Demultiplexing multiview images from a single-shot speckle pattern with scattering media (Conference Presentation)

2020 ◽  
Author(s):  
Xiangwen Zhu ◽  
Sujit Kumar Sahoo ◽  
Dong Wang ◽  
Huy Quoc Lam ◽  
Cuong H. Dang
Keyword(s):  
Speckle Pattern ◽  
Single Shot ◽  
Scattering Media ◽  
Multiview Images

scholarly journals Locating and Imaging through Scattering Medium in a Large Depth

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 90
Author(s):  
Shuo Zhu ◽  
Enlai Guo ◽  
Qianying Cui ◽  
Lianfa Bai ◽  
Jing Han ◽  
...  
Keyword(s):  
Phase Space ◽  
Signal To Noise Ratio ◽  
Speckle Pattern ◽  
Heuristic Method ◽  
Scattering Medium ◽  
Scattering Media ◽  
Signal To Noise ◽  
Practical Applications ◽  
Large Depth ◽  
Strong Scattering

Scattering medium brings great difficulties to locate and reconstruct objects especially when the objects are distributed in different positions. In this paper, a novel physics and learning-heuristic method is presented to locate and image the object through a strong scattering medium. A novel physics-informed framework, named DINet, is constructed to predict the depth and the image of the hidden object from the captured speckle pattern. With the phase-space constraint and the efficient network structure, the proposed method enables to locate the object with a depth mean error less than 0.05 mm, and image the object with an average peak signal-to-noise ratio (PSNR) above 24 dB, ranging from 350 mm to 1150 mm. The constructed DINet firstly solves the problem of quantitative locating and imaging via a single speckle pattern in a large depth. Comparing with the traditional methods, it paves the way to the practical applications requiring multi-physics through scattering media.

scholarly journals High-speed single-shot optical focusing through dynamic scattering media with full-phase wavefront shaping

2017 ◽  
Vol 111 (22) ◽  
pp. 221109 ◽  
Author(s):  
Ashton S. Hemphill ◽  
Yuecheng Shen ◽  
Yan Liu ◽  
Lihong V. Wang
Keyword(s):  
High Speed ◽  
Single Shot ◽  
Scattering Media ◽  
Wavefront Shaping ◽  
Optical Focusing ◽  
Dynamic Scattering

scholarly journals Guidelines for obtaining an absolute blood flow index with laser speckle contrast imaging

2021 ◽  
Author(s):  
Smrithi Sunil ◽  
Sharvari Zilpelwar ◽  
David A Boas ◽  
Dmitry D Postnov
Keyword(s):  
Blood Flow ◽  
Speckle Pattern ◽  
Quantitative Measure ◽  
Laser Speckle ◽  
Flow Index ◽  
Scattering Media ◽  
Contrast Imaging ◽  
Laser Speckle Contrast Imaging ◽  
Speckle Contrast ◽  
Blood Flow Index

Laser speckle contrast imaging (LSCI) is a technique broadly applied in research and clinical settings for full-field characterization of tissue perfusion. It is based on the analysis of speckle pattern contrast, which can be theoretically related to the decorrelation time - a quantitative measure of dynamics. A direct contrast to decorrelation time conversion, however, requires prior knowledge of specific parameters of the optical system and scattering media and thus is often impractical. For this reason, and because of the nature of some of the most common applications, LSCI is historically used to measure relative blood flow change. Over time, the belief that the absolute blood flow index measured with LSCI is not a reliable metric and thus should not be used has become more widespread. This belief has resulted from the use of LSCI to compare perfusion in different animal models and to obtain longitudinal blood flow index observations without proper consideration given to the stability of the measurement. Here, we aim to clarify the issues that give rise to variability in the repeatability of the quantitative blood flow index and to present guidelines on how to make robust absolute blood flow index measurements with conventional single-exposure LSCI. We also explain how to calibrate contrast to compare measurements from different systems and show examples of applications that are enabled by high repeatability.

scholarly journals Single-Shot Structured Light Sensor for 3D Dense and Dynamic Reconstruction

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1094 ◽  
Author(s):  
Feifei Gu ◽  
Zhan Song ◽  
Zilong Zhao
Keyword(s):  
Stereo Matching ◽  
Speckle Pattern ◽  
Structured Light ◽  
Optical Element ◽  
Depth Map ◽  
Point Clouds ◽  
Calibration Method ◽  
Acquisition Time ◽  
Single Shot ◽  
Dynamic Reconstruction

Structured light (SL) has a trade-off between acquisition time and spatial resolution. Temporally coded SL can produce a 3D reconstruction with high density, yet it is not applicable to dynamic reconstruction. On the contrary, spatially coded SL works with a single shot, but it can only achieve sparse reconstruction. This paper aims to achieve accurate 3D dense and dynamic reconstruction at the same time. A speckle-based SL sensor is presented, which consists of two cameras and a diffractive optical element (DOE) projector. The two cameras record images synchronously. First, a speckle pattern was elaborately designed and projected. Second, a high-accuracy calibration method was proposed to calibrate the system; meanwhile, the stereo images were accurately aligned by developing an optimized epipolar rectification algorithm. Then, an improved semi-global matching (SGM) algorithm was proposed to improve the correctness of the stereo matching, through which a high-quality depth map was achieved. Finally, dense point clouds could be recovered from the depth map. The DOE projector was designed with a size of 8 mm × 8 mm. The baseline between stereo cameras was controlled to be below 50 mm. Experimental results validated the effectiveness of the proposed algorithm. Compared with some other single-shot 3D systems, our system displayed a better performance. At close range, such as 0.4 m, our system could achieve submillimeter accuracy.

Single-Shot Colored Speckle Pattern for High Accuracy Depth Sensing

2019 ◽  
Vol 19 (17) ◽  
pp. 7591-7597 ◽  
Author(s):  
Boxun Fu ◽  
Fu Li ◽  
Tianjiao Zhang ◽  
Jingsong Jiang ◽  
Quanlu Li ◽  
...  
Keyword(s):  
Speckle Pattern ◽  
High Accuracy ◽  
Single Shot ◽  
Depth Sensing
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