Optical measurement and interference techniques

Latest papers

• Automatic Reproducible Camera Intrinsic Calibration

  Xiangcheng Hu · 10 September 2026

  Accurate camera intrinsic calibration is fundamental to robot perception, and the accuracy depends on the quality of the collected images. However, existing target-based calibration methods often require the practitioner to manually filter out high-quality images and to specify an appropriate radial…

• Accurate Reconstruction of Gas Turbine Blade Geometry Using 3D/2D Rigid Registration and CT View Optimization

  Hristo Valtchanov, Nicolas Pich\'e, Vladimir Brailovski, Justin Byers, Catherine D\'esrosiers, Fran\c{c}ois Guibault · 2 September 2026

  Non-destructive X-ray and computed tomography (CT) testing are essential for ensuring the dimensional accuracy of manufactured components with complex internal structures, such as the cooling channels in gas turbine blades, which directly affect thermal performance and service life. This study prese…

• Sensor-Informed Per-Point Covariance for Structured-Light 3D Imaging

  Sehoon Tak, Jae-Sang Hyun · 12 August 2026

  Per-point uncertainty models are important in structured-light 3D reconstruction for probabilistic registration, fusion, and quality assessment. In practice, however, point-cloud covariances are often modeled as isotropic constants or inferred from local surface geometry and therefore do not explici…

• CableDex: Cable Length Estimation on Industrial Reels Using a Handheld Device

  Francisco Guillén, Ricardo Almeida, Bruno Silva, João C. Neves · 11 August 2026

  CableDex is a computer vision system that addresses the time-consuming and inaccurate manual measurement of cable length on industrial reels from a single photograph captured with a mobile phone. The system combines camera calibration, instance segmentation, pose estimation, and volumetric calculati…

• Beyond Reprojection Error: Camera Calibration with 3D Targets

  Dennis Ruppel, Hasan Kutlu, Kai A. Neumann, Martin Knuth, Pedro Santos, Andreas Weinmann, Arjan Kuijper · 6 August 2026

  In 3D reconstruction, camera calibration is an essential element for achieving high fidelity and accuracy of the reconstructed geometry. While existing approaches rely upon 2D planar calibration, this work proposes a framework tailored for 3D reconstruction that is based on predicting scene rays, wh…

• Rolling Shutter Camera Self-Calibration

  Yongcong Zhang, Navid Rabbani, Bangyan Liao, Chengbo Wang, Yizhen Lao, Adrien Bartoli · 4 August 2026

  Rolling shutter (RS) cameras are widely used in consumer devices, but their row-wise exposure causes distortions under motion, making geometric 3D vision problems dependent on both camera intrinsics and readout time ratio. Existing RS calibration methods rely on calibration targets or specialised ha…

• pyALDIC: A Python Implementation of Augmented Lagrangian Digital Image Correlation with a GUI, Adaptive Meshing, and Mask-Aware Subset Splitting

  Zixiang Tong, Jin Yang · 27 July 2026

  pyALDIC is an open-source Python implementation of augmented Lagrangian digital image correlation (AL-DIC) for full-field displacement and strain measurement. The software combines a graphical user interface with a scriptable Python API and supports adaptive quadtree meshing, mask-aware subset split…

• Ray-based phase error correction for miniaturized DOE projector-based FPP under single-directional hyperbolic projection

  Seung-Jae Son, Yatong An, Jae-Sang Hyun · 17 July 2026

  Fringe Projection Profilometry (FPP) systems using miniaturized DOE pro-jectors often suffer from severe phase artifacts due to nonlinear projection characteristics and limited pattern controllability. We propose a ray-based phase error correction framework that models phase artifacts along projecti…

• Repairing Shape-Prior Shortcuts in Long-Range Single-Shot Fringe Projection Profilometry

