Validation of a photogrammetric approach for the study of ancient bowed instruments

Some ancient violins have been reduced throughout their history. We propose an objective photogrammetric approach to differentiate between a reduced and an unreduced instrument, where a three-dimensional mesh is studied geometrically by examining 2D slices. First, we validate the accuracy of the photogrammetric mesh by the way of a comparison with reference images obtained with medical imaging. Then, we show how contour lines and channels of minima can be automatically extracted from the photogrammetric meshes, allowing to successfully highlight differences between instruments.