Generating high-dynamic range images using varying exposures
Systems and methods are provided for generating high-dynamic range images. In particular, a signal-to-noise (SNR) ratio objective associated with an imaging platform configured to capture one or more images of a region of interest can be determined. The SNR objective can specify a desired signal-to-noise ratio behavior as a function of a brightness of the region of interest. An exposure profile associated with the imaging platform can then be determined based at least in part on the SNR objective. Data indicative of a plurality of image frames, each depicting at least a portion of the region of interest, can then be obtained. The plurality of image frames being captured by the imaging platform in accordance with the exposure profile.
1. A computer-implemented method of creating high-dynamic range images, the method comprising:
determining, by one or more computing devices, a signal-to-noise ratio objective associated with an imaging platform configured to capture one or more images region of interest, the signal-to-noise ratio objective specifying a desired signal-to-noise behavior as a function of a brightness of the region of interest,
wherein the signal-to-noise ratio objective is to shape a signal-to-noise ratio curve based at least in part on a brightness distribution, the one or more computing devices determining the brightness distribution based at least in part on a location of the imaging platform, a location of the sun relative to the earth, an albedo associated with the region of interest, atmospheric absorption, an expected reflectance of one or more targets within the region of interest, or expected atmospheric conditions;
determining, by the one or more computing devices, an exposure profile associated with the imaging platform based at least in part on the signal-to-noise ratio objective;
obtaining, by the one or more computing devices, data indicative of a plurality of image frames, each depicting at least a portion of the region of interest, the plurality of image frames being captured by the imaging platform in accordance with the exposure profile; and
generating, by the one or more computing devices, a high-dynamic range of at least a portion of the region of interest based at least in part on the plurality of image frames.
2. The computer-implemented method of claim 1 , wherein the exposure profile comprises a plurality of integrations times to be used in capturing the plurality of image frames.
3. The computer-implemented method of claim 2 , wherein the exposure profile specifies an integration time for each image frame to be captured.
4. The computer-implemented method of claim 2 , wherein the plurality of integration times are determined to shape a signal-to-noise ratio curve in accordance with the signal-to-noise ratio objective.
5. The computer-implemented method of claim 2 , wherein each image frame of the plurality of image frames is captured using a different integration time from the exposure profile.
6. The computer-implemented method of claim 1 , wherein capturing, by the one or more computing devices, a plurality of image frames depicting the region of interest comprises scanning the region of interest using a two-dimensional image sensor.
7. The computer-implemented method of claim 5 , wherein the two-dimensional image sensor is a two-dimensional staring sensor configured to capture a two-dimensional image frame in a single snapshot.
8. The computer-implemented method of claim 6 , wherein the two-dimensional staring sensor comprises a complementary metal-oxide-semiconductor sensor, a charge coupled device sensor, or an active-pixel sensor.
9. The computer-implemented method of claim 1 , wherein the signal-to-noise ratio objective is to maintain a signal-to-noise ratio curve within a predetermined threshold range.
10. The computer-implemented method of claim 1 , wherein the brightness distribution is determined prior to capturing the plurality of image frames.
11. The computer-implemented method of claim 1 , wherein determining, by the one or more computing devices, a brightness distribution associated with the region of interest comprises determining a brightness distribution associated with at least one image frame of the plurality of image frames.
12. A computing system, comprising: one or more processors; and
one or more memory devices, the one or more memory devices storing computer-readable instructions that when executed by the one or more processors cause the one or more processors to perform operations, the operations comprising:
determining a signal-to-noise ratio objective associated with an imaging platform configured to capture one or more images of a region of interest, the signal-to-noise ratio objective specifying a desired signal-to-noise curve as a function of a brightness of the region of interest,
wherein the signal-to-noise ratio objective is to shape the signal-to-noise ratio curve based at least in part on a brightness distribution, the one or more computing devices determining the brightness distribution based at least in part on a location of the imaging platform, a location of the sun relative to the earth, an expected reflectance of one or more targets within the region of interest, or expected atmospheric conditions;
determining, by the one or more computing devices, an exposure profile associated with the imaging platform based at least in part on the signal-to-noise ratio objective;
obtaining, by the one or more computing devices, data indicative of a plurality of image frames, each depicting at least a portion of the region of interest, the plurality of image frames being captured by the imaging platform in accordance with the exposure profile; and
generating, by the one or more computing devices, a high-dynamic range of at least a portion of the region of interest based at least in part on the plurality of image frames.
13. The computing system of claim 12 , wherein the exposure profile comprises a plurality of integrations times to be used in capturing the plurality of image frames.
14. One or more tangible, non-transitory computer-readable media storing computer-readable instructions that when executed by one or more processors cause the one or more processors to perform operations, the operations comprising:
determining a signal-to-noise ratio objective associated with an imaging platform configured to capture one or more images of a region of interest, the signal-to-noise ratio objective specifying a desired signal-to-noise curve as a function of a brightness of the region of interest,
wherein the signal-to-noise ratio objective is to shape a signal-to-noise ratio curve based at least in part on a brightness distribution, the one or more computing devices determining the brightness distribution based at least in part on a location of the imaging platform, a location of the sun relative to the earth, an expected reflectance of one or more targets within the region of interest, or expected atmospheric conditions;
determining, by the one or more computing devices, an exposure profile associated with the imaging platform based at least in part on the signal-to-noise ratio objective;
obtaining, by the one or more computing devices, data indicative of a plurality of image frames, each depicting at least a portion of the region of interest, the plurality of image frames being captured by the imaging platform in accordance with the exposure profile; and
generating, by the one or more computing devices, a high-dynamic range of at least a portion of the region of interest based at least in part on the plurality of image frames.