US20030142877A1 — Imaging using a multifocal aspheric lens to obtai…

Claim 1

Independent Claim 55 words

1 . A system for imaging one or more objects comprising: means for capturing an image of at least one object through a circularly symmetric, multifocal aspheric lens to provide a blurred image; and means for processing the captured blurred image to provide a recovered image of the object having an extended depth of field.

Claim 2

Dependent Claim 55 words

1 . A system for imaging one or more objects comprising: means for capturing an image of at least one object through a circularly symmetric, multifocal aspheric lens to provide a blurred image; and means for processing the captured blurred image to provide a recovered image of the object having an extended depth of field.

Claim 3

Dependent Claim 51 words

2 . The system according to claim 1 wherein said object represents a three-dimensional object which extends over a range of distance, and said extended depth of field is characterized by at least a substantial portion of the object being in focus in said recovered image over said range of distance.

Claim 4

Dependent Claim 68 words

3 . The system according to claim 2 wherein said lens has a radius and annular portions of continuously varying focal length in accordance with said radius of the lens, in which said object at each distance in said range is in focus by at least one of said annular portions of said lens, and said object is blurred by other of said annular portions of said lens.

Claim 5

Dependent Claim 33 words

4 . The system according to claim 1 wherein said lens has a radius and said lens is multifocal by having a focal length which continuously varies with the radius of said lens.

Claim 6

Dependent Claim 197 words

5 . The system according to claim 1 wherein said lens is characterized by the equation: φ  ( r ) =  - { 2   π λ 0  ( r 2 + t 2 - t ) + π λ 0  R 2 s 2 - s 1  [ ln  { 2  s 2 - s 1 R 2 [ r 2 + ( s 1 + s 2 - s 1 R 2  r 2 ) 2 +  ( s 1 + s 2 - s 1 R 2  r 2 ) ] + 1 } - ln  ( 4  s 2 - s 1 R 2  s 1 + 1 ) ] } .  where, φ(r) is the phase delay for radius r of the lens to within an arbitrary constant, said range is over distances s 1 through s 2 , R is the outer radius of the lens, t is the distance from the plane where the lens is disposed to the plane of image capture by said capturing means, and λ 0 is the free space wavelength.

Claim 7

Dependent Claim 47 words

6 . The system according to claim 1 wherein said blurred image represents an array of pixel values, and said processing means applies a convolution matrix to said array of pixel values in accordance with the point spread function of said lens to provide said recovered image.

Claim 8

Dependent Claim 18 words

7 . The system according to claim 6 wherein said convolution matrix is substantially an edge sharpening filter.

Claim 9

Dependent Claim 30 words

8 . The system according to claim 1 wherein said means for processing the blurred image utilizes one of an inverse filter or maximum entropy to provide said recovered image.

Claim 10

Dependent Claim 24 words

9 . The system according to claim 1 wherein said processing means is operative in accordance with the point spread function of the lens.

Claim 11

Dependent Claim 16 words

10 . The system according to claim 1 wherein said processing means represents a computer system.

Claim 12

Dependent Claim 16 words

11 . The system according to claim 1 further comprising means for outputting said recovered image.

Claim 13

Dependent Claim 15 words

12 . The system according to claim 11 wherein said outputting means represents a display.

Claim 14

Dependent Claim 17 words

13 . The system according to claim 1 wherein said lens is provided by one optical element.

Claim 15

Dependent Claim 21 words

14 . The system according to claim 1 wherein said lens is provided by an optical system having multiple optical elements.

Claim 16

Dependent Claim 22 words

15 . The system according to claim 14 wherein said multiple optical elements represent a multi-focal phase plate and an objective lens.

Claim 17

Dependent Claim 40 words

16 . The system according to claim 1 wherein said capturing means comprises a camera which captures said blurred image through at least said lens, and said camera further comprises means for providing said blurred image to said processing means.

Claim 18

Dependent Claim 39 words

17 . The system according to claim 16 wherein said providing means comprises removable memory in said camera for storing said blurred image, and said processing means comprises means for accessing said removable memory and retrieving said blurred image.

