PROCEEDINGS ARTICLE | June 21, 2006
Proc. SPIE. 6345, Seventh International Conference on Vibration Measurements by Laser Techniques: Advances and Applications
KEYWORDS: Statistical analysis, Defect detection, Speckle, Interferometry, Control systems, Image analysis, Speckle pattern, Radon transform, Velocimetry, Velocity measurements
Here we present our approach to apply the direct Radon transform for the analysis of interferometric images, in particular for the laser speckle velocymetry, and for the ESPI measurements. A technique for the precise velocity measurement is based on the precise calculation of the common movement of a laser speckle field. This approach allows realising a velocimeter suitable for use in extreme conditions. The latest results of our investigations are presented in this report. We also present the method of image analysis for the automatic set up of an Electronic Speckle Pattern Interferometry (ESPI). The idea of our method is to make a direct Radon-like transformation for each pixel (x0, y0) a 2D field of an image brightness B(x,y):, and than we calculate the rms spatial deviation by s, the maximum of which determines two values: (i) immediate maxφ(σs), and (ii) the corresponded angle φ((σs)max). So, from 2D function B(x,y) we have two functions depended from same 2D field, but gives a clear defect location. Our investigations show a perspective of our approach. The submitted results have both methodological and applied significance for the pattern analysis.
