Close Range Photogrammetry and NDT imaging techniques for the characterization of timber structural elements

In the research presented in this paper, the combined use of close range photogrammetry, to map and measure external features, and NDT techniques, to detect internal defects of wood, is proposed for the characterization of structural timber on site. Experimental results are presented, based on the integrated use of digital photogrammetry, sonic tomography, image analysis and CAD techniques. Feature points and contour lines that reflect information about the macroscopic heterogeneities in the material, both visible and internal, have been extracted by image processing techniques, using segmentation algorithms. From image data, geometrical data of the detected features have been extracted, for further analysis (measurement of strength affecting characteristics, 3D visualization and modelling of the macroscopic material features).