Wavelength diverse scintillation reduction
View Patent ↗Systems, including apparatus and methods, for obtaining and/or correcting images, particularly from atmospheric and/or other distortions. These corrections may involve, among others, collecting two or more sets of image data corresponding to images of the same scene in different wavelength regimes, and using correlations between wavelength and expected distortion to distinguish apparent image motion due to distortion from apparent image motion due to object or scene motion. These systems may be useful in any suitable imaging context, including navigation, targeting, search and rescue, law enforcement, commercial video cameras and/or surveillance, among others.
1. A method of image correction, comprising:
collecting image data in a range of wavelengths that includes at least a first wavelength and a second wavelength;
processing the image data to determine a first apparent motion map from image data collected at the first wavelength and a second apparent motion map from image data collected at the second wavelength;
processing the first and second apparent motion maps to distinguish changes caused by wavelength-dependent distortion from changes caused by object motion;
generating a first set of corrected image data by removing changes caused by wavelength-dependent distortion from the collected image data; and
generating a first corrected image from the first set of corrected image data.
2. The method of claim 1 , wherein the changes caused by wavelength-dependent distortion comprise apparent image motions, and wherein the step of generating a first set of corrected image data includes removing the apparent image motions from the collected image data while retaining real object motion.
3. The method of claim 1 , further comprising:
generating a second set of corrected image data by removing changes caused by wavelength-dependent distortion from the collected image data; and
generating a second corrected image from the second set of corrected image data.
4. The method of claim 1 , the range of wavelengths including at least a third wavelength, further comprising:
processing the image data to determine a third apparent motion map from image data collected at the third wavelength; and
processing the third apparent motion map, in conjunction with processing the first and second apparent motion maps, to further distinguish changes caused by wavelength-dependent distortion from changes caused by object motion.
5. The method of claim 1 , wherein the step of collecting image data includes collecting image data at a plurality of times corresponding to different image frames.
6. The method of claim 5 , wherein the first apparent motion map is determined by calculating optical flow corresponding to image data collected at the first wavelength at the plurality of times, and wherein the second apparent motion map is determined by calculating optical flow corresponding to image data collected at the second wavelength at the plurality of times.
7. The method of claim 1 , wherein the first wavelength falls within the mid-wave infrared radiation (MWIR) spectrum and the second wavelength falls within the long-wave infrared radiation (LWIR) spectrum.
8. The method of claim 1 , wherein processing the first and second apparent motion maps includes comparing differences in the first and second apparent motion maps with distortion differences expected between image data collected at the first and second wavelengths.
9. The method of claim 1 , further comprising generating a first moving object map corresponding to image data collected at the first wavelength and attributable to object motion, wherein the step of generating the first set of corrected image data includes comparing the first moving object map to the first apparent motion map.
10. The method of claim 9 , further comprising:
generating a second moving object map corresponding to image data collected at the second wavelength and attributable to object motion;
generating a second set of corrected image data by comparing the second moving object map to the second apparent motion map; and
generating a second corrected image from the second set of corrected image data.
11. The method of claim 1 , further comprising providing at least one image-collecting device and a processor, wherein the step of collecting image data is performed using the at least one image-collecting device, and wherein the step of processing is performed using the processor.
12. An image correction system, comprising:
image-collecting apparatus configured to collect a first set of image data in a first wavelength regime and a second set of image data in a second wavelength regime; and
a processor configured to perform first, second, and third processor functionalities;
wherein the first processor functionality involves determining a first apparent motion map from the first set of image data and a second apparent motion map from the second set of image data;
wherein the second processor functionality involves analyzing the first and second apparent motion maps to identify collected image data caused by common path distortion; and
wherein the third processor functionality involves generating a first set of corrected image data by removing common path distortion from the first set of image data, and generating a first corrected image signal from the first set of corrected image data.
13. The system of claim 12 , wherein the third processor functionality is further configured to generate a second set of corrected image data by removing common path distortion from the second set of image data, and to generate a second corrected image signal from the second set of corrected image data.
14. The system of claim 12 , wherein the second processor functionality is configured to identify at least one image characteristic that is a deterministic function of wavelength.
15. The system of claim 12 , further comprising a display configured to present image data output by the processor.