# US 9,483,816 B2 · Method and system for high accuracy and reliability registration of multi modal imagery > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,483,816 B2 - Document ID: US9483816B2 - Status: Granted - Kind: B2 - Application number: 14/475,102 - Filed: 2014-09-02 - Published: 2015-11-12 - Granted: 2016-11-01 - Earliest claimed: 2013-09-03 - Assignees: Litel Instruments - Applicants: Litel Instruments - Inventors: Adlai H. Smith; Robert O. Hunter, Jr. - Web page: https://patentgrep.com/patent/US9483816B2 ## CPC - G06T 7/00: Image analysis - G06T 7/33: using feature-based methods - G06T 2207/10044: Radar image - G06T 2207/10048: Infrared image - G06T 2207/20021: Dividing image into blocks, subimages or windows - G06T 2207/20076: Probabilistic image processing - G06T 2207/20212: Image combination - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL ## Abstract A method for mapping a target image to a reference image includes receiving a target image; receiving a reference image that overlaps the target image; preprocessing the target image, wherein the preprocessing includes: rejecting a target image with a shadow region above a shadow threshold while keeping a target image with a shadow region below a shadow threshold; providing an uncertainty in a location of the kept target image relative to the reference image; transforming the kept target image to an atlas projection to match the reference image; partitioning the transformed kept target image into a sub-region; and determining a matching statistic for each sub-region to determine a location for each sub-region relative to the reference image. ## Claims ### Claim 1 A non-transitory computer-readable storage medium having instructions stored therein, the instructions executable by a processor to cause the processor to perform operations comprising: receiving a plurality of target images; receiving a reference image that overlaps the plurality of target images; preprocessing the plurality of target images, wherein the preprocessing includes: rejecting one or more first target images of the plurality of target images with a shadow region above a shadow threshold while keeping one or more second target images of the plurality of target images with a shadow region below the shadow threshold; for each second target image: transforming the second target image into an atlas projection to match the reference image; and partitioning the transformed target image into a plurality of sub-regions; determining a matching statistic for each sub-region to determine a location for