Claim 19

Dependent Claim 36 words

18 . The system according to claim 16 wherein said providing means comprises one of a cable or optical connection between said camera and said processing means for transferring said blurred image to said processing means.

Claim 20

Dependent Claim 18 words

19 . The system according to claim 16 wherein said camera represents a digital still or video camera.

Claim 21

Dependent Claim 47 words

20 . The system according to claim 16 wherein said camera represents a digital video camera providing successive ones of said blurred images to said processing means, and said processing means processes each of said successive ones of said blurred images to provide corresponding successive recovered images.

Claim 22

Dependent Claim 27 words

21 . The system according to claim 16 wherein said camera has at least one photodetector array to capture said blurred image through at least said lens.

Claim 23

Dependent Claim 42 words

22 . The system according to claim 1 wherein said capturing means comprises a camera which captures said blurred image through at least said lens, and said camera further comprises said processing means to provide said recovered image from said blurred image.

Claim 24

Dependent Claim 17 words

23 . The system according to claim 22 wherein said lens represents one or more optical elements.

Claim 25

Dependent Claim 19 words

24 . The system according to claim 22 wherein said camera has a display for outputting said recovered image.

Claim 26

Dependent Claim 18 words

25 . The system according to claim 22 wherein said camera represents a digital still or video camera.

Claim 27

Dependent Claim 49 words

26 . The system according to claim 22 wherein said processing means represents a microprocessor-based system in said camera to provide said recovered image from said blurred image, and said camera has memory for storing said blurred image, said recovered image, or both said blurred image and recovered image.

Claim 28

Dependent Claim 27 words

27 . The system according to claim 22 wherein said camera has at least one photodetector array to capture said blurred image through at least said lens.

Claim 29

Dependent Claim 68 words

28 . The system according to claim 1 wherein said capturing means represents a camera for recording on film said blurred image captured through at least said lens, and means for digitizing one of a print or negative representing said blurred image recorded on said film to provided a digitized blurred image, in which said processing means operatives upon said digitized blurred image to provide said recovered image.

Claim 30

Dependent Claim 47 words

29 . The system according to claim 1 wherein said capturing means comprises at least one CCD providing an array of pixels to record the blurred image, wherein each pixel has a size, and said imaging resolution of said system depends on said size of said pixel.

Claim 31

Dependent Claim 14 words

30 . The system according to claim 1 wherein said lens is diffraction limited.

Claim 32

Dependent Claim 27 words

31 . The system according to claim 1 wherein said lens provides two or more distances of operation of said system with respect to said capturing means.

Claim 33

Dependent Claim 18 words

32 . The system according to claim 1 wherein said lens is characterized by a logarithmic phase function.

Claim 34

Dependent Claim 45 words

33 . The system according to claim 5 wherein different ones of said lens characterized by φ(r) are provided by changing the weighting of the ratio r/R to effect the rate of change of focal length of said lens with the radius of said lens.

Claim 35

Dependent Claim 29 words

34 . The system according to claim 15 wherein angular field of view of capturing means is in accordance with the angular field of view of the objective lens.

Claim 36

Dependent Claim 50 words

35 . A method for imaging one or more three-dimensional objects comprising the steps of: imaging at least one object through a circularly symmetric aspheric lens to provide a blurred image; and processing said blurred image to provide a recovered image of the object having an extended depth of field.

Claim 37

Dependent Claim 50 words

35 . A method for imaging one or more three-dimensional objects comprising the steps of: imaging at least one object through a circularly symmetric aspheric lens to provide a blurred image; and processing said blurred image to provide a recovered image of the object having an extended depth of field.

Claim 38

Dependent Claim 51 words

36 . The method according to claim 35 wherein said object represents a three-dimensional object which extends over a range of distances, and said extended depth of field is characterized by at least a substantial portion of the object being in focus in said recovered image over said range of distances.

Claim 39

Dependent Claim 68 words

37 . The method according to claim 36 wherein said lens has a radius and annular portions of continuously varying focal length in accordance with said radius of the lens, in which said object at each distance in said range is in focus by at least one of said annular portions of said lens, and said object is blurred by other of said annular portions of said lens.

