Comparing 3D scanning methods for violin instrument surfaces
Estimating the intrinsic error of 3D point clouds acquisition techniques: A comparative study on instruments of the violin family
Computational Geometry
Summary
Measuring the shapes of old violins accurately is important for science and preservation, but there are many ways to do it digitally. This study compares ten different 3D scanning methods on violin plates, including cameras, lasers, and even iPads, to see how close their results are to the unknown true shape. Without knowing the exact shape, the researchers estimated each method's typical error by comparing all scans against each other. Their findings help choose the best scanning technique depending on how precise and detailed the measurements need to be.
What this means in practice
- •For musical instrument conservators: Select the most accurate 3D scanning method to document and study the shape of historical violin plates for restoration and preservation.
- •For cultural heritage digitization teams: Choose appropriate 3D acquisition techniques for digitizing violin family instruments to create reliable digital archives without ground truth geometry.
Authors
Philémon Beghin, Jean-Philippe Échard, Anthony Peeters, Arnaud Schenkel, Anne-Emmanuelle Ceulemans, François Glineur
Abstract
This study compares ten digital 3D acquisition techniques applied to violin family instrument plates, assessing their accuracy and relevance for scientific and cultural heritage applications. Evaluated methods include two photogrammetric workflows, medical and industrial computed tomography, terrestrial laser scanning, two structured-light configurations (blue light and infrared), and three consumer-grade iPad Pro approaches: TrueDepth scanning and LiDAR using two different applications. The methods were applied to five historical instruments from the "Musical Instruments Museum" (Brussels) and the "Musée de la Musique" (Paris). Since no geometric ground truth is available, accuracy is assessed through systematic pairwise point-to-plane comparisons of the resulting point clouds. These comparisons are jointly analysed to estimate the intrinsic error of each technique (i.e. the expected discrepancy between the model and the true but unknown geometry) without designating any technique as reference. Results are discussed with respect to intended uses, offering recommendations for techniques depending on the dedicated objectives.