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公开(公告)号：US20210102801A1
公开(公告)日：2021-04-08
申请号：US16496815
申请日：2018-02-26
Applicant: NANJING UNIVERSITY OF SCIENCE AND TECHNOLOGY
Inventor： Qian CHEN , Chao ZUO , Shijie FENG , Jiasong SUN , Yuzhen ZHANG , Guohua GU
IPC: G01B11/25
Abstract: A super-rapid three-dimensional measurement method and system based on an improved Fourier transform contour technique is disclosed. The method comprises: firstly calibrating a measurement system to obtain calibration parameters, then cyclically projecting 2n patterns into a measured scene using a projector, wherein n patterns are binary sinusoidal fringes with different high frequency, and the other n patterns are all-white images with the values of 1, and projecting the all-white images between every two binary high-frequency sinusoidal fringes, and synchronously acquiring images using a camera; and then performing phase unwrapping on wrapped phases to obtain initial absolute phases, and correcting the initial absolute phases, and finally reconstructing a three-dimensional topography of the measured scene by exploiting the corrected absolute phases and the calibration parameters to obtain 3D spatial coordinates of the measured scene in a world coordinate system, thereby accomplishing three-dimensional topography measurement of an object. In this way, the precision of three-dimensional topography measurement is ensured, and the speed of three-dimensional topography measurement is improved.
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公开(公告)号：US20210112187A1
公开(公告)日：2021-04-15
申请号：US16496676
申请日：2018-02-26
Applicant: NANJING UNIVERSITY OF SCIENCE AND TECHNOLOGY
Inventor： Qian CHEN , Chao ZUO , Jiasong SUN , Shijie FENG , Yuzhen ZHANG , Guohua GU
Abstract: A high-illumination numerical aperture-based large field-of-view high-resolution microimaging device, and a method for iterative reconstruction, the device comprising an LED array (1), a stage (2), a condenser (3), a microscopic objective (5), a tube lens (6), and a camera (7), the LED array (1) being arranged on the forward focal plane of the condenser (3). Light emitted by the i-th lit LED unit (8) of the LED array (1) passes through the condenser (3) and converges to become parallel light illuminating a specimen (4) to be examined, which is placed on the stage (2); part of the diffracted light passing through the specimen (4) is collected by the microscopic objective (5), converged by the tube lens (6), and reaches the imaging plane of the camera (7), forming an intensity image recorded by the camera (1). The present device and method ensure controllable programming of the illumination direction, while also ensuring an illumination-numerical-aperture up to 1.20 and thus achieving a reconstruction resolution up to 0.15 μm.
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公开(公告)号：US20210103135A1
公开(公告)日：2021-04-08
申请号：US16496548
申请日：2018-02-26
Applicant: NANJING UNIVERSITY OF SCIENCE AND TECHNOLOGY
Inventor： Qian CHEN , Chao ZUO , Jiasong SUN , Shijie FENG , Yuzhen ZHANG , Guohua GU
Abstract: Annular-irradiation high-resolution quantitative phase microimaging based on light intensity transfer equation is proposed here. First, an annular aperture is designed for the imaging system illumination. And then, by invoking the weak object approximation, the parameters of annular illumination aperture and bright field microscopy are used to calculate a weak object optical transfer function (WOTF) on the basis of a partially coherent imaging theory. Finally, three intensity images are collected by a camera and the quantitative phase image of object is obtained by resolving the light intensity transfer equation with a deconvolution algorithm.
