Light field microscope-based image acquisition method and apparatus
Light field microscope-based image acquisition apparatuses and methods are provided. The light field microscope-based image acquisition apparatus includes a lenslet synthesis processing unit configured to acquire a virtual lenslet image using a multi-lenslet image group; a sub-aperture image conversion unit configured to convert the virtual lenslet image generated in the lenslet synthesis processing unit into a sub-aperture image; and a 3D conversion unit configured to convert the sub-aperture image generated in the sub-aperture image conversion unit into a focal-stack image.
1 . A light field microscope-based image acquisition apparatus comprising:
a lenslet synthesis processor unit configured to acquire a virtual lenslet image using a multi-lenslet image group received from microlenses;
a sub-aperture image conversion processor configured to convert the virtual lenslet image generated in the lenslet synthesis processing processor into a sub-aperture image; and
a 3D conversion processor configured to convert the sub-aperture image generated in the sub-aperture image conversion processor into a focal-stack image.
2 . The light field microscope-based image acquisition apparatus of claim 1 , wherein the multi-lenslet image group is generated in such a way to acquire a plurality of image frame information through microlenses whose arrangement position is changed in each time frame within a set imaging sensor area.
3 . The light field microscope-based image acquisition apparatus of claim 2 , wherein the multi-lenslet image group is acquired by rotating, for a set time, a disk on which a plurality of microlenses are arranged.
4 . The light field microscope-based image acquisition apparatus of claim 2 , wherein the lenslet synthesis processor superimposes a plurality of image frames configuring the multi-lenslet image group to determine a disposition relationship of microlenses for each image.
5 . The light field microscope-based image acquisition apparatus of claim 4 , wherein the sub-aperture image conversion processor finds a pixel corresponding to coordinates of a microlens in the virtual lenslet image, and maps the pixel to a coordinate position of the sub-aperture image to be converted.
6 . The light field microscope-based image acquisition apparatus of claim 5 , wherein
the sub-aperture image conversion processor generates a pixel value of the virtual lenslet image using
L v ( i,j,u,v )=Σ k w k L k ( i,j,u,v ) Equation 1:
where
w
k
=
1
-
d
k
∑
k
d
k
,
∑
k
w
k
=
1
,
L v (i,j,u,v) is a pixel value corresponding to i, j, u and v coordinates, w k is a weight value according to a distance between a k-th lenslet image and the virtual lenslet image, and d k is a distance between the k-th lenslet image and the virtual lenslet image.
7 . The light field microscope-based image acquisition apparatus of claim 5 , wherein the 3D conversion processor converts the sub-aperture image into the focal-stack image having 3D information of x, y and z axes, and an x-axis and y-axis position of the focal-stack image includes 2D image information at a corresponding z-axis coordinate point.
8 . The light field microscope-based image acquisition apparatus of claim 7 , wherein
the 3D conversion processor converts the sub-aperture image into the focal-stack image using
A
α
(
s
,
t
,
u
,
v
)
=
A
(
s
+
u
(
1
-
1
α
)
,
Equation
2
t
+
v
(
1
-
1
α
)
,
u
,
ν
)
and
and
F
α
(
x
,
y
)
=
1
N
u
ν
∑
u
′
∑
v
′
A
α
(
x
,
y
,
u
′
,
v
′
)
,
Equation
3
where A α (s.t,u,v) is a converted sub-aperture value corresponding to s, t, u and v coordinates and a specific value of α, F α (x,y) is a focal-stack coordinate value corresponding to the value of α, x, y are x and y coordinate values corresponding to a 3D focal-stack image, and N uv is the number of u and v coordinates.
9 . The light field microscope-based image acquisition apparatus of claim 3 , wherein the disk is connected to an actuator or motor which provides rotational power or linear power.
10 . The light field microscope-based image acquisition apparatus of claim 3 , wherein a linear movement range of the disk is 0 to 500 mm.