and the software are described with detailed application examples. With this technique, it is now possible not only to get information from images that would be unusable, but, in the case of microanalysis, to save time for elements in higher concentration by using less counting time.