Systems and methods for generating depth maps using a camera arrays incorporating monochrome and color cameras

• US 9,712,759 B2
• Filed: 08/22/2016
• Issued: 07/18/2017
• Est. Priority Date: 05/20/2008
• Status: Active Grant

• Current Assignee: FotoNation Limited (Adeia Inc.)
• Original Assignee: Fotonation Cayman Limited
• Inventors: Venkataraman, Kartik, Jabbi, Amandeep S., Mullis, Robert H.
• Primary Examiner(s): LAM, HUNG H
• Application Number:
  US15/242,598
• Publication Number:
  US 20170006233A1
• Time in Patent Office: 330 Days
• Field of Search: 348 3364, 3482181, 348272-281, 348290-292, 348294, 348335, 348340, 2502081
• CPC Class Codes: G02B 13/0015 characterised by the lens design
• CPC Class Codes: G02B 13/0085 employing wafer level optics
• CPC Class Codes: G02B 27/0025 for optical correction, e.g. distorsion, aberration
• CPC Class Codes: G02B 27/1066 for enhancing image performance, like resolution, pixel numbers, dual magnifications or dynamic range, by tiling, slicing or overlapping fields of view
• CPC Class Codes: G02B 27/123 The splitting element being a lens or a system of lenses, including arrays and surfaces with refractive power
• CPC Class Codes: G02B 3/0006 Arrays G02B3/02, G02B5/188 take precedence
• CPC Class Codes: G02B 5/20 Filters polarising elements G02B5/30
• CPC Class Codes: G02B 5/208 for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation
• CPC Class Codes: G06T 1/20 Processor architectures; Processor configuration, e.g. pipelining
• CPC Class Codes: G06T 2207/10052 Images from lightfield camera
• CPC Class Codes: G06T 2207/30244 Camera pose
• CPC Class Codes: G06T 3/4053 based on super-resolution, i.e. the output image resolution being higher than the sensor resolution
• CPC Class Codes: G06T 7/50 Depth or shape recovery
• CPC Class Codes: G06T 7/55 from multiple images
• CPC Class Codes: G06T 7/557 from light fields, e.g. from plenoptic cameras
• CPC Class Codes: G06T 7/70 Determining position or orientation of objects or cameras camera calibration G06T7/80
• CPC Class Codes: H01L 27/14618 Containers
• CPC Class Codes: H01L 27/14621 Colour filter arrangements
• CPC Class Codes: H01L 27/14625 Optical elements or arrangements associated with the device
• CPC Class Codes: H01L 27/14632 Wafer-level processed structures
• CPC Class Codes: H01L 27/14685 : Process for coatings or optical elements
• CPC Class Codes: H01L 27/14687 : Wafer level processing
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 : Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H04N 1/195 : the array comprising a two-dimensional array or a combination of two-dimensional arrays
• CPC Class Codes: H04N 1/19589 : Optical means, e.g. an optical fibre bundle, for mapping the whole or a part of a scanned image onto the array
• CPC Class Codes: H04N 1/19594 : using a television camera or a still video camera
• CPC Class Codes: H04N 13/128 : Adjusting depth or disparity
• CPC Class Codes: H04N 13/243 : using three or more 2D image sensors
• 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 23/10 : for generating image signals from different wavelengths
• CPC Class Codes: H04N 23/40 : Circuit details for pick-up tubes
• 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 23/60 : 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 23/80 : Camera processing pipelines; Components thereof
• 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 25/00 : Circuitry of solid-state image sensors [SSIS]; Control thereof
• CPC Class Codes: H04N 25/131 : including elements passing infrared wavelengths
• CPC Class Codes: H04N 25/134 : based on three different wavelength filter elements
• 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 25/534 : depending on the spectral component
• 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 25/616 : involving a correlated sampling function, e.g. correlated double sampling [CDS] or triple sampling
• CPC Class Codes: H04N 25/74 : Circuitry for scanning or addressing the pixel array
• 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 5/2621 : Cameras specially adapted for the electronic generation of special effects during image pickup, e.g. digital cameras, camcorders, video cameras having integrated special effects capability
• CPC Class Codes: H04N 5/265 : Mixing
• CPC Class Codes: H04N 5/33 : Transforming infrared radiation cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20

Abstract

A camera array, an imaging device and/or a method for capturing image that employ a plurality of imagers fabricated on a substrate is provided. Each imager includes a plurality of pixels. The plurality of imagers include a first imager having a first imaging characteristics and a second imager having a second imaging characteristics. The images generated by the plurality of imagers are processed to obtain an enhanced image compared to images captured by the imagers. Each imager may be associated with an optical element fabricated using a wafer level optics (WLO) technology.

