Mod\`ele g\'eom\'etrique pour une Caract\'erisation morphom\'etrique d'individus dans des conditions \textit{in situ}

J\'er\^ome Bastien; Pierre Legreneur

arxiv: 1907.06588 · v1 · pith:BWQN2GANnew · submitted 2019-07-12 · ⚛️ physics.med-ph

Mod\`ele g\'eom\'etrique pour une Caract\'erisation morphom\'etrique d'individus dans des conditions textit{in situ}

J\'er\^ome Bastien , Pierre Legreneur This is my paper

Pith reviewed 2026-05-24 22:20 UTC · model grok-4.3

classification ⚛️ physics.med-ph

keywords morphometric characterizationgeometric modelcylindrical coordinatesnon-invasive measurementpolyarticulated chainimage reconstructionin situ analysisinterpolation

0 comments

The pith

A model using cylindrical coordinates reconstructs individual body segments from two orthogonal photographs to determine morphometric data non-invasively.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper develops a non-invasive technique for measuring morphometric characteristics of individuals in their natural conditions. It represents the body as a chain of rigid segments, each treated as a volume captured by two perpendicular photos that are then digitized. Assuming the segment borders follow cylindrical coordinates, interpolation reconstructs the three-dimensional shape and yields the main measurements. This matters for applications where direct contact or lab settings would interfere with the subject's posture or behavior.

Core claim

By modeling an individual as a polyarticulated chain of rigid segments and photographing each segment in two orthogonal planes, the borders can be reconstructed through interpolation under cylindrical coordinates, allowing the principal morphometric data to be determined.

What carries the argument

The cylindrical coordinate description of segment borders, which enables interpolation-based reconstruction from dual orthogonal images.

If this is right

The principal morphometric data are determined from the reconstructed borders.
The method is non-invasive and suitable for in situ conditions.
Each segment is modeled as a volume based on digitized photographs.
The approach allows reconstruction by interpolation from the two planes.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

The method could be extended to other fields requiring non-contact measurements, such as veterinary science.
Validation against direct measurements would test the cylindrical assumption's accuracy.
Dynamic analysis might be possible if applied to sequential images.

Load-bearing premise

The assumption that the border of each segment can be described under cylindric coordinates.

What would settle it

Comparing the interpolated volumes against direct physical measurements of the same segments to check for systematic discrepancies.

read the original abstract

We develop a non invasive method for determine morphometric caracteristic of individuals. We modelize a individual by a polyarticulated chain of rigid segments and each of these segments corresponds to a volume. For this, each segment is photographed under two orthogonal plans and each image is digitalized. By assuming that the border of each segment can be described under cylindric coordinates, the border is reconstructed by interpolation. Finally, the principal morphometric data are determined.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Desk Editor's Note private letter to a colleague

This paper outlines an unvalidated method for morphometric reconstruction using cylindrical interpolation from photos that doesn't demonstrate accuracy or novelty.

read the letter

The main thing to know is that this paper describes a method to get morphometric data from two orthogonal photos of body segments by assuming cylindrical borders and interpolating, but it gives no validation or results at all. They model the person as a polyarticulated chain of rigid segments, each treated as a volume. Photos are taken in two planes, digitized, and the border reconstructed via cylindrical coordinates interpolation. Then principal data are determined. This workflow is plausible on paper for non-invasive in-situ use. The polyarticulated model handles joints reasonably. The cylindrical assumption is the main soft spot. It may not capture real anatomy well, especially non-symmetric or tapered segments, and two views can't fully constrain it. The stress test concern about this holds based on the abstract. No data, no error metrics, no ground truth comparison means we can't assess if it works. No citations to prior photogrammetry work either, so novelty is unclear. This might appeal to someone needing a simple field method in sports or medicine, but without evidence it's not ready. It does not deserve serious referee time because the central claim rests on an unproven geometric assumption without any supporting measurements. Overall the thinking is clear but the lack of testing makes it hard to take seriously as a contribution.

Referee Report

1 major / 2 minor

Summary. The manuscript proposes a non-invasive geometric method for morphometric characterization of individuals in situ. The body is modeled as a polyarticulated chain of rigid segments, each treated as a volume. Segments are photographed in two orthogonal planes, images are digitized, borders are reconstructed via interpolation under a cylindrical coordinate assumption, and principal morphometric quantities are then extracted.