Claim 40

Dependent Claim 33 words

38 . The method according to claim 35 wherein said lens has a radius and said lens is multifocal by having a focal length which continuously varies with the radius of said lens.

Claim 41

Dependent Claim 197 words

39 . The method according to claim 35 wherein said lens is characterized by the equation: φ  ( r ) =  - { 2   π λ 0  ( r 2 + t 2 - t ) + π λ 0  R 2 s 2 - s 1  [ ln  { 2  s 2 - s 1 R 2 [ r 2 + ( s 1 + s 2 - s 1 R 2  r 2 ) 2 +  ( s 1 + s 2 - s 1 R 2  r 2 ) ] + 1 } - ln  ( 4  s 2 - s 1 R 2  s 1 + 1 ) ] } .  where, φ(r) is the phase delay for radius r of the lens to within an arbitrary constant, said range is over distances s 1 through s 2 , R is the outer radius of the lens, t is the distance from the plane where the lens is disposed to the plane of image capture by said capturing means, and λ 0 is the free space wavelength.

Claim 42

Dependent Claim 21 words

40 . The method according to claim 35 wherein said processing step utilizes a convolution matrix to provide the recovered image.

Claim 43

Dependent Claim 17 words

41 . The method according to claim 40 wherein said convolution matrix represents an edge sharpening filter.

Claim 44

Dependent Claim 25 words

42 . The method according to claim 35 wherein said processing step utilizes one of inverse filtering or maximum entropy to provide the recovered image.

Claim 45

Dependent Claim 17 words

43 . The method according to claim 35 further comprising the step of displaying said recovered image.

Claim 46

Dependent Claim 19 words

44 . The method according to claim 35 wherein said lens is provides by one or more optical elements.

Claim 47

Dependent Claim 24 words

45 . The method according to claim 35 wherein said lens represents an optical system having a multi-focal phase plate and an objective lens.

Claim 48

Dependent Claim 31 words

46 . The method according to claim 35 wherein said capturing step is carried out with the aid of a camera which records said blurred image through at least said lens.

Claim 49

Dependent Claim 18 words

47 . The method according to claim 46 wherein said processing step is carried out in said camera.

Claim 50

Dependent Claim 23 words

48 . The method according to claim 46 wherein said camera represents one of a digital still imaging camera or digital video camera.

Claim 51

Dependent Claim 47 words

49 . The method according to claim 46 wherein said camera represents a digital video camera providing successive ones of said blurred images to said processing step, and said processing step processes each of said successive ones of said blurred images to provide corresponding seccessive recovered image.

Claim 52

Dependent Claim 70 words

50 . The method according to claim 46 wherein said camera records on film said blurred image captured through at least said lens, and said method further comprises the step of digitizing one of a print or negative representing said blurred image recorded on said film to provided a digitized blurred image, in which said processing step is carried out using said digitized blurred image to provide said recovered image.

Claim 53

Dependent Claim 26 words

51 . The method according to claim 46 wherein said lens provides two or more distances from said camera where said recovered image is in focus.

Claim 54

Dependent Claim 19 words

52 . The method according to claim 35 wherein said processing step is carried out by a computer system.

Claim 55

Dependent Claim 24 words

53 . The method according to claim 35 wherein said processing step is carried in accordance with the point spread function of the lens.

Claim 56

Dependent Claim 46 words

54 . The method according to claim 35 wherein said capturing step utilizes at least one CCD providing an array of pixels to record the blurred image, wherein each pixel has a size, and said resolution of said system depends on said size of said pixel.

Claim 57

Dependent Claim 14 words

55 . The method according to claim 35 wherein said lens is diffraction limited.

Claim 58

Dependent Claim 29 words

56 . The method according to claim 45 wherein angular field of view of capturing means is in accordance with the angular field of view of the objective lens.

Claim 59

Dependent Claim 49 words

57 . A smart camera comprising: optics having circularly symmetric multiple focal lengths; at least one detector array for capturing an image through said optics to provide a blurred image; and means for processing the captured blurred image to provide a recovered image having all extended depth of field.

Claim 60

Dependent Claim 49 words

57 . A smart camera comprising: optics having circularly symmetric multiple focal lengths; at least one detector array for capturing an image through said optics to provide a blurred image; and means for processing the captured blurred image to provide a recovered image having all extended depth of field.

