Compressed ultrafast imaging device based on time stretching, and method and storage medium

1 . A compressed ultrafast imaging device based on time stretching, comprising:

a laser light generation module, configured to emit laser light;

a collimation module, optically connected to the laser light generation module and configured to collimate the laser light;

a laser light conversion module, optically connected to the collimation module and configured to convert the collimated laser light into spatial light;

an encoding module, optically connected to the laser light conversion module and configured to encode according to the spatial light;

an image acquisition module, connected to the encoding module; and

a control processing module, communicatively connected to the laser light generation module and the image acquisition module respectively and configured to obtain a target image sequence frame according to an observed image sent by the image acquisition module.

2 . The compressed ultrafast imaging device based on time stretching according to claim 1 , wherein the laser light generation module comprises a laser and an attenuator, and the laser is optically connected to the attenuator.

3 . The compressed ultrafast imaging device based on time stretching according to claim 1 , wherein the collimation module comprises a first reflector, a second reflector and a third reflector, and wherein the first reflector, the second reflector and the third reflector are optically connected in sequence.

4 . The compressed ultrafast imaging device based on time stretching according to claim 1 , wherein the laser light conversion module comprises a first collimator, a second collimator, and a time dispersor, and the time dispersor is optically connected to the first collimator and the second collimator respectively.

5 . The compressed ultrafast imaging device based on time stretching according to claim 1 , wherein the encoding module comprises a spatial dispersor, a fourth reflector, a fifth reflector, a sixth reflector, a first lens, a second lens, a third lens, a fourth lens, and a mask plate; and

wherein the spatial dispersor, the fourth reflector, the fifth reflector, the first lens, the second lens, the mask plate, the third lens, the fourth lens, and the sixth reflector are optically connected in sequence.

6 . A compressed ultrafast imaging method based on time stretching, applied to the control processing module of the compressed ultrafast imaging device based on time stretching according to claim 1 , comprising:

acquiring an observed image sent by the image acquisition module;

processing the observed image by using an underdetermined system of equations to obtain an original signal corresponding to the observed image; and

performing image reconstruction on the original signal according to a two-step iterative shrinkage/thresholding algorithm to obtain a target image sequence frame.

7 . The compressed ultrafast imaging method based on time stretching according to claim 6 , wherein the underdetermined system of equations is

y=Φx=Φψs=As,

where y represents a known measured value, y∈R m , Φ represents a measurement matrix, the size of Φ being M×N, x represents the original signal, x∈R n , ψ represents a sparse basis matrix, s represents a sparse coefficient, the number of non-zero elements in s being c, and c<m<n, A represents a perception matrix, A=Φψ, the size of A being M×N.

8 . The compressed ultrafast imaging method based on time stretching according to claim 7 , wherein the processing the observed image by using an underdetermined system of equations to obtain an original signal corresponding to the observed image comprises:

in response to the perceptual matrix meeting a restricted isometry property criterion, obtaining a target sparse coefficient by using a preset signal reconstruction algorithm; and

determining the original signal according to the target sparse coefficient and the underdetermined system of equations.

9 . The compressed ultrafast imaging method based on time stretching according to claim 6 , wherein the two-step iterative shrinkage/thresholding algorithm is:

I

^

=

arg

min

I

{

0.5



E

-

TSCI



2

2

+

r

⁢



x



T

⁢

V

}

,

where ∥⋅∥ 2 is a l 2 norm, ∥⋅∥Tv is a TV function, r represents a weight ratio between adjusting a regularization parameter and measuring a fidelity, I represents dynamic scene data, T represents a time-space integration operator, S represents a time shearing operator in the vertical direction, C represents an encoding operator, and E represents image data of the observed image.

10 . A non-transitory computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions are configured to cause a computer to perform the compressed ultrafast imaging method based on time stretching according to claim 6 .