Process for multi-scale shape measurement of displacement and / or deformation of a structural part subjected to the stresses by creating a plurality of speckle colorimetric

The invention essentially relates to a displacement measuring method and / or deformation of a study piece subjected to an external load, said method using a digital image acquisition device color and correlation means of images, characterized in that it comprises the following steps: • acquiring (250) a plurality of digital color images of the surface of the workpiece by means study of the digital image acquisition device color during the application of external stress on said workpiece study, • processing (260) the digital color image acquired at the step of acquiring a plurality of digital color images so as to bring highlight contrasting details on varying scales.