Capturing and processing of images including occlusions focused on an image sensor by a lens stack array

• US 9,188,765 B2
• Filed: 05/05/2015
• Issued: 11/17/2015
• Est. Priority Date: 05/20/2008
• Status: Active Grant

• Current Assignee: FotoNation Limited (Adeia Inc.)
• Original Assignee: Pelican Imaging Corporation
• Inventors: Venkataraman, Kartik, Jabbi, Amandeep S., Mullis, Robert H., Duparre, Jacques, Hu, Shane Ching-Feng
• Primary Examiner(s): LAM, HUNG H
• Application Number:
  US14/704,920
• Publication Number:
  US 20150234151A1
• Time in Patent Office: 196 Days
• Field of Search: 348/222.1, 348/229.1, 348/231.2, 348/231.99, 348/234, 348/263, 348/290, 348/335, 348/340, 348/362
• US Class Current: 1/1
• CPC Class Codes: G02B 13/0015 characterised by the lens design
• CPC Class Codes: G02B 3/0056 arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085
• CPC Class Codes: G02B 3/0062 Stacked lens arrays, i.e. refractive surfaces arranged in at least two planes, without structurally separate optical elements in-between
• CPC Class Codes: G02B 5/20 Filters polarising elements G02B5/30
• CPC Class Codes: G02B 5/201 in the form of arrays
• CPC Class Codes: G06T 11/60 Editing figures and text; Combining figures or text
• CPC Class Codes: G06T 19/20 Editing of 3D images, e.g. changing shapes or colours, aligning objects or positioning parts
• CPC Class Codes: G06T 2200/04 involving 3D image data
• CPC Class Codes: G06T 2207/10028 Range image; Depth image; 3D point clouds
• CPC Class Codes: G06T 2207/10052 Images from lightfield camera
• CPC Class Codes: G06T 2207/20221 Image fusion; Image merging
• CPC Class Codes: G06T 7/50 Depth or shape recovery
• CPC Class Codes: G06T 7/557 from light fields, e.g. from plenoptic cameras
• CPC Class Codes: H04N 13/128 Adjusting depth or disparity
• CPC Class Codes: H04N 13/239 using two 2D image sensors having a relative position equal to or related to the interocular distance H04N13/243 takes precedence
• CPC Class Codes: H04N 13/257 Colour aspects
• CPC Class Codes: H04N 2013/0081 Depth or disparity estimation from stereoscopic image signals
• CPC Class Codes: H04N 23/11 for generating image signals from visible and infrared light wavelengths
• CPC Class Codes: H04N 23/13 with multiple sensors
• CPC Class Codes: H04N 23/16 Optical arrangements associated therewith, e.g. for beam-splitting or for colour correction
• CPC Class Codes: H04N 23/45 : for generating image signals from two or more image sensors being of different type or operating in different modes, e.g. with a CMOS sensor for moving images in combination with a charge-coupled device [CCD] for still images
• CPC Class Codes: H04N 23/54 : Mounting of pick-up tubes, electronic image sensors, deviation or focusing coils
• CPC Class Codes: H04N 23/55 : Optical parts specially adapted for electronic image sensors; Mounting thereof
• CPC Class Codes: H04N 23/60 : Control of cameras or camera modules
• CPC Class Codes: H04N 23/69 : Control of means for changing angle of the field of view, e.g. optical zoom objectives or electronic zooming
• CPC Class Codes: H04N 23/698 : for achieving an enlarged field of view, e.g. panoramic image capture
• CPC Class Codes: H04N 23/88 : for colour balance, e.g. white-balance circuits or colour temperature control
• CPC Class Codes: H04N 23/90 : Arrangement of cameras or camera modules, e.g. multiple cameras in TV studios or sports stadiums
• CPC Class Codes: H04N 23/951 : by using two or more images to influence resolution, frame rate or aspect ratio
• CPC Class Codes: H04N 25/131 : including elements passing infrared wavelengths
• CPC Class Codes: H04N 25/133 : including elements passing panchromatic light, e.g. filters passing white light
• CPC Class Codes: H04N 25/135 : based on four or more different wavelength filter elements
• CPC Class Codes: H04N 25/41 : Extracting pixel data from a plurality of image sensors simultaneously picking up an image, e.g. for increasing the field of view by combining the outputs of a plurality of sensors
• CPC Class Codes: H04N 25/48 : Increasing resolution by shifting the sensor relative to the scene
• CPC Class Codes: H04N 25/581 : acquired simultaneously
• CPC Class Codes: H04N 25/60 : Noise processing, e.g. detecting, correcting, reducing or removing noise
• CPC Class Codes: H04N 25/6153 : for colour signals
• CPC Class Codes: H04N 25/67 : applied to fixed-pattern noise, e.g. non-uniformity of response
• CPC Class Codes: H04N 25/705 : Pixels for depth measurement, e.g. RGBZ
• CPC Class Codes: H04N 25/79 : Arrangements of circuitry being divided between different or multiple substrates, chips or circuit boards, e.g. stacked image sensors
• CPC Class Codes: H04N 5/262 : Studio circuits, e.g. for mixing, switching-over, change of character of image, other special effects ; Cameras specially adapted for the electronic generation of special effects
• CPC Class Codes: H04N 5/265 : Mixing