  Adam Haroon, Cody Fleming, Beiwen Li · 15 July 2026

  Single-shot fringe projection profilometry (FPP) networks that regress depth directly can exploit a shape-prior shortcut, recovering depth from object boundaries rather than from fringe phase. On a photorealistic synthetic benchmark (15,600 fringe images, 50 objects at 1.5-2.1 m standoff), the best …

• RCL-Mamba: A Dual-domain State Space Model for Measurement-oriented Image Restoration in Rotational Sparse-View Scanning Computed Laminography

  Xuyang Duan, Genyuan Zhang, Zhenjiang Dong, Chuandong Tan, Zihao Wang, Junyao Wang, Fenglin Liu · 1 July 2026

  Rotational Scanning Computed Laminography (RCL) is widely utilized for the Non-Destructive Testing(NDT) of large planar components. However, to facilitate rapid inspection, continuous sparse-view scanning is often employed, where the angular integration effect during exposure induces rotational blur…

• Wavelet-Optimized Pseudo-3D Accelerated Diffusion Model for Truncated Computed Laminography

  Genyuan Zhang, Junyao Wang, Chuandong Tan, Fenglin Liu, Yongning Zhou · 1 July 2026

  Computed Laminography (CL) is a key technology for the nondestructive testing of large plate-shaped objects. However, field-of-view (FOV) limitations inevitably lead to truncation of projected data, an ill-posed inverse problem that causes severe reconstruction artifacts. Existing deep learning meth…

• Projection-based coupling of infrared thermography and stereocorrelation-based digital image correlation

  Jendrik-Alexander Tröger, Lutz Müller-Lohse, Stefan Hartmann · 30 June 2026

  Full-field measurement techniques such as digital image correlation and infrared thermography are prevalent in experimental solid mechanics. Digital image correlation is used to analyze surface deformation, while infrared thermography quantifies surface temperature fields. However, sophisticated pro…

• Self-Supervised Dual-Frequency Phase Decomposition for Single-Shot Composite Fringe Projection Profilometry

  Jin-Hyuk Seok, Yatong An, Jae-Sang Hyun · 22 June 2026

  Single-shot fringe projection profilometry (FPP) has been actively studied for real-time measurement, dynamic object reconstruction, and motion-sensitive environments. Composite fringe patterns are advantageous in single-shot FPP because multiple frequency components can be encoded in a single patte…

• Contact-Based Fringe Projection Profilometry for High-Resolution 3-D Surface Measurement of Reflective and Transparent Objects

  Ingu Yeo, Hyung-Gun Chi, Jae-Sang Hyun · 17 June 2026

  This paper presents a contact-based 3-D surface measurement method based on a Digital Fringe Projection (DFP) system, belonging to the vision-based tactile sensing family pioneered by the commercially successful GelSight sensor. Such sensors have proven effective for robotic fingertip manipulation a…

• Diagnosing and Repairing Shape-Prior Shortcuts in Long-Range Single-Shot Fringe Projection Profilometry

  Adam Haroon, Anush Lakshman, Cody Fleming, Beiwen Li · 17 June 2026

  Learning-based single-shot fringe projection profilometry (FPP) has been studied mostly at close range. The long-range regime (standoff beyond 1 m) remains largely unaddressed: inverse-square intensity falloff lowers fringe signal-to-noise ratio and degrades physical ground truth, the single-shot pr…

• Uncertainty Quality of VGGT: An Analysis on the DTU Benchmark Dataset

  Markus Hillemann, Robert Langend\"orfer, Steven Landgraf, Markus Ulrich · 16 June 2026

  Visual Geometry Grounded Transformer (VGGT) has already attracted a great deal of attention in a short period of time, not least due to the Best Paper Award at CVPR-2025. Similar to DUSt3R and MASt3R, VGGT aims to bring about a paradigm shift by replacing established methods like bundle adjustment a…

• Comparing Commercial Depth Sensor Accuracy for Medical Applications

  Pit Henrich, Maximilian Weiherer, Franziska Hansen, Bernhard Egger, Franziska Mathis-Ullrich · 12 June 2026

