Single-shot detection of 8 unique monochrome fringe patterns representing 4 distinct directions via multispectral fringe projection profilometry

AbstractSpatial resolution in three-dimensional fringe projection profilometry is determined in large part by the number and spacing of fringes projected onto an object. Due to the intensity-based nature of fringe projection profilometry, fringe patterns must be generated in succession, which is time-consuming. As a result, the surface features of highly dynamic objects are difficult to measure. Here, we introduce multispectral fringe projection profilometry, a novel method that utilizes multispectral illumination to project a multispectral fringe pattern onto an object combined with a multispectral camera to detect the deformation of the fringe patterns due to the object. The multispectral camera enables the detection of 8 unique monochrome fringe patterns representing 4 distinct directions in a single snapshot. Furthermore, for each direction, the camera detects two π-phase shifted fringe patterns. Each pair of fringe patterns can be differenced to generate a differential fringe pattern that corrects for illumination offsets and mitigates the effects of glare from highly reflective surfaces. The new multispectral method solves many practical problems related to conventional fringe projection profilometry and doubles the effective spatial resolution. The method is suitable for high-quality fast 3D profilometry at video frame rates.

Download Full-text

Three-dimensional shape measurement for thin objects based on hue-height mapping using color-encoded fringe projection

Transactions of the Institute of Measurement and Control ◽

10.1177/0142331217737597 ◽

2017 ◽

Vol 40 (14) ◽

pp. 3978-3984 ◽

Cited By ~ 1

Author(s):

Yingying Wan ◽

Yiping Cao ◽

Cheng Chen ◽

Guangkai Fu ◽

Yapin Wang

Keyword(s):

Fringe Pattern ◽

Three Dimensional ◽

Fringe Projection ◽

Shape Measurement ◽

3D Shape ◽

3D Shape Measurement ◽

Color Calibration ◽

Dimensional Shape ◽

Color Fringe ◽

Fringe Patterns

Three-dimensional (3D) shape measurement based on hue-height mapping using color-encoded fringe projection is proposed for thin objects. The projected color-encoded fringe pattern is encoded by three sinusoidal fringe patterns with 2π/3 shift phase in between into red (R), green (G) and blue (B) channels, separately. It is found that the hue component is of periodicity with the same period as the sinusoidal fringe pattern in the R channel of the color-encoded fringe and the hue distribution in a period is of monotonicity. While this color-encoded fringe pattern is projected onto an object, as long as the deformation of the captured deformed color fringe pattern is not out of a period, the 3D shape of the measured object can be reconstructed directly by hue-height mapping. This method is concise and fast with no color calibration to remove color crosstalk and no time-consuming phase extraction or phase unwrapping. The experimental results show the feasibility and the practicability of the proposed method.

Download Full-text

Investigation of Phase Pattern Modulation for Digital Fringe Projection Profilometry

Measurement Science Review ◽

10.2478/msr-2020-0006 ◽

2020 ◽

Vol 20 (1) ◽

pp. 43-49

Author(s):

Cheng-Yang Liu ◽

Chung-Yi Wang

Keyword(s):

Three Dimensional ◽

Phase Shifting ◽

Fringe Projection ◽

Depth Range ◽

Digital Fringe Projection ◽

Great Possibility ◽

Fringe Patterns ◽

Pattern Modulation ◽

Profile Reconstruction ◽

Fringe Projection Profilometry

AbstractThe fringe projection profilometry with sinusoidal patterns based on phase-shifting algorithms is commonly distorted by the nonlinear intensity response of commercial projector. In order to solve this issue, sinusoidal width modulation is presented to generate binary sinusoidal patterns for defocusing the projection. However, the residual errors in the phase maps are usually notable for highly accurate three-dimensional shape measurements. In this paper, we propose the fringe patterns of the sinusoidal, square, and triangular periodic waveforms with seven-step phase-shifting algorithm to further improve the accuracy of three-dimensional profile reconstruction. The absolute phase values are calculated by using quality guided path unwrapping. We learn that by properly selecting fringe patterns according to the target shape, the undesired harmonics of the measured surface have negligible effect on the phase values. The experiments are presented to verify the imaging performances of three fringe patterns for different testing targets. The triangular fringe patterns are suitable for the shape measurements of complex targets with curved surfaces. The results provide a great possibility for high-accuracy shape measurement technique with wider measuring depth range.

Download Full-text

Single-shot color fringe projection profilometry using two-step phase shifting and centerline marker

10.1117/12.2270797 ◽

2017 ◽

Author(s):

Shuo Xing ◽

Ping Chen ◽

Yi Xiao

Keyword(s):

Phase Shifting ◽

Fringe Projection ◽

Single Shot ◽

Color Fringe ◽

Fringe Projection Profilometry

Download Full-text

Accuracy assessment of fringe projection profilometry and digital image correlation techniques for three-dimensional shape measurements

Journal of Physics Photonics ◽

10.1088/2515-7647/abcbe4 ◽

2021 ◽

Vol 3 (1) ◽

pp. 014004

Author(s):

Hieu Nguyen ◽

Jiali Liang ◽

Yuzeng Wang ◽

Zhaoyang Wang

Keyword(s):

