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1.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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公开(公告)号：US11487096B2
公开(公告)日：2022-11-01
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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公开(公告)号：US11106029B2
公开(公告)日：2021-08-31
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: An annular-irradiation high-resolution quantitative phase microimaging based on light intensity transfer equation is proposed here includes designing an annular aperture for the imaging system illumination; invoking the weak object approximation by using the parameters of annular illumination aperture and bright field microscopy to calculate a weak object optical transfer function (WOTF) on the basis of a partially coherent imaging theory; and collecting three intensity images by a camera and obtaining the quantitative phase image of object by resolving the light intensity transfer equation with a deconvolution algorithm.
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公开(公告)号：US11893719B2
公开(公告)日：2024-02-06
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
CPC classification number: G06T5/50 , G02B21/367
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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公开(公告)号：US11808564B2
公开(公告)日：2023-11-07
申请号：US17631542
申请日：2020-08-07
Applicant: Nanjing University of Science and Technology
Inventor： Chao Zuo , Wei Yin , Qian Chen , Shijie Feng , Jiasong Sun , Tianyang Tao , Yan Hu , Liang Zhang , Jiaming Qian
IPC: G01B11/25
CPC classification number: G01B11/2504 , G01B11/2513 , G01B11/2527
Abstract: A calibration method for fringe projection systems based on plane mirrors. Firstly, two mirrors are placed behind the tested object. Through the reflection of mirrors, the camera can image the measured object from the front and other two perspectives, so as to obtain 360-degree two-dimensional information of the measured object. The projector projects three sets of phase-shifting fringe patterns with frequencies of 1, 8, and 64. The camera captures the fringe image to obtain an absolute phase map with a frequency of 64 by using the phase-shifting method and the temporal phase unwrapping algorithm. By using the calibration parameters between the projector and the camera, the absolute phase map can be converted into three-dimensional information of the measured object. Then, the mirror calibration is realized by capturing a set of 3D feature point pairs, so that the 3D information from different perspectives is transformed into a unified world coordinate system. The calibration method does not need to artificially fix the feature pattern on plane mirrors, only needs to capture a set of 3D feature point pairs by the camera to directly realize the mirror calibration that it avoids the loss of measurement accuracy and realizes high-precision panoramic three-dimensional measurement.
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Patent Agency Ranking
公开(公告)号：US20220221270A1
公开(公告)日：2022-07-14
申请号：US17631542
申请日：2020-08-07
Applicant: Nanjing University of Science and Technology
Inventor： Chao Zuo , Wei Yin , Qian Chen , Shijie Feng , Jiasong Sun , Tianyang Tao , Yan Hu , Liang Zhang , Jiaming Qian
IPC: G01B11/25
Abstract: A calibration method for fringe projection systems based on plane mirrors. Firstly, two mirrors are placed behind the tested object. Through the reflection of mirrors, the camera can image the measured object from the front and other two perspectives, so as to obtain 360-degree two-dimensional information of the measured object. The projector projects three sets of phase-shifting fringe patterns with frequencies of 1, 8, and 64. The camera captures the fringe image to obtain an absolute phase map with a frequency of 64 by using the phase-shifting method and the temporal phase unwrapping algorithm. By using the calibration parameters between the projector and the camera, the absolute phase map can be converted into three-dimensional information of the measured object. Then, the mirror calibration is realized by capturing a set of 3D feature point pairs, so that the 3D information from different perspectives is transformed into a unified world coordinate system. The calibration method does not need to artificially fix the feature pattern on plane mirrors, only needs to capture a set of 3D feature point pairs by the camera to directly realize the mirror calibration that it avoids the loss of measurement accuracy and realizes high-precision panoramic three-dimensional measurement.
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公开(公告)号：US10911672B2
公开(公告)日：2021-02-02
申请号：US16496845
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: H04N13/246 , H04N5/232 , H04N13/239 , G01B11/25
Abstract: A highly efficient three-dimensional image acquisition method based on multi-mode composite encoding and epipolar constraint, respectively using a fast imaging mode or a high-precision imaging mode, wherein in the fast imaging mode, two phase maps having different frequencies are obtained by four stripe gratings, and a high-frequency absolute phase is obtained by means of the epipolar constraint and a left-right consistency check, and the three-dimensional image is obtained by means of a mapping relationship between the phase and three-dimensional coordinates; and in the high precision imaging mode, two phases having different frequencies are obtained by means of N+2 stripe gratings, a low-frequency absolute phase is obtained by the epipolar constraint, and the unwrapping of a high-frequency phase is assisted by means of the low-frequency absolute phase, so as to obtain the high-frequency absolute phase, and finally, the three-dimensional image is obtained by the mapping relationship between the phase and the three-dimensional coordinates. In this way, the imaging efficiency is ensured, and the imaging precision is improved.
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公开(公告)号：US11961244B2
公开(公告)日：2024-04-16
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 , G06T3/14 , G06T7/85 , H04N23/90 , G06T2207/10012 , G06T2207/10028
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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9.发明公开公开(公告)号：US20240020866A1
公开(公告)日：2024-01-18
申请号：US18025815
申请日：2021-08-18
Applicant: Nanjing University of Science and Technology
Inventor： Chao Zuo , Qian Chen , Shijie Feng , Jiasong Sun , Yuzhen Zhang , Guohua Gu
CPC classification number: G06T7/593 , G06T3/4007 , G06T7/194 , G06V10/44 , G06T2207/20228
Abstract: The invention discloses a three-dimensional (3D) measurement method based on end-to-end deep learning for speckle projection. First, the speckle pattern was projected by the projector and collected simultaneously by the stereo camera. The speckle images after stereo rectification are fed into the stereo matching network. A feature extraction sub-network based on shared weights processes the speckle images to obtain a series of low-resolution 3D feature tensors, The feature tensor is fed into the saliency object detection sub-network to detect foreground information in the speckle images, producing a full-resolution valid mask map. A 4D matching cost volume is generated using the feature tensor of both views based on the candidate disparity range, filtered by a series of 3D convolutional layers to achieve cost aggregation, so that the initial disparity map is obtained by disparity regression. The final disparity map is obtained by combining the mask map and the initial disparity map to achieve a single-frame, robust, and absolute 3D shape measurement. The invention achieves a single-frame, robust, and absolute 3D shape measurement by projecting a single speckle pattern.
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10.发明授权公开(公告)号：US11555992B2
公开(公告)日：2023-01-17
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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