Systems and methods for photometric normalization in array cameras
View Patent ↗Systems and methods for performing photometric normalization in an array camera in accordance with embodiments of this invention are disclosed. The image data of scene from a reference imaging component and alternate imaging components is received. The image data from each of the alternate imaging components is then translated to so that pixel information in the image data of each alternate imaging component corresponds to pixel information in the image data of the reference component. The shifted image data of each alternate imaging component is compared to the image data of the reference imaging component to determine gain and offset parameters for each alternate imaging component. The gain and offset parameters of each alternate imaging component is then applied to the image data of the associate imaging to generate corrected image data for each of the alternate imaging components.
1. A method performed by a processing system to provide a photometric normalization in an array camera having a reference imaging component and a plurality of alternate imaging components associated with the reference imaging component, the method comprising:
receiving image data for a scene captured by the reference imaging component;
receiving image data for a scene captured by each of plurality of alternate imaging components;
determining a nominal parallax for image data of each of the plurality of alternate imaging components that translate information for a particular pixel in the image data of a particular alternate imaging component to a corresponding pixel in the reference imaging component;
applying the nominal parallax of each particular alternate imaging component to the image data of the particular alternate imaging component;
applying a low pass filter to the image data from the reference imaging component and the shifted image data of each particular alternate imaging component; and
computing gain and offset parameters for each particular alternate imaging components from the low pass filtered shifted image data of the particular alternate imaging component and the low pass filtered image data of the reference imaging component.
2. The method of claim 1 further comprising applying the gain and offset parameters of each particular alternate imaging component to the image data captured by the particular alternate imaging component to form photometrically normalized image data for each particular alternate imaging component.
3. The method of claim 2 further comprising determining regions of high contrast in the low pass filtered shifted image data of each particular alternate imaging component.
4. The method of claim 3 further comprising storing determined the regions of high contrast in the low pass filtered image data of each particular alternate imaging component for further correction processing.
5. The method of claim 1 wherein the computing of the gain and offset parameters is performed on a pixel by pixel basis for the image data of each of the plurality of alternate imaging components.
6. The method of claim 1 wherein the computing of the gain and offset parameters is performed on regions of pixels for the image data of each of the plurality of alternate imaging components.
7. The method of claim 1 further comprising:
comparing each gain parameter and each offset parameter for each of the plurality of alternate imaging component to a threshold value; and
setting each gain parameter and each offset parameter determined to at least meet the threshold value to a predetermined value.
8. A system for providing a photometric normalization in an array camera having a reference imaging component and a plurality of alternate imaging components associated with the reference imaging component comprising:
an array camera including a plurality of imaging components that capture image data of a scene including a reference imaging component and plurality of alternate imaging components;
a memory; and
a processor that is configured by instructions stored in the memory to:
receive image data for a scene captured by the reference imaging component,
receive image data for a scene captured by each of plurality of alternate imaging components,
determine a nominal parallax for image data of each of the plurality of alternate imaging components that translate information for a particular pixel in the image data of a particular alternate imaging component to a corresponding pixel in the reference imaging component,
apply the nominal parallax of each particular alternate imaging component to the image data of the particular alternate imaging component,
apply a low pass filter to the image data from the reference imaging component and the shifted image data of each particular alternate imaging component, and
compute gain and offset parameters for each particular alternate imaging components from the low pass filtered shifted image data of the particular alternate imaging component and the low pass filtered image data of the reference imaging component.
9. The system of claim 8 wherein the processor is further configured by the instructions to apply the gain and offset parameters of each particular alternate imaging component to the image data captured by the particular alternate imaging component to form photometrically normalized image data for each particular alternate imaging component.
10. The system of claim 8 wherein the processor is further configured by the instructions to determine regions of high contrast in the low pass filtered shifted image data of each particular alternate imaging component.
11. The system of claim 10 wherein the processor is further configured by the instructions to store the determined regions of high contrast in the low pass filtered image data of each particular alternate imaging component for further correction processing.
12. The system of claim 8 wherein the computing of the gain and offset parameters is performed on a pixel by pixel basis for the image data of each of the plurality of alternate imaging components.
13. The system of claim 9 wherein the computing of the gain and offset parameters is performed on regions of pixels for the image data of each of the plurality of alternate imaging components.
14. The system of claim 8 wherein the processor is further configured by the instructions to:
compare each gain parameter and each offset parameter for each of the plurality of alternate imaging component to a threshold value; and
set each gain parameter and each offset parameter determined to at least meet the threshold value to a predetermined value.
15. A non-transitory medium readable by a processor that stores instructions that when read by the processor configure the processor to perform the method comprising:
receiving image data for a scene captured by the reference imaging component;
receiving image data for a scene captured by each of plurality of alternate imaging components;
determining a nominal parallax for image data of each of the plurality of alternate imaging components that translate information for a particular pixel in the image data of a particular alternate imaging component to a corresponding pixel in the reference imaging component;
applying the nominal parallax of each particular alternate imaging component to the image data of the particular alternate imaging component;
applying a low pass filter to the image data from the reference imaging component and the shifted image data of each particular alternate imaging component; and
computing gain and offset parameters for each particular alternate imaging components from the low pass filtered shifted image data of the particular alternate imaging component and the low pass filtered image data of the reference imaging component.
16. The non-transitory medium of claim 15 wherein the method further comprises applying the gain and offset parameters of each particular alternate imaging component to the image data captured by the particular alternate imaging component to form photometrically normalized image data for each particular alternate imaging component.
17. The non-transitory medium of claim 16 wherein the method further comprises determining regions of high contrast in the low pass filtered shifted image data of each particular alternate imaging component.
18. The non-transitory medium of claim 17 wherein the method further comprises storing determined the regions of high contrast in the low pass filtered image data of each particular alternate imaging component for further correction processing.
19. The non-transitory medium of claim 15 wherein the computing of the gain and offset parameters is performed on a pixel by pixel basis for the image data of each of the plurality of alternate imaging components.
20. The non-transitory medium of claim 15 wherein the computing of the gain and offset parameters is performed on regions of pixels for the image data of each of the plurality of alternate imaging components.
21. The non-transitory medium of claim 15 wherein the method further comprises:
comparing each gain parameter and each offset parameter for each of the plurality of alternate imaging components to a threshold value; and
setting each gain parameter and each offset parameter determined to at least meet the threshold value to a predetermined value.