Image sensor and image sensing method
An image sensor and an image sensing method are provided. The image sensor may restore a high resolution image with respect to a high magnification based on sensing information corresponding to different fields of view (FOVs) and that is received through lens elements having a same focal length and different lens sizes.
1. An image sensor comprising: having a same focal length; and a plurality of sensing elements spaced apart from the lens array by the focal length and configured to sense light passing through the lens array, wherein a lens size a first lens element from among the plurality of lens elements is different from a lens size of a second lens element from among the plurality of lens elements different from the first lens element, wherein each of the plurality of lens elements has a field of view (FOV) given by:
F
O
V
=
2
·
arctan
(
D
F
)
wherein D denotes a size of a sensing region covered by a lens element and F denotes the focal length of the lens element, and
wherein an FOV of a third lens element from among the plurality of lens elements is different from an FOV of a fourth lens element from among the plurality of lens elements different from the third lens element.
2. The image sensor of claim 1 , wherein the plurality of lens elements are classified into a plurality of lens groups based on lens sizes,
wherein each lens group from among the plurality of lens groups corresponds to a respective lens size such that for each lens group from among the plurality of lens groups, lens elements included in the lens group have the corresponding lens size, and
wherein the respective lens size corresponding to each lens group from among the plurality of lens groups is different from respective lens sizes of a-remaining lens groups from among the plurality of lens groups.
3. The image sensor of claim 2 , wherein each lens group from among the plurality of lens groups is configured to cover a same number of sensing elements from among the plurality of sensing elements, and
wherein a number of lens elements included in each lens group from among the plurality of lens groups is determined based on the number of sensing elements that are covered.
4. The image sensor of claim 2 , wherein for each lens group from among the plurality of lens groups, lens elements included in the lens group are located adjacent to each other.
5. The image sensor of claim 2 , wherein one lens group from among the plurality of lens groups comprises a single lens element.
6. The image sensor of claim 1 , wherein the first lens element is located closer to a central position of the lens array than the second lens element, the lens size of the second lens element being greater than the lens size of the first lens element.
7. The image sensor of claim 1 , wherein each of the plurality of lens elements is randomly located with respect to the plurality of sensing elements on a plane corresponding to the lens array.
8. The image sensor of claim 1 , wherein each lens element from among the plurality of lens elements is configured to cover a same number of sensing elements from among the plurality of sensing elements.
9. The image sensor of claim 1 , wherein at least one lens element from among the plurality of lens elements is arranged to cover less than an entire portion of at least one sensing element from among the plurality of sensing elements.
10. The image sensor of claim 1 , further comprising:
a processor configured to restore an image based on sensing information sensed by the plurality of sensing elements so that a resolution of a central region within a FOV of the lens array is higher than a resolution of a region adjacent to the central region.
11. The image sensor of claim 1 , further comprising:
a processor configured to acquire a compound eye vision (CEV) image based on sensing information sensed by the plurality of sensing elements.
12. The image sensor of claim 11 , wherein the processor is further configured to rearrange pixels included in the CEV image based on light field (LF) information sensed by the plurality of sensing elements.
13. The image sensor of claim 11 , wherein the processor is further configured to restore a scene image from the CEV image based on a geometric relationship between the plurality of sensing elements and the plurality of lens elements.
14. The image sensor of claim 11 , wherein the processor is further configured to restore a scene image from the CEV image based on an image restoration model that is completely trained before the CEV image is acquired.
15. The image sensor of claim 1 , further comprising:
a processor configured to select target sensing information from among sensing information sensed by the plurality of sensing elements, the target sensing information corresponding to a zoom factor designated by a user,
wherein the processor is further configured to restore a scene image based on the selected target sensing information.
16. The image sensor of claim 15 , wherein the processor is further configured to select, as the target sensing information, information corresponding to a FOV corresponding to the designated zoom factor.
17. The image sensor of claim 1 , wherein each lens element from among the plurality of lens elements is configured to refract incident light and to form a focal point of light exiting the lens element at a point on a sensing array comprising the plurality of sensing elements.
18. The image sensor of claim 1 , wherein the plurality of lens elements are classified into a plurality of lens groups based on FOV, wherein each lens group from among the plurality of lens groups corresponds to a respective FOV such that the respective FOV corresponding to each lens group from among the plurality of lens groups is different from respective FOVs of remaining lens groups from among the plurality of lens groups, and wherein, for each lens group from among the plurality of lens groups, sensing elements from among the plurality of sensing elements included in a sensing region covered by the lens group are configured to sense rays corresponding to the respective FOV corresponding to the lens group.
19. The image sensor of claim 1 , wherein the image sensor is included in a mobile terminal.
20. The image sensor of claim 1 , wherein light passing through each lens element from among the plurality of lens elements is incident upon at least one sensing element from among the plurality of sensing elements.
21. A camera comprising: a lens array configured to refract incident light rays reflected from an imaging subject; and a sensor configured to sense the light rays refracted by the lens array,
wherein the lens array comprises a first lens having a first diameter and a second lens having a second diameter that is different from the first diameter, wherein each lens of the lens array has a field of view (FOV) given by:
F
O
V
=
2
·
arctan
(
D
F
)
wherein D denotes a size of a sensing region covered by the lens and F denotes a focal length of the lens, and
wherein the lens array comprises a third lens and a fourth lens, the third lens having a different FOV from an FOV of the fourth lens.
22. The camera of claim 21 , wherein the lens array comprises a plurality of first lenses having the first diameter and a plurality of second lenses having the second diameter.
23. The camera of claim 22 , wherein a first area of the sensor covered by the plurality of first lenses and a second area of the sensor covered by the plurality of second lenses have a same size.
24. The camera of claim 22 , wherein the sensor comprises a plurality of sensing elements, and
wherein each of the plurality of first lenses and the plurality of second lenses covers a same number of sensing elements from among the plurality of sensing elements.
25. The camera of claim 24 , wherein the number of sensing elements is a non-integral number.
26. The camera of claim 24 , wherein each sensing element from among the plurality of sensing elements is configured to sense a first light ray reflected from a first point of the imaging subject and a second light ray from a second point of the imaging subject.
27. The camera of claim 25 , wherein the plurality of sensing elements comprises a first sensing element configured to sense a first light ray that has been refracted by the first lens having the first diameter and a second light ray that has been refracted by another lens from among the plurality of first lenses having the first diameter.
28. The camera of claim 22 , wherein the plurality of first lenses corresponds to a first FOV, and wherein the plurality of second lenses corresponds to a second FOV different from the FOV.
29. The camera of claim 21 , wherein light passing through each lens of the lens array is incident upon the sensor.
30. An image sensing method comprising:
sensing, by a plurality of sensing elements, light passing through a plurality of lens elements, each of the plurality of lens elements having a same focal length; and restoring, by a processor, a scene image based on an intensity of the light sensed by the plurality of sensing elements, wherein a lens size of a first lens element from among the plurality of lens elements is different from a lens size of a second lens element from among the plurality of lens elements different from the first lens element, wherein each of the plurality of lens elements has a field of view (FOV) given by:
F
O
V
=
2
·
arctan
(
D
F
)
wherein D denotes a size of a sensing region covered by a lens element and F denotes the focal length of the lens element, and wherein an FOV of a third lens element from among the plurality of lens elements is different from an FOV of a fourth lens element from among the plurality of lens elements different from the third lens element.