Significance. If the reconstruction were shown to be accurate, the method could offer a low-cost, portable alternative for in-situ body measurements in ergonomics or clinical settings. However, the manuscript supplies no data, validation results, error metrics, or comparisons to ground-truth 3D scans, so the practical significance cannot yet be assessed.

major comments (1)

[Abstract] Abstract (reconstruction paragraph): The central reconstruction step rests on the assumption that 'the border of each segment can be described under cylindric coordinates' from two orthogonal views followed by interpolation. No fitting procedure, radius parametrization, or error analysis is provided, and no evidence is given that this captures non-axisymmetric or tapered anatomy (e.g., torso). This assumption is load-bearing for all derived morphometric quantities.

minor comments (2)

[Abstract] Abstract: English contains multiple grammatical and spelling issues ('for determine', 'modelize a individual', 'under two orthogonal plans', 'digitalized', 'cylindric coordinates') that should be corrected for clarity.
[Abstract] Abstract: The workflow description is extremely terse; the manuscript would benefit from an explicit statement of the interpolation algorithm and the exact morphometric outputs computed.

Simulated Author's Rebuttal

1 responses · 1 unresolved

We thank the referee for the constructive review. We respond to the major comment below and note that the manuscript presents a methodological proposal rather than a validated measurement system.

read point-by-point responses

Referee: [Abstract] Abstract (reconstruction paragraph): The central reconstruction step rests on the assumption that 'the border of each segment can be described under cylindric coordinates' from two orthogonal views followed by interpolation. No fitting procedure, radius parametrization, or error analysis is provided, and no evidence is given that this captures non-axisymmetric or tapered anatomy (e.g., torso). This assumption is load-bearing for all derived morphometric quantities.

Authors: We agree the cylindrical assumption is central. From the two orthogonal digitized borders we extract radial distances at sampled longitudinal positions along each segment axis; these define the radius function in cylindrical coordinates centered on the segment, which is then linearly interpolated to reconstruct the surface. This is a deliberate simplification chosen for low-cost in-situ use with only two photographs. We acknowledge that the resulting circular cross-sections are an approximation and will not perfectly represent tapered or non-axisymmetric regions such as the torso. In the revised manuscript we will expand both the abstract and a new methods subsection to specify the exact interpolation algorithm, the radius parametrization (piecewise linear from the two views), and explicit limitations of the assumption. Because the paper focuses on model definition, no quantitative error analysis or 3D-scan validation is present; such empirical assessment lies outside the current scope. revision: partial

standing simulated objections not resolved

Empirical validation results, error metrics, or direct comparisons against ground-truth 3D scans, which are absent from the manuscript and would require new experimental data collection.

Circularity Check

0 steps flagged

No circularity: direct geometric reconstruction from explicit cylindrical ansatz

full rationale

The paper describes a modeling procedure that begins with an explicit assumption (segment borders described in cylindrical coordinates from two orthogonal digitized images) and proceeds to interpolation and morphometric calculation. No derivation step reduces a claimed prediction or result to a fitted parameter from the same data, a self-citation chain, or a renamed input. The central claim is the method itself, which is presented as a straightforward geometric reconstruction without self-referential elements or load-bearing uniqueness theorems. This is the most common honest non-finding for a methods paper whose assumptions are stated upfront rather than derived from the target quantities.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

The central claim depends on one key modeling assumption stated in the abstract; no free parameters, invented entities, or additional axioms are described.

axioms (1)

domain assumption The border of each segment can be described under cylindric coordinates
Explicitly invoked in the abstract to enable interpolation-based reconstruction of segment borders.

pith-pipeline@v0.9.0 · 5616 in / 1119 out tokens · 31864 ms · 2026-05-24T22:20:09.062116+00:00 · methodology

discussion (0)

Lean theorems connected to this paper

Citations machine-checked in the Pith Canon. Every link opens the source theorem in the public Lean library.

IndisputableMonolith/Cost/FunctionalEquation.lean washburn_uniqueness_aczel unclear

?

unclear
Relation between the paper passage and the cited Recognition theorem.

By assuming that the border of each segment can be described under cylindric coordinates, the border is reconstructed by interpolation.
IndisputableMonolith/Foundation/AbsoluteFloorClosure.lean reality_from_one_distinction unclear

?

unclear
Relation between the paper passage and the cited Recognition theorem.

En supposant que la frontière de chacun des membres peut être décrite en coordonnées cylindriques

What do these tags mean?

matches: The paper's claim is directly supported by a theorem in the formal canon.
supports: The theorem supports part of the paper's argument, but the paper may add assumptions or extra steps.
extends: The paper goes beyond the formal theorem; the theorem is a base layer rather than the whole result.
uses: The paper appears to rely on the theorem as machinery.
contradicts: The paper's claim conflicts with a theorem or certificate in the canon.
unclear: Pith found a possible connection, but the passage is too broad, indirect, or ambiguous to say the theorem truly supports the claim.