PROGRAMMABLE ANNULAR LED ILLUMINATION-BASED HIGH EFFICIENCY QUANTITATIVE PHASE MICROSCOPY IMAGING METHOD

    公开(公告)号:US20200209604A1

    公开(公告)日:2020-07-02

    申请号:US16633037

    申请日:2018-02-26

    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.

    ANNULAR-IRRADIATION HIGH-RESOLUTION QUANTITATIVE PHASE MICROIMAGING METHOD BASED ON LIGHT INTENSITY TRANSFER EQUATION

    公开(公告)号:US20210103135A1

    公开(公告)日:2021-04-08

    申请号:US16496548

    申请日:2018-02-26

    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.

    A SINGLE-SHOT DIFFERENTIAL PHASE CONTRAST QUANTITATIVE PHASE IMAGING METHOD BASED ON COLOR MULTIPLEXED ILLUMINATION

    公开(公告)号:US20220366552A1

    公开(公告)日:2022-11-17

    申请号:US17766088

    申请日:2020-08-18

    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.

    A DEEP LEARNING-BASED TEMPORAL PHASE UNWRAPPING METHOD FOR FRINGE PROJECTION PROFILOMETRY

    公开(公告)号:US20210356258A1

    公开(公告)日:2021-11-18

    申请号:US17280464

    申请日:2019-07-05

    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.

    A MICROSCOPIC IMAGING METHOD OF PHASE CONTRAST AND DIFFERENTIAL INTERFERENCE CONTRAST BASED ON THE TRANSPORT OF INTENSITY EQUATION

    公开(公告)号:US20220011563A1

    公开(公告)日:2022-01-13

    申请号:US17294019

    申请日:2019-07-05

    Abstract: The invention claims a microscopic imaging method of phase contrast (PC) and differential interference contrast (DIC) based on the transport of intensity equation (TIE). Firstly, three intensity images are captured along the optical axis; secondly, TIE is solved by deconvolution to obtain the quantitative phase; then, the intensity image under the DIC imaging mode is obtained according to the DIC imaging principle; finally, the corresponding phase image of PC imaging mode is obtained according to the PC imaging principle. The proposed approach can endow the bright-field microscope with the ability to realize PC and DIC imaging without complex modification of the traditional bright-field microscope. In other words, this method only needs to use the traditional bright-field microscope without adding any complex hardware. Through the PC and DIC algorithms, this method has the advantages of quantitative, high-speed, low-cost, simple structure, and less external interference. In addition, it has the same imaging performance as the phase contrast microscope and differential interference contrast microscope, which are expensive, complex-structure, and has strict environmental conditions.

    SUPER-RAPID THREE-DIMENSIONAL TOPOGRAPHY MEASUREMENT METHOD AND SYSTEM BASED ON IMPROVED FOURIER TRANSFORM CONTOUR TECHNIQUE

    公开(公告)号:US20210102801A1

    公开(公告)日:2021-04-08

    申请号:US16496815

    申请日:2018-02-26

    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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