Abstract

Systems and methods for implementing array cameras configured to perform super-resolution processing to generate higher resolution super-resolved images using a plurality of captured images and lens stack arrays that can be utilized in array cameras are disclosed. An imaging device in accordance with one embodiment of the invention includes at least one imager array, and each imager in the array comprises a plurality of light sensing elements and a lens stack including at least one lens surface, where the lens stack is configured to form an image on the light sensing elements, control circuitry configured to capture images formed on the light sensing elements of each of the imagers, and a super-resolution processing module configured to generate at least one higher resolution super-resolved image using a plurality of the captured images.

Claims

1. A camera array, comprising:

a plurality of imagers configured to capture images of a scene, where the plurality of imagers are formed by;

at least one image sensor; and

a lens stack array forming the optics of each of the plurality of imagers, where the optics of each imager comprises at least one lens element and at least one aperture and focuses light onto the image sensor;

an image processing pipeline module configured to process multiple images captured by the plurality of imagers;

wherein the plurality of imagers are configured to capture different images of the same scene;

wherein the images captured by the plurality of imagers include different occlusions sets, where the occlusion set of a given imager is the portion of a scene visible to a baseline imager in the plurality of imagers that is occluded from the view of the given imager; and

wherein the image processing pipeline module is configured to;

determine parallax that yields the highest correlation between pixels from images captured using the same imaging characteristics accounting for the positions of the imagers that captured the images by performing redundant pair-wise measurements between pixels from images captured using the same imaging characteristics to determine pixel correlation for different parallax-induced shifts; and

generate a depth map based upon the measured parallax.

2. The camera array of claim 1, wherein the image processing pipeline module is further configured to determine the parallax that yields the highest correlation between pixels from images captured using the same imaging characteristics accounting for the positions of the imagers that captured the images by keeping track of various pair-wise measurements and calculating a parallax difference that yields the highest pixel correlation ignoring pixels in the images that are in an exposed occlusion set.

3. The camera array of claim 1, wherein the plurality of imagers comprises an array of between 2×

2 and 6×

6 imagers.

4. The camera array of claim 3, wherein the plurality of imagers comprises a 3×

3 array of imagers.

5. The camera array of claim 3, wherein the plurality of imagers comprises a 4×

4 array of imagers.

6. The camera array of claim 3, wherein the plurality of imagers comprises a 5×

5 array of imagers.

7. The camera array of claim 1, wherein the plurality of imagers comprises a one-dimensional array of imagers.

8. The camera array of claim 7, wherein the plurality of imagers comprises at least one selected from the group consisting of:

a 1×

4 array of imagers; and

a 1×

10 array of imagers.

9. The camera array of claim 1, wherein each of the plurality of imagers includes a spectral filter configured to pass a specific spectral band of light selected from the group consisting of a Bayer filter, one or more Blue filters, one or more Green filters, one or more Red filters, one or more shifted spectral filters, one or more near-IR filters, and one or more hyper-spectral filters.

10. The camera array of claim 1, wherein at least two imagers from the plurality of imagers include a Red filter, at least two imagers from the plurality of imagers include a Green filter, and at least two imagers from the plurality of imagers include a Blue filter.

