# A discussion about violin reduction: geometric analysis of contour lines and channel of minima

arXiv: https://arxiv.org/abs/2404.01995 · HTML: https://mlsanity.com/paper/2404.01995/

## Key facts

- Cited by 2 papers in the map (data through 14 Oct 2026).
- Builds on 1 of its 27 references that are in the map.
- First posted on arXiv 2 Apr 2024.

## Builds on (most cited first, 1 of 1)

- [Validation of a photogrammetric approach for the objective study of ancient bowed instruments](https://mlsanity.com/paper/2205.08745/) (2022)

## Built on by (most cited first, 2 of 2)

- [Identification of Violin Reduction via Contour Lines Classification](https://mlsanity.com/paper/2507.07743/) (2025)
- [From Elevation Maps To Contour Lines: SVM and Decision Trees to Detect Violin Width Reduction](https://mlsanity.com/paper/2604.02446/) (2026)

## Abstract (arXiv)

Some early violins have been reduced during their history to fit imposed morphological standards, while more recent ones have been built directly to these standards. We can observe differences between reduced and unreduced instruments, particularly in their contour lines and channel of minima. In a recent preliminary work, we computed and highlighted those two features for two instruments using triangular 3D meshes acquired by photogrammetry, whose fidelity has been assessed and validated with sub-millimetre accuracy. We propose here an extension to a corpus of 38 violins, violas and cellos, and introduce improved procedures, leading to a stronger discussion of the geometric analysis. We first recall the material we are working with. We then discuss how to derive the best reference plane for the violin alignment, which is crucial for the computation of contour lines and channel of minima. Finally, we show how to compute efficiently both characteristics and we illustrate our results with a few examples.