Fringe 2009 - 6th International Workshop on Advanced Optical Metrology
du 14 au 16 septembre 2009
[en] holographic techniques ; cultural heritage ; image processing
[en] Holography and shearography techniques are in common use for precise measurements in high technology industries, such as aerospace, automotive, precision manufacturing and for the structural diagnostics of artwork. The phase map data generated by these instruments allows precise measurements of parameters such as displacement, strain and shape. The comparison of data from different measurement campaigns is useful for null testing components and for studying changes. However, the comparison of data with previous measurements is non-trivial due to the sensitivity of these techniques to alignment and to sample loading parameters. This paper addresses image and phase registration issues for holography and shearography. This manuscript describes 2D spatial co-registration to compensate for differences between the field of view between the measurements and a phase referencing to calculate the difference between the phase maps. These techniques are implemented after following a standardised measurement procedure.