Digital Image Correlation ◽

Digital Image ◽

Accuracy Assessment ◽

Three Dimensional ◽

Image Correlation ◽

Fringe Projection ◽

Dimensional Shape ◽

Correlation Techniques ◽

Three Dimensional Shape ◽

Fringe Projection Profilometry

Download Full-text

Absolute phase retrieval for a single-shot fringe projection profilometry based on deep learning

Optical Engineering ◽

10.1117/1.oe.60.6.064104 ◽

2021 ◽

Vol 60 (06) ◽

Author(s):

Wenjian Li ◽

Jian Yu ◽

Shaoyan Gai ◽

Feipeng Da

Keyword(s):

Deep Learning ◽

Phase Retrieval ◽

Fringe Projection ◽

Single Shot ◽

Absolute Phase ◽

Fringe Projection Profilometry

Download Full-text

Single-shot absolute 3D shape measurement with deep-learning-based color fringe projection profilometry

Optics Letters ◽

10.1364/ol.388994 ◽

2020 ◽

Vol 45 (7) ◽

pp. 1842 ◽

Cited By ~ 15

Author(s):

Jiaming Qian ◽

Shijie Feng ◽

Yixuan Li ◽

Tianyang Tao ◽

Jing Han ◽

...

Keyword(s):

Deep Learning ◽

Fringe Projection ◽

Shape Measurement ◽

Single Shot ◽

3D Shape ◽

3D Shape Measurement ◽

Color Fringe ◽

Fringe Projection Profilometry

Download Full-text

A New Three-Dimensional Profilometer for Surface Profile Measurement Using Digital Fringe Projection and Phase Shifting

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.295-296.471 ◽

2005 ◽

Vol 295-296 ◽

pp. 471-476

Author(s):

Liang Chia Chen ◽

S.H. Tsai ◽

Kuang Chao Fan

Keyword(s):

High Speed ◽

Structured Light ◽

Three Dimensional ◽

Surface Profile ◽

Phase Shifting ◽

Fringe Projection ◽

Surface Measurement ◽

Profile Measurement ◽

Digital Fringe Projection ◽

Fringe Patterns

The development of a three-dimensional surface profilometer using digital fringe projection technology and phase-shifting principle is presented. Accurate and high-speed three-dimensional profile measurement plays a key role in determining the success of process automation and productivity. By integrating a digital micromirror device (DMD) with the developed system, exclusive advantages in projecting flexible and accurate structured-light patterns onto the object surface to be measured can be obtained. Furthermore, the developed system consists of a specially designed micro-projecting optical unit for generating flexibly optimal structured-light to accommodate requirements in terms of measurement range and resolution. Its wide angle image detection design also improves measurement resolution for detecting deformed fringe patterns. This resolves the problem in capturing effective deformed fringe patterns for phase shifting, especially when a coaxial optical layout of a stereomicroscope is employed. Experimental results verified that the maximum error was within a reasonable range of the measured depth. The developed system and the method can provide a useful and effective tool for 3D full field surface measurement ranging from µm up to cm scale.

Download Full-text

A high-performance fringe pattern generation method for fringe projection profilometry

10.1117/12.2278902 ◽

2017 ◽

Author(s):

Tao Yang ◽

Huan Huan Li ◽

Xiang Zhou ◽

Yu Qin Li ◽

Jia Yu Guo ◽

...

Keyword(s):

High Performance ◽

Fringe Pattern ◽

Pattern Generation ◽

Fringe Projection ◽

Fringe Projection Profilometry

Download Full-text

High-resolution Three-dimensional Surface Imaging Microscope Based on Digital Fringe Projection Technique

Measurement Science Review ◽

10.2478/msr-2020-0016 ◽

2020 ◽

Vol 20 (3) ◽

pp. 139-144

Author(s):

Cheng-Yang Liu ◽

Tzu-Ping Yen ◽

Chien-Wen Chen

Keyword(s):

High Resolution ◽

Imaging System ◽

Three Dimensional ◽

Fringe Projection ◽

Surface Imaging ◽

Projection Technique ◽

Digital Fringe Projection ◽

Absolute Phase ◽

The Absolute ◽

Fringe Patterns

AbstractThe three-dimensional (3-D) micro-scale surface imaging system based on the digital fringe projection technique for the assessments of microfiber and metric screw is presented in this paper. The proposed system comprises a digital light processing (DLP) projector, a set of optical lenses, a microscope, and a charge coupled device (CCD). The digital seven-step fringe patterns from the DLP projector pass through a set of optical lenses before being focused on the target surface. A set of optical lenses is designed for adjustment and size coupling of fringe patterns. A high-resolution CCD camera is employed to picture these distorted fringe patterns. The wrapped phase map is calculated by seven-step phase-shifting calculation from these distorted fringe patterns. The unwrapping calculation with quality guided path is introduced to compute the absolute phase values. The dimensional calibration methods are used to acquire the transformation between real 3-D shape and the absolute phase value. The capability of complex surface measurement for our system is demonstrated by using ISO standard screw M1.6. The experimental results for microfiber with 3 μm diameter indicate that the spatial and vertical resolutions can reach about 3 μm in our system. The proposed system provides a fast digital imaging system to examine the surface features with high-resolution for automatic optical inspection industry.

Download Full-text