11. The camera array of claim 10, wherein at least two imagers from the plurality of imagers include a near-IR filter.

12. The camera array of claim 1, wherein at least one imager from the plurality of imagers is selected from the group consisting of:

a polychromatic imager; and

a near-IR imager.

13. The array camera of claim 1, wherein the at least one image sensor includes an image sensor that comprises control logic that is a single collection of functions common to all of the plurality of imagers.

14. The array camera of claim 1, wherein the at least one image sensor includes an image sensor that comprises control logic that is common to some of the plurality of imagers with a smaller set of functions applicable to each imager.

15. The camera array of claim 14, wherein the plurality of imagers comprises at least one imager of a first type that includes a spectral filter configured to pass a first spectral band of light and at least one imager of a second type that includes a spectral filter configured to pass a second spectral band of light.

16. The camera array of claim 15, wherein the control logic configures the imagers that include different types of filters to operate with at least one difference in operating parameters.

17. The camera array of claim 16, wherein the at least one difference in operating parameters includes at least one imaging parameter selected from the group consisting of exposure time, gain, and black level offset.

18. The camera array of claim 15, wherein the plurality of imagers comprises a distribution of imagers selected from the group consisting of:

a symmetric distribution of imagers of different types; and

an irregular distribution of imagers of different types.

19. A camera array assembly, comprising:

a plurality of imagers configured to capture images of a scene, where the plurality of imagers are formed by;

an image sensor comprising pixels and control logic that is common to some of the plurality of imagers with a smaller set of functions applicable to each imager; and

a lens stack array forming the optics of each of the plurality of imagers, where the optics of each imager comprises at least one lens element and at least one aperture and focuses light onto the image sensor;

an image processing pipeline module configured to process multiple images captured by the plurality of imagers;

wherein the plurality of imagers are configured to capture different images of the same scene;

wherein the plurality of imagers comprises at least one imager of a first type that includes a spectral filter configured to pass a first spectral band of light and at least one imager of a second type that includes a spectral filter configured to pass a second spectral band of light;

wherein the images captured by the plurality of imagers include different occlusions sets, where the occlusion set of a given imager is the portion of a scene visible to a first of the plurality of imagers that is occluded from the view of the given imager;

wherein the plurality of imagers includes at least one imager of the first type that captures pixels around an edge of a foreground object that is visible to the first of the plurality of imagers and is in the occlusion set of another of the plurality of imagers of the first type; and

wherein the image processing pipeline module is configured to;

determine parallax that yields the highest correlation between pixels from images captured using the same imaging characteristics accounting for the positions of the imagers that captured the images by performing redundant pair-wise measurements between pixels from images captured using the same imaging characteristics to determine pixel correlation for different parallax-induced shifts; and

generate a depth map using the parallax based upon the measured parallax.

20. A camera array assembly, comprising:

a plurality of imagers configured to capture images of a scene, where the plurality of imagers are formed by;

an image sensor comprising pixels and control logic that is a single collection of functions common to all of the plurality of imagers; and

a lens stack array forming the optics of each of the plurality of imagers, where the optics of each imager comprises at least one lens element and at least one aperture and focuses light onto the image sensor;

wherein the plurality of imagers are configured to capture different images of the same scene;

wherein the plurality of imagers comprises at least one imager of a first type that includes a spectral filter configured to pass a first spectral band of light and at least one imager of a second type that includes a spectral filter configured to pass a second spectral band of light;

wherein the images captured by the plurality of imagers include different occlusions sets, where the occlusion set of a given imager is the portion of a scene visible to a first of the plurality of imagers that is occluded from the view of the given imager;

wherein the plurality of imagers includes at least one imager of the first type that captures pixels around an edge of a foreground object that is visible to the first of the plurality of imagers and is in the occlusion set of another of the plurality of imagers of the first type; and

wherein the image processing pipeline module is configured to;

determine parallax that yields the highest correlation between pixels from images captured using the same imaging characteristics accounting for the positions of the imagers that captured the images by performing redundant pair-wise measurements between pixels from images captured using the same imaging characteristics to determine pixel correlation for different parallax-induced shifts; and

generate a depth map based upon the measured parallax.