# Telecentric stereo 3D imaging with isotropic micrometer resolution bridges macro- and microscale in small Lepidopterans

## TL;DR

A new 3D imaging system with micrometer resolution is developed for detailed biological studies of small moths, bridging macro and micro scales.

## Contribution

The novel integration of telecentric stereo vision and structured illumination into a user-friendly system for non-invasive biological imaging.

## Key findings

- The system achieves 8.0 μm lateral and 4.46 μm axial resolution in a 11×11×6 mm measurement volume.
- It enables isotropic micrometer accuracy in 3D reconstructions of scattering biological objects like small moths.
- The method bridges macroscopic and microscopic resolution in biological imaging without requiring expert users.

## Abstract

We present a straightforward, application-driven telecentric stereo 3D-measurement system for high-precision measurements, designed for applications ranging from industrial quality control to biological research including scanning of Lepidoptera moths. Utilizing a dual-camera setup with telecentric lenses and structured illumination, our system achieves lateral resolution of 8.0 \documentclass[12pt]{minimal}
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\begin{document}$$\times 6$$\end{document} mm. We address challenges typically encountered when using standard libraries like OpenCV, e.g. in extrinsic parameter estimation using a dedicated calibration method that corrects for a potential model mismatch due to telecentricity. Our approach adapts existing methods, such as telecentric stereo vision and structured illumination, into an optimized, user-friendly system tailored for life science research, enabling detailed 3D-reconstructions of scattering objects, such as small moths, with isotropic micrometer accuracy. This work presents an application-driven approach for biological 3D-metrology by integrating existing technologies (telecentric stereo vision, structured illumination) into a specialized imaging platform suitable for non-invasive morphological studies. Unlike conventional CT or microscopic approaches, our method provides a balance of precision, scalability, and practical usability for non-expert users with the aim to study developmental changes in species under varying environmental conditions, while also methodically bridging the gap between macroscopic and microscopic resolution in biological imaging.