scholarly journals High-Speed Real-Time Depth Estimation by Projecting Structured Light Field

2016 ◽  
Vol 34 (1) ◽  
pp. 48-55 ◽  
Author(s):  
Takuya Matsumoto ◽  
Hiromasa Oku ◽  
Masatoshi Ishikawa
Keyword(s):  
Real Time ◽  
High Speed ◽  
Light Field ◽  
Structured Light ◽  
Depth Estimation

Structured Light Field Generated by Two Projectors for High-Speed Three Dimensional Measurement

2016 ◽  
Vol 28 (4) ◽  
pp. 523-532 ◽  
Author(s):  
Akihiro Obara ◽  
◽  
Xu Yang ◽  
Hiromasa Oku ◽  
Keyword(s):  
High Speed ◽  
Light Field ◽  
Stereo Matching ◽  
Structured Light ◽  
Three Dimensional ◽  
Depth Estimation ◽  
Image Features ◽  
Depth Information ◽  
Speed Tracking ◽  
Three Dimensional Measurement

[abstFig src='/00280004/10.jpg' width='300' text='Concept of SLF generated by two projectors' ] Triangulation is commonly used to restore 3D scenes, but its frame of less than 30 fps due to time-consuming stereo-matching is an obstacle for applications requiring that results be fed back in real time. The structured light field (SLF) our group proposed previously reduced the amount of calculation in 3D restoration, realizing high-speed measurement. Specifically, the SLF estimates depth information by projecting information on distance directly to a target. The SLF synthesized as reported, however, presents difficulty in extracting image features for depth estimation. In this paper, we propose synthesizing the SLF using two projectors with a certain layout. Our proposed SLF’s basic properties are based on an optical model. We evaluated the SLF’s performance using a prototype we developed and applied to the high-speed depth estimation of a target moving randomly at a speed of 1000 Hz. We demonstrate the target’s high-speed tracking based on high-speed depth information feedback.

Uniaxial High-Speed Micro-Scale 3D Surface Topographical Measurements Using Fringe Projection

2020 ◽  
Author(s):  
Yi Zheng ◽  
Beiwen Li
Keyword(s):  
Real Time ◽  
High Speed ◽  
Structured Light ◽  
3D Scanning ◽  
In Situ Monitoring ◽  
Physical Contact ◽  
Fringe Projection ◽  
Depth Information ◽  
Projection Technique

Abstract In-situ inspection has drawn many attentions in manufacturing due to the importance of quality assurance. With the rapid growth of additive manufacturing technology, the importance of in-line/in-situ inspections has been raised to a higher level due to many uncertainties that could occur during an additive printing process. Given this, having accurate and robust in-situ monitoring can assist corrective actions for a closed-loop control of a manufacturing process. Contact 3D profilometers such as stylus profilometers or coordinate measuring machines can achieve very high accuracies. However, due to the requirement for physical contact, such methods have limited measurement speeds and may cause damage to the tested surface. Thus, contact methods are not quite suitable for real-time in-situ metrology. Non-contact methods include both passive and active methods. Passive methods (e.g., focus variation or stereo vision) hinges on image-based depth analysis, yet the accuracies of passive methods may be impacted by light conditions of the environment and the texture quality of the surface. Active 3D scanning methods such as laser scanning or structured light are suitable for instant quality inspection due to their ability to conduct a quick non-contact 3D scan of the entire surface of a workpiece. Specifically, the fringe projection technique, as a variation of the structured light technique, has demonstrated significant potential for real-time in-situ monitoring and inspection given its merits of conducting simultaneous high-speed (from 30 Hz real-time to kilohertz high speeds) and high accuracy (tens of μm) measurements. However, high-speed 3D scanning methods like fringe projection technique are typically based on triangulation principle, meaning that the depth information is retrieved by analyzing the triangulation relationship between the light emitter (i.e., projector), the image receiver (i.e., camera) and the tested sample surface. Such measurement scheme cannot reconstruct 3D surfaces where large geometrical variations are present, such as a deep-hole or a stair geometry. This is because large geometrical variations will block the auxiliary light used in the triangulation based methods, which will resultantly cause a shadowed area to occur. In this paper, we propose a uniaxial fringe projection technique to address such limitation. We measured a stair model using both conventional triangulation based fringe projection technique and the proposed method for comparison. Our experiment demonstrates that the proposed uniaxial fringe projection technique can perform high-speed 3D scanning without shadows appearing in the scene. Quantitative testing shows that an accuracy of 35 μm can be obtained by measuring a step-height object using the proposed uniaxial fringe projection system.

scholarly journals Fast depth estimation with cost minimization for structured light field

2021 ◽  
Vol 29 (19) ◽  
pp. 30077
Author(s):  
Sen Xiang ◽  
Li Liu ◽  
Huiping Deng ◽  
Jin Wu ◽  
You Yang ◽  
...  
Keyword(s):  
Light Field ◽  
Cost Minimization ◽  
Structured Light ◽  
Depth Estimation

Real-time Depth Estimation and View Interpolation using Quasar

2016 ◽  
Vol 2016 (19) ◽  
pp. 1-6 ◽  
Author(s):  
Bart Goossens ◽  
Simon Donné ◽  
Jan Aelterman ◽  
Jonas De Vylder ◽  
Dirk Van Haerenborgh ◽  
...  
Keyword(s):  
Real Time ◽  
Depth Estimation ◽  
View Interpolation

High speed interferometric device for real-time correction of aero-optic effects

1995 ◽  
Author(s):  
Rod Clark ◽  
John Karpinsky ◽  
Gregg Borek ◽  
Eric Johnson
Keyword(s):  
Real Time ◽  
High Speed ◽  
Time Correction
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