The present method effectively resolves the tradeoff between the cloudy low-frequency noise and high-frequency fuzziness in the light intensity transfer equation, and the spatial imaging resolution of phase reconstruction is greatly increased. The achievable resolution is up to twice the objective lens numerical aperture resolution of bright field microscope with more robust of low-frequency noise. There is no need to have a complicated modification of traditional bright field microscopy, and the annular aperture enables the capability of high-resolution quantitative phase imaging with a bright field microscope.-
4.发明公开公开(公告)号：US20240037765A1
公开(公告)日：2024-02-01
申请号：US17769230
申请日：2020-08-27
Applicant: NANJING UNIVERSITY OF SCIENCE AND TECHNOLOGY
Inventor： Chao ZUO , Jiaming QIAN , Qian CHEN , Shijie FENG , Tianyang TAO , Yan HU , Wei YIN , Liang ZHANG , Kai LIU , Shuaijie WU , Mingzhu XU , Jiaye WANG
CPC classification number: G06T7/337 , H04N23/90 , G06T7/85 , G06T3/0068 , G06T2207/10028 , G06T2207/10012
Abstract: Disclosed is a high-precision dynamic real-time 360-degree omnidirectional point cloud acquisition method based on fringe projection. The method comprises: firstly, by means of the fringe projection technology based on a stereoscopic phase unwrapping method, and with the assistance of an adaptive dynamic depth constraint mechanism, acquiring high-precision three-dimensional (3D) data of an object in real time without any additional auxiliary fringe pattern; and then, after a two-dimensional (2D) matching points optimized by the means of corresponding 3D information is rapidly acquired, by means of a two-thread parallel mechanism, carrying out coarse registration based on Simultaneous Localization and Mapping (SLAM) technology and fine registration based on Iterative Closest Point (ICP) technology. By means of the invention, low-cost, high-speed, high-precision, unconstrained and rapid-feedback omnidirectional 3D real-time molding becomes possible, and a new gate is opened into the fields of 360-degree workpiece 3D surface defect detection, rapid reverse forming, etc.
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Patent Agency Ranking
公开(公告)号：US20210325654A1
公开(公告)日：2021-10-21
申请号：US17294322
申请日：2019-07-05
Applicant: Nanjing University of Science and Technology
Inventor： Qian CHEN , Chao ZUO , Yao FAN , Jiasong SUN , Jiaji LI , Shijie FENG , Yuzhen ZHANG
Abstract: The patent discloses a differential phase contrast (DPC) quantitative phase microscopy method based on the optimal illumination pattern design. Firstly, the optimal illumination pattern corresponding to the isotropic phase transfer function of DPC quantitative phase imaging is derived, which is determined as a semi-annular illumination pattern with the illumination numerical aperture NAill equal to the numerical aperture NAobj of the objective lens. The illumination intensity distribution varies with the cosine of the illumination angle, and it can be expressed as S(θ)=cos(θ). This patent effectively compensates for the frequency loss of phase transfer, not only the high-frequency responses of PTF are enhanced, but also the transfer responses of low-frequency phase information is significantly improved. As a result, the optimal illumination scheme ensures the correctness and achieves high resolution phase reconstruction, while the number of illuminations is reduced to a minimum of two, which greatly increases the imaging speed, allowing for real-time dynamic, high-correctness, high-resolution phase imaging results.
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6.发明申请公开(公告)号：US20200209604A1
公开(公告)日：2020-07-02
申请号：US16633037
申请日：2018-02-26
Applicant: NANJING UNIVERSITY OF SCIENCE AND TECHNOLOGY
Inventor： Qian CHEN , Chao Zuo , Jiasong SUN , Shijie FENG , Yuzhen ZHANG , Guohua GU
Abstract: The invention discloses a programmable annular LED illumination-based high efficiency quantitative phase microscopy imaging method, the proposed method comprising the following steps: the derivation of system optical transfer function in a partially coherent illumination imaging system; the derivation of phase transfer function with the weak object approximation under the illumination of tilted axially symmetric coherent point illumination source; the extension of illumination from an axially symmetric coherence point source to a discrete annular point source, and the optical transfer function can be treated as an incoherent superposition of each pair of tilted axially symmetric coherent point sources. The acquisition of raw intensity dataset; the implementation of deconvolution for quantitative phase reconstruction. The invention derives the system phase transfer function under the tilted axially symmetric point light source in the case of partially coherent illumination, and promotes the optical phase transfer function of the discrete annular point light source. The programmability characteristic of LED array enables the annular illumination aperture to be flexibly adjustable, being applicable to different microscopic objects with different numerical apertures, and improving the compatibility and flexibility of the system.