  Depth estimation has numerous medical and surgical applications. We benchmark four depth sensors on a porcine bone specimen, a porcine belly specimen, and a silicone kidney phantom using stylus-sampled references. These objects contain several real-world challenges, including homogeneous surfaces, s…

• Spatially Coupled Phase-to-Depth Calibration for Fringe Projection Profilometry

  Sehoon Tak, Jae-Sang Hyun · 11 June 2026

  In fringe projection profilometry (FPP), depth is commonly recovered by fitting a phase-to-depth relation independently at each camera pixel. Although such pixel-wise calibration achieves high local accuracy, neighboring pixels can acquire markedly different calibration functions even when they obse…

• On RGB-TIR Stereo Calibration under Extreme Resolution Asymmetry

  Michał Król, Michał Salamonowicz, Władysław Skarbek, Michał Tomaszewski · 18 May 2026

  Accurate geometric calibration of RGB-thermal infrared (TIR) stereo camera systems is essential for multimodal building envelope analysis, yet remains challenging when low-cost thermal sensors with very low spatial resolution are employed. This paper presents a practical stereo calibration framework…

• Multi-frame Restoration for High-rate Lissajous Confocal Laser Endomicroscopy

  Minhee Lee, Sangyoon Lee, Jiwook Lee, Minki Hong, Kyuyoung Kim, Wonhwa Kim, Jaeho Lee · 4 May 2026

  Lissajous confocal laser endomicroscopy (CLE) is a promising solution for high speed in vivo optical biopsy for handheld scenarios. However, Lissajous scanning traces a resonant trajectory and samples only the visited pixels per frame; at high frame rates, many pixels remain unvisited, creating stru…

• 3D Reconstruction Techniques in the Manufacturing Domain: Applications, Research Opportunities and Use Cases

  Chialoon Cheng, Kaijun liu, Zhiyang Liu, Marcelo H Ang · 1 May 2026

  This comprehensive review examines the evolution and the current state of the art in three-dimensional (3D) reconstruction techniques in manufacturing applications. The analysis covers both traditional approaches and emerging deep learning methods, showing a critical research gap in unified 3d recon…

• Equivariance via Minimal Frame Averaging for More Symmetries and Efficiency

  Yuchao Lin, Jacob Helwig, Shurui Gui, Shuiwang Ji · 25 March 2026

  We consider achieving equivariance in machine learning systems via frame averaging. Current frame averaging methods involve a costly sum over large frames or rely on sampling-based approaches that only yield approximate equivariance. Here, we propose Minimal Frame Averaging (MFA), a mathematical fra…

• High-Precision 6DOF Pose Estimation via Global Phase Retrieval in Fringe Projection Profilometry for 3D Mapping

  Sehoon Tak, Keunhee Cho, Sangpil Kim, Jae-Sang Hyun · 13 March 2026

  Digital fringe projection (DFP) enables micrometer-level 3D reconstruction, yet extending it to large-scale mapping remains challenging because six-degree-of-freedom pose estimation often cannot match the reconstruction's precision. Conventional iterative closest point (ICP) registration becomes ine…

• Cylindrical Mechanical Projector for Omnidirectional Fringe Projection Profilometry

  Mincheol Choi, Gaeun Kim, Jae-Sang Hyun · 12 March 2026

  The demand for 360-degree 3D reconstruction has significantly increased in recent years across various domains such as the metaverse and 3D telecommunication. Accordingly, the importance of precise and wide-area 3D sensing technology has become emphasized. While the digital fringe projection method …

• LCAMV: High-Accuracy 3D Reconstruction of Color-Varying Objects Using LCA Correction and Minimum-Variance Fusion in Structured Light

  Wonbeen Oh, Jae-Sang Hyun · 12 March 2026

  Accurate 3D reconstruction of colored objects with structured light (SL) is hindered by lateral chromatic aberration (LCA) in optical components and uneven noise characteristics across RGB channels. This paper introduces lateral chromatic aberration correction and minimum-variance fusion (LCAMV), a …