Capturing and processing of images including occlusions captured by heterogeneous camera arrays
View Patent ↗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. Lens stack arrays in accordance with many embodiments of the invention include lens elements formed on substrates separated by spacers, where the lens elements, substrates and spacers are configured to form a plurality of optical channels, at least one aperture located within each optical channel, at least one spectral filter located within each optical channel, where each spectral filter is configured to pass a specific spectral band of light, and light blocking materials located within the lens stack array to optically isolate the optical channels.
1. A camera array, comprising:
a plurality of imagers, where each imager comprises:
optics comprising at least one lens element and at least one aperture that form an optical channel;
a sensor comprising a two dimensional array of pixels and control circuitry for controlling imaging parameters; and
at least one spectral filter located within the imager, where each spectral filter is configured to pass a specific spectral band of light;
wherein the plurality of imagers are configured to capture images of the same scene;
wherein the shape of at least one lens element of an imager of a first type that includes a spectral filter configured to pass a first spectral band of light differs from the shape of at least one lens element forming a second optical channel for an 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 baseline imager in the plurality of imagers that is occluded from the view of the given imager; and
wherein the plurality of imagers includes a first imager that captures pixels around an edge of a foreground object that is visible to the baseline imager and is in the occlusion set of a second of the plurality of imagers that has the same imaging characteristics as the first imager.
2. The camera array of claim 1 , wherein the imager array further comprises an image processing module configured to reconstruct color information around the edge of the foreground object that is visible to the baseline imager and in the occlusion set of the second of the plurality of imagers using the pixels captured by the first imager.
3. The camera array of claim 1 , wherein the prescription of at least one surface of a lens element in an imager is a function of the specific spectral band of light passed by the spectral filter within the imager.
4. The camera array of claim 3 , wherein the radii of curvature of the lens surfaces differ based upon the specific spectral band of light passed by the spectral filter within the imager.
5. The camera array of claim 1 , wherein each lens surface is selected from the group consisting of diffractive, Fresnel, refractive and combinations thereof.
6. The camera array of claim 1 , wherein at least one lens element in the optical channel of an imager is a negative lens element, and the negative lens element is proximate the image formed by the optical channel.
7. The camera array of claim 1 , wherein the camera array comprises an array of between 2×2 and 6×6 imagers.
8. The camera array of claim 1 , wherein the camera array comprises a one-dimensional array of imagers.
9. The camera array of claim 8 , wherein the camera array comprises at least one selected from the group consisting of: a 1×4 array of imagers;
and a 1×10 array of imagers.
10. The camera array of claim 1 , wherein each imager includes a filter selected from the group consisting of a Bayer filter, one or more Blue filters, one or amore 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.
11. The camera array of claim 1 , wherein at least two imagers include a Red filter, at least two imagers include a Green filter, and at least two imagers include a Blue filter.
12. The camera array of claim 11 , wherein at least two imagers include a near-IR filter.
13. The camera array of claim 1 , wherein each spectral filter is selected from the group consisting of an organic color filter, an absorptive material, a dielectric coating, an interference filter, a multilayer coating, and combinations thereof.
14. The camera array of claim 1 , wherein the at least one spectral filter within an optical channel of an imager is located so that the spectral filter is proximate the aperture stop.
15. The camera array of claim 1 , wherein the at least one spectral filter within an optical channel of an imager is disposed on the surface of a lens element in the lens stack of the imager.
16. The camera array of claim 1 , wherein the control circuitry of the imagers including different types of filters configures the imagers to operate with at least one difference in operating parameters.
17. The camera array of claim 1 , 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.
18. The camera array of claim 1 , wherein the plurality of imagers are configured to form images of an object space within a scene that yield non-redundant information about the object space within the sampled scene.
19. A camera array assembly, comprising:
a monolithic integrated module forming a plurality of imagers, where each imager comprises:
a lens stack array comprising an array of optical channels that form the optics of each imager, where each optical channel comprises at least one lens element and at least one aperture forming a lens stack;
light blocking materials located within the lens stack array to optically isolate the optical channels;
a single semiconductor substrate on which all of the pixels and control circuitry for each imager are formed; and
at least one spectral filter located within each imager, where each spectral filter is configured to pass a specific spectral band of light;
wherein the plurality of imagers are configured to capture 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 control circuitry of the imagers including different types of filters configures the imagers to operate with at least one difference in operating parameters;
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; and
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.
20. A camera array, comprising:
a plurality of imagers formed on separate semiconductor substrates, where each imager comprises:
optics comprising at least one lens element and at least one aperture that form an optical channel;
a sensor comprising a two dimensional array of pixels and control circuitry for controlling imaging parameters; and
at least one spectral filter located within the imager, where each spectral filter is configured to pass a specific spectral band of light;
wherein the plurality of imagers are configured to capture 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 control circuitry of the imagers including different types of filters configures the imagers to operate with at least one difference in operating parameters;
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 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.