US 11,893,719 B2Granted

Single-shot differential phase contrast quantitative phase imaging method based on color multiplexed illumination

AssigneeNanjing University of Science and Technology

InventorsQian Chen, Yao Fan, Chao Zuo, Jiasong Sun, Xiangpeng Pan, Shijie Feng, Yuzhen Zhang, Guohua Gu, Jiaji Li, Jialin Zhang

Life of this patent

Estimating the term…

patentgrep

Loading patent…

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.

Claims6

Dependent claims

A single-shot differential phase contract (DPC) quantitative phase imaging (QPI) method based on color multiplexed illumination, comprising the steps of:

step 1, displaying color multiplexed illumination pattern irradiated samples by a computer-controlled high-contrast LCD TFT-LCD or high-density programmable LED array, while sending illumination control to generate a synchronous trigger signal to a color camera to acquire a color sample image, recorded as Ic;
step 2, separting the color sample image Ic in a single channel and performing a color leakage correction to obtain sample intensity images Ir,corr, Ig,corr, Ib,corr corresponding to red, green and blue three channels;
step 3, perfomring a fourier transform on the sample intensity images Ir,corr, Ig,corr, Ib,corr, to obtain spectral distribution of the sample intensity images, including setting azero frequency of three spectra is set to 0, to eliminate an effect of a background term, to obtain a DPC image spectral distribution of the sample intensity images, expressed as , , ;
step 4, based on weak phase approximation condition, calculating phase transfer function (PTF) including PTFr(ρ,θ), PTFg(ρ,θ), PTFb(ρ,θ), corresponding to different wavelengths according to parameters of an illumination function and an objective lens;
step 5, according to the PTF including PTFr(ρ,θ), PTFg(ρ,θ), PTFb(ρ,θ), at different wavelengths and a DPC image spectral distribution , , of the sample intensity images, using a Tikhonov criterion for an inverse convolution calculation to obtain a high-resolution spectrum of a sample phase, and performing an inverse Fourier transform on the high-resolution spectrum to obtain a quantitative phase distribution ϕ of the sample by the following equation:
ϕ
=
F
-
1
⁢
{
∑
k
[
PTF
k
*
(
ρ
,
θ
)
·
·
λ
k
λ
]
∑
k
❘
"\[LeftBracketingBar]"
PTF
k
*
(
ρ
,
θ
)
❘
"\[RightBracketingBar]"
2
+
β
}
where k denotes different wavelength channels, red, green, blue;
PTF*k(ρ,θ) denotes a conjugate distribution of PTFk(ρ,θ);
λk |λ denotes a wavelength normalization coefficient, λ denotes a normalized wavelength, β is a normalization parameter.

47 more elements

A single-shot differential phase contact (DPC) quantitative phase imaging (QPI) method based on color multiplexed illumination, comprising the steps of:

step 1, displaying color multiplexed illumination pattern irradiated samples by a computer-controlled high-contrast liquid crystal display TFT-LCD or high-density programmable LED array while sending illumination control to generate a synchronous trigger signal to a color camera to capture a color sample image, recorded as Ic;
and
using an alternating illumination strategyto rotate the illumination pattern 90° in any direction to illuminate the sample to acquire a second color sample image, denoted as Ic,⊥;
step 2, separating and correcting the two captured color sample images Ic, Ic,⊥, respectively, to obtain two images corresponding to each of red, green and blue channels of sample intensity image Ir,corr, Ig,corr, Ib,corr, Ir,⊥,corr, Ig,⊥,corr, Ib,⊥,corr;
step 3, solving the sample intensity images Ir,corr, Ig,corr, Ib,corr, Ir,⊥,corr, Ig,⊥,corr, Ib,⊥,corr of a single channel corresponding to the two acquired images for a spectrum and remvoing zero frequency of the spectrum so as to eliminate background term;
step 4, solving for phase transfer function (PTF) including PTFr(ρ,θ), PTFg(ρ,θ), PTFb(ρ,θ), PTFr,⊥(ρ,θ), PTFg,⊥(ρ,θ), PTFb,⊥(ρ,θ), corresponding to the two illumination patterns;
step 5, bringthe two illumination patterns corresponding to sample image spectrum and transfer function into a deconvolution calculation, and then the solving a quantitative phase distribution ϕ of the sample by the formula:
ϕ
=
F
-
1
⁢
{
∑
k
[
PTF
k
*
(
ρ
,
θ
)
·
·
λ
k
λ
+
PTF
k
,
⊥
*
(
ρ
,
θ
)
·
·
λ
k
λ
]
∑
k
(
❘
"\[LeftBracketingBar]"
PTF
k
*
(
ρ
,
θ
)
❘
"\[RightBracketingBar]"
2
+
❘
"\[LeftBracketingBar]"
PTF
k
,
⊥
*
(
ρ
,
θ
)
❘
"\[RightBracketingBar]"
2
)
+
β
}
.

81 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/766,088Filed 18 Aug 2020
Priority: CN 201910977145.X15 Oct 2019
Published: US 2022/0366552 A117 Nov 2022
Granted: 6 Feb 2024
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

G06T 5/50
Image enhancement or restoration: using two or more images, e.g. averaging or subtraction
G06T 5/90
Image enhancement or restoration: dynamic range modification of images or parts thereof
G02B 21/14
Condensers: affording illumination for phase-contrast observation
G02B 21/367
Control or image processing arrangements for digital or video microscopes: providing an output produced by processing a plurality of individual…