Claims

1. A camera array, comprising:

a plurality of cameras configured to capture images of a scene;

an image processor configured to process at least a subset of images captured by the plurality of cameras;

wherein the plurality of cameras comprises at least two cameras having different imaging characteristics including at least one monochrome camera and at least one color camera;

wherein the image processor is configured to;

measure parallax within the processed images by detecting parallax-induced changes that are consistent across the images taking into account the position of the cameras that captured the images;

generate a depth map using the measured parallax; and

synthesize an image using the images captured by the at least one monochrome camera and the at least one color camera using the depth map.

2. The camera array of claim 1, wherein the plurality of cameras comprises at least two cameras having different imaging characteristics including different fields of view.

3. The camera array of claim 2, wherein the image processor is configured to synthesize images having different levels of zoom.

4. The camera array of claim 3, further comprising:

a display;

wherein the image processor is configured to synthesize images that smoothly transition from one zoom level to another zoom level when displayed.

5. The camera array of claim 4, wherein the transition is from a zoom level corresponding to a field of view of the widest-angle view camera in the plurality of cameras to a field of view of the camera in the plurality of cameras having the greatest-magnification view.

6. The camera array of claim 3, wherein the image processor is configured to synthesize an image using the images captured by the plurality of cameras and the depth map by mapping pixels from the images captured by the plurality of cameras onto an output image with a size and resolution corresponding to a specific amount of zoom.

7. The camera array of claim 1, wherein the at least one monochrome camera is dedicated to sampling luma and the at least one color camera is dedicated to sampling chroma.

8. The camera array of claim 7, wherein the plurality of cameras comprises a plurality of cameras dedicated to sampling chroma that are arranged symmetrically within the camera array to address occlusion due to parallax.

9. The camera array of claim 1, wherein the at least one color camera includes a Bayer filter.

10. The camera array of claim 9, wherein the at least one monochrome camera includes a sensor and a color filter, where sensor elements on the sensor are associated with the same color filter.

11. The camera array of claim 1, wherein the image processor is configured to select at least one distance as an “

in best focus”

distance and blur an image produced by the camera array based upon estimated distance information.

12. The camera array of claim 1, wherein each camera comprises:

optics comprising at least one lens element and at least one aperture; and

a sensor comprising a two dimensional array of pixels and control circuitry for controlling imaging parameters.

13. The camera array of claim 1, wherein the plurality of cameras comprises at least two cameras having different imaging characteristics including different resolutions.

14. The camera array of claim 1, wherein the plurality of cameras forms a linear array of cameras.

15. The camera array of claim 1, wherein the linear array of cameras is selected from the group consisting of:

a 1×

2 array of cameras;

a 1×

4 array of cameras; and

a 1×

10 array of cameras.

16. The camera array of claim 1, wherein the image processor is further configured to measure parallax within the processed images by ignoring pixels in the images captured by the plurality of cameras that are in an exposed occlusion set.

17. The camera array of claim 1, wherein the cameras having different imaging characteristics are configured to operate with at least one difference in operating parameters selected from the group consisting of exposure time, gain, and black level offset.

18. The camera array of claim 1, wherein the camera array is a monolithic camera array assembly comprising:

a lens element array forming the optics of each camera; and

a single semiconductor substrate on which pixels and control circuitry for each camera are formed.

19. The camera array of claim 1, wherein the plurality of cameras are formed on separate semiconductor substrates.

21. The camera array of claim 1, wherein the image processor is configured to measure parallax for pixels within the processed images by calculating a parallax difference that yields the highest pixel correlation.

22. The camera array of claim 21, wherein the parallax difference that yields the highest pixel correlation is determined by keeping track of various pair-wise measurements.

23. The camera array of claim 22, wherein the image processor is configured to calculate a parallax difference that yields the highest pixel correlation by ignoring pixels in the images that are in an exposed occlusion set.

24. The camera array of claim 23, wherein the measured parallax is measured with sub-pixel precision.

25. The camera array of claim 21, wherein the measured parallax is measured with sub-pixel precision.

26. The camera array of claim 1, wherein the measured parallax is measured with sub-pixel precision.

20. A camera array, comprising:

a plurality of cameras formed on separate semiconductor substrates and configured to capture images of a scene;

an image processor configured to process at least a subset of images captured by the plurality of cameras;

wherein the plurality of cameras comprises at least two cameras having different imaging characteristics including at least one monochrome camera and at least one color camera, where;

the at least one color camera includes a Bayer filter; and

the at least one monochrome camera includes a sensor and a color filter,

where sensor elements on the sensor are associated with the same color filter;

wherein the cameras having different imaging characteristics are configured to operate with at least one difference in operating parameters; and

wherein the image processor is configured to;

measure parallax within the processed images by detecting parallax-induced changes that are consistent across the images taking into account the position of the cameras that captured the images;

generate a depth map using the measured parallax; and

synthesize an image using the images captured by the at least one monochrome camera and the at least one color camera using the depth map; and

select at least one distance as an “

in best focus”

distance and blur the synthesized image based upon the depth map.