Claim 61

Dependent Claim 19 words

58 . The camera according to claim 57 wherein said optics is provided by a circularly symmetric aspheric lens.

Claim 62

Dependent Claim 22 words

59 . The camera according to claim 57 wherein said optics is provided by an objective lens and a multi-focal phase plate.

Claim 63

Dependent Claim 23 words

60 . The camera according to claim 57 wherein said optics is provided by an objective lens and a circularly symmetric aspheric lens.

Claim 64

Dependent Claim 23 words

61 . The camera according to claim 57 wherein said detector array represents one of a CCD array, CMOS array, or CID array.

Claim 65

Dependent Claim 40 words

62 . The camera according to claim 57 wherein said lens has a point spread function, and said processing means operates upon said blurred image in accordance with said point spread function of said lens to provide said recovered image.

Claim 66

Dependent Claim 32 words

63 . The camera according to claim 57 wherein said processing means utilizes one of an inverse filtering, convolution matrix, or maximum entropy upon the blurred image to provide the recovered image.

Claim 67

Dependent Claim 21 words

64 . The camera accordingly to claim 62 wherein said lens is diffraction limited in accordance with said point spread function.

Claim 68

Dependent Claim 41 words

65 . An imaging system comprising: means for capturing an image through a circularly symmetric, multifocal lens to provide a blurred image; and means for processing the captured blurred image to provide a recovered image having an extended depth of field.

Claim 69

Dependent Claim 41 words

65 . An imaging system comprising: means for capturing an image through a circularly symmetric, multifocal lens to provide a blurred image; and means for processing the captured blurred image to provide a recovered image having an extended depth of field.

Claim 70

Dependent Claim 36 words

66 . An imaging apparatus comprising: means for processing a blurred image, which was captured through a circularly symmetric, multifocal lens, to provide a recovered image in accordance with the point spread function of said lens.

Claim 71

Dependent Claim 36 words

66 . An imaging apparatus comprising: means for processing a blurred image, which was captured through a circularly symmetric, multifocal lens, to provide a recovered image in accordance with the point spread function of said lens.

Claim 72

Dependent Claim 33 words

67 . The imaging apparatus according to claim 66 wherein said processing mean utilizes one of an inverse filter, convolution matrix, or maximum entropy upon said blurred image to provide said recovered image.

Claim 73

Dependent Claim 17 words

68 . A multifocal optical element comprising a body which is characterized by a logarithmic phase function.

Claim 74

Dependent Claim 17 words

68 . A multifocal optical element comprising a body which is characterized by a logarithmic phase function.

Claim 75

Dependent Claim 20 words

69 . The optical element according to claim 68 wherein said body represents one of a lens and a phase-plate.

Claim 76

Dependent Claim 17 words

70 . The optical element according to claim 68 wherein said body is circularly symmetric and aspheric.

Claim 77

Dependent Claim 200 words

71 . The optical element according to claim 68 wherein said logarithm phase function is provided by φ(r) in accordance with the equation: φ  ( r ) = - { 2  π λ 0  ( r 2 + t 2 - t ) + π λ 0  R 2 s 2 - s 1 [ ln  { 2  s 2 - s 1 R 2  [ r 2 + ( s 1 + s 2 - s 1 R 2  r 2 ) 2 + ( s 1 + s 2 - s 1 R 2  r 2 ) ] + 1 } - ln  ( 4  s 2 - s 1 R 2  s 1 + 1 ) ] } . where, φ(r) is the phase delay for radius r of the lens to within an arbitrary constant, said range is over distances s 1 through s 2 , R is the outer radius of the lens, t is the distance from the plane where the lens is disposed to the plane of image capture by said capturing means, and λ 0 is the free space wavelength.

Claim 78

Dependent Claim 46 words

72 . The optical element according to claim 71 wherein different ones of said lens characterized by φ(r) are provided by changing the weighting of the ratio r/R to effect the rate of change of focal length of said lens with the radius of said lens.

Imaging using a multifocal aspheric lens to obtain extended depth of field

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