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7.发明申请公开(公告)号：US20230122985A1
公开(公告)日：2023-04-20
申请号：US17909780
申请日：2020-08-27
Applicant: Nanjing University of Science and Technology
Inventor： Shijie FENG , Qian CHEN , Chao ZUO , Yuzhen ZHANG , Jiasong SUN , Yan HU , Wei YIN , Jiaming QIAN
IPC: G06N3/094 , G06N3/0475 , G06N3/048 , G06V10/44
Abstract: The invention discloses a single-frame fringe pattern analysis method based on multi-scale generative adversarial network. A multi-scale generative adversarial neural network model is constructed and a comprehensive loss function is applied. Next, training data are collected to train the multi-scale generative adversarial network. During the prediction, a fringe pattern is fed into the trained multi-scale network where the generator outputs the sine term, cosine term, and the modulation image of the input pattern. Finally, the arctangent function is applied to compute the phase. When the network is trained, the parameters of the network do not need to manually tune during the calculation. Since the input of the neural network is only a single fringe pattern, the invention provides an efficient and high-precision phase calculation method for moving objects.
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公开(公告)号：US20220366552A1
公开(公告)日：2022-11-17
申请号：US17766088
申请日：2020-08-18
Applicant: NANJING UNIVERSITY OF SCIENCE AND TECHNOLOGY
Inventor： Qian CHEN , Yao FAN , Chao ZUO , Jiasong SUN , Xiangpeng PAN , Shijie FENG , Yuzhen ZHANG , Guohua GU , Jiaji LI , Jialin ZHANG
Abstract: A single-shot differential phase contrast quantitative phase imaging method based on color multiplexing illumination. A color multiplexing illumination solution is used to realize single-shot differential phase contrast quantitative phase imaging. In the single-shot color multiplexing illumination solution, three illumination wavelengths of red, green, and blue are used to simultaneously illuminate a sample, and the information of the sample in multiple directions is converted into intensity information on different channels of a color image. By performing channel separation on this color image, the information about the sample at different spatial frequencies can be obtained. Such a color multiplexing illumination solution requires only one acquired image, thus enhancing the transfer response of the phase transfer function of single-shot differential phase contrast imaging in the entire frequency range, and achieving real-time dynamic quantitative phase imaging with a high contrast, a high resolution, and a high stability. In addition, an alternate illumination strategy is provided, so that a completely isotropic imaging resolution at the limit acquisition speed of the camera can be achieved.
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9.发明申请公开(公告)号：US20210356258A1
公开(公告)日：2021-11-18
申请号：US17280464
申请日：2019-07-05
Applicant: Nanjing University of Science and Technology
Inventor： Qian CHEN , Chao ZUO , Shijie FENG , Yuzhen ZHANG , Guohua GU
Abstract: The invention discloses a deep learning-based temporal phase unwrapping method for fringe projection profilometry. First, four sets of three-step phase-shifting fringe patterns with different frequencies (including 1, 8, 32, and 64) are projected to the tested objects. The three-step phase-shifting fringe images acquired by the camera are processed to obtain the wrapped phase map using a three-step phase-shifting algorithm. Then, a multi-frequency temporal phase unwrapping (MF-TPU) algorithm is used to unwrap the wrapped phase map to obtain a fringe order map of the high-frequency phase with 64 periods. A residual convolutional neural network is built, and its input data are set to be the wrapped phase maps with frequencies of 1 and 64, and the output data are set to be the fringe order map of the high-frequency phase with 64 periods. Finally, the training dataset and the validation dataset are built to train and validate the network. The network makes predictions on the test dataset to output the fringe order map of the high-frequency phase with 64 periods. The invention exploits a deep learning method to unwrap a wrapped phase map with a frequency of 64 using a wrapped phase map with a frequency of 1 and obtain an absolute phase map with fewer phase errors and higher accuracy.
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