This paper presents a method to unwrap phase pixel by solely using geometric constraints of the structured light system without requiring additional image acquisition or another camera. Specifically, an artificial absolute map, Φmin, at given virtual depth plane z = zmin, is created from calibrated system; wrapped pixel-by-pixel unwrapped referring Φmin. Since Φmin defined in projector space, obtained this for each pixel. Experimental results demonstrate success proposed novel unwrapping method.

One of the major challenges employing a two-frequency (or two-wavelength) phase-shifting algorithm for absolute three-dimensional shape measurement is its sensitivity to noise. Therefore, three- or more-frequency algorithms are often used in lieu applications where noise severe. This paper proposes method use geometric constraints digital fringe projection system substantially reduce impact by allowing more than one period equivalent phase map temporal unwrapping. Experiments successfully...

This paper presents a method to achieve high-speed and high-accuracy 3D surface measurement using custom-designed mechanical projector two cameras. We developed computational framework that can absolute shape in sub-pixel accuracy through: 1) capturing precisely phase-shifted fringe patterns by synchronizing the cameras with projector; 2) generating rough disparity map between employing standard stereo-vision texture images encoded statistical patterns; 3) utilizing wrapped phase as...

State-of-the-art high-accuracy three-dimensional (3D) profilometry systems typically use a lens with fixed focal length, making it difficult for them to measure scenes large depth variations, especially dynamically changing ones. To address this need, Letter proposes novel, the best of our knowledge, autofocusing method high-resolution 3D digital fringe projection technique by (1) developing novel continuous geometric parameter model using electrically tunable lenses and (2) employing plane...

This paper presents our research findings on high-speed high-accuracy three-dimensional shape measurement using digital light processing (DLP) technologies. In particular, we compare two different sinusoidal fringe generation techniques the DLP projection devices: direct of computer-generated 8-bit patterns (a.k.a., method), and creation by defocusing binary method). mainly examines their performance applications under precisely controlled settings. Two systems were tested in this study: a...

This paper presents a novel uniaxial microscopic 3D profilometry method using structured light system with dual-telecentric lenses in micro-scale devices. Specifically, telecentric lens can produce an orthographic view of object and provide the exact size objects x y-direction. An electronically focus-tunable attached to projector rapidly precisely changes focal plane projected patterns, camera captures patterns from same perspective, computational framework analyzes relationship between...

Reducing the number of structured patterns for three-dimensional (3-D) reconstruction is great importance high-speed 3-D shape measurement. We present a method that reconstructs absolute using three projected binary patterns: one direct current (DC), low-frequency, and high-frequency fringe pattern. The procedures are (1) take difference between sinusoidal DC pattern; (2) apply Hilbert transform to images generate two phase maps; (3) employ geometric-constraint-based unwrapping unwrap...

In Fringe Projection Profilometry (FPP), achieving robust and accurate 3D reconstruction with a limited number of fringe patterns remains challenge in structured light imaging. Conventional methods require set images, but using only one or two complicates phase recovery unwrapping. this study, we introduce SFNet, symmetric fusion network that transforms images into an absolute phase. To enhance output reliability, Our framework predicts refined phases by incorporating information from...

Abstract The forensic science community raised the need for improved evidence recognition, collection, and visualization analytical instrumentation field laboratory use. While 3D optical techniques imaging static objects have been extensively studied, there is still a major gap between current knowledge collecting high‐quality footwear tire impression evidence. Among means imaging, digital fringe projection (DFP) reconstruct shape from phase information, achieving camera‐pixel spatial...

The state-of-art three-dimensional (3D) shape measurement with digital fringe projection (DFP) techniques assume that the influence of projector pixel is negligible. However, our research reveals when camera size much smaller than in object space (e.g., 1/5), can play a critical role on ultimate quality. This paper evaluates performance two shapes pixels: rectangular and diamond shaped. Both simulation experimental results demonstrated significantly size, it advantageous for ultrahigh...

This paper presents our research findings on high-speed 3D imaging using digital light processing (DLP) technologies. In particular, we compare two different sinusoidal fringe generation techniques the DLP projection devices: direct of 8-bit computer generated patterns (a.k.a, method), and creation by defocusing binary (a.k.a., method). mainly examines their performance high-accuracy measurement applications under precisely controlled settings. Two systems were tested in this study:...

This paper presents a method to overcome the light spectral range limitation of using digital-light-processing (DLP) projector for 3D shape measurement by developing mechanical projector. The enables much broader than that DLP allows. rapidly spinning disk with binary structures can generate desired sinusoidal patterns at frequency 10 kHz or higher single DC motor. By precisely synchronizing camera projector, phase-shifted fringe be accurately captured high-accuracy measurement. We further...

The structured light projection technique is a representative active method for 3-D reconstruction, but many researchers face challenges with the intricate projector calibration process. To address this complexity, we employs an additional camera, temporarily referred to as auxiliary eliminate need calibration. camera aids in constructing rational model equations, enabling generation of world coordinates based on absolute phase information. Once complete, can be removed, mitigating occlusion...

Abstract Optical metamaterials have revolutionized imaging capabilities by manipulating light‐matter interactions at the nanoscale beyond diffraction limit. Bilayer nanowire grating configurations exhibit significant potential as exceptional elements for high‐performance polarimetric systems. However, conventional computational approaches predicting electromagnetic responses are time‐consuming and labor‐intensive, thereby, practical implementation remains challenging through an iterative...

In phase-shifting profilometry (PSP), any motion during the acquisition of fringe patterns can introduce errors because it assumes both object and measurement system are stationary. Therefore, we propose a method to pixel-wise reduce when is in due motorized linear stage. The proposed introduces motion-induced error reduction algorithm, which leverages motor's encoder pinhole model camera projector. 3D shape possible with only three by applying geometric constraints digital projection...

Estimating camera pose is one of the main obstacles to implement Simultaneous Localization and Mapping (SLAM) technology. In this paper, we suggest a new phase-based SLAM technique for single-camera single-projector Digital Fringe Projection (DFP) System. This method incorporates second fixed global projector that projects fringe images gray codes across larger field view. Utilizing conventional algorithms, camera's position relative accurately calculated, compensating error accumulation...

This paper presents novel 3D geometry measurement method using cylindrical-shaped mechanical projector. The proposed projector is designed in a cylindrical shape with ON/OFF slots on the wall having distinct intervals to project multi-wavelength fringes patterns every direction, enabling omnidirectional measurement. Our approach can retrieve absolute phase for each pixel only one pattern generator generated fringe patterns. In addition, by adopting phase-based calibration that utilizes...

We present a novel method to estimate the surface normal of an object at high-speed with high dynamic range using event camera and rotating light source. Conventional photometric stereo methods use RGB frame cameras least three sources. As number sources increases, accuracy but that needs be captured which means speed map estimation is slower. Also, conventional are implemented in dark room avoid ambient illumination. To overcome these limitations, employs camera. The operates microseconds...

Phase-shifting profilometry has limitations in that any motion during the capture process can introduce errors. In this paper, we propose a method to reduce motion-induced errors at pixel level by leveraging velocity profile of linear stage and pinhole model camera projector when digital fringe projection system is on stage. Our approach utilizes only three patterns, applying geometric constraints system. It consists correction phase shift error correction. Experimental results demonstrate...