Estimating the intrinsic error of 3D point clouds acquisition techniques: A comparative study on instruments of the violin family
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.