Systems and methods for generating depth maps using a camera arrays incorporating monochrome and color cameras
View Patent ↗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.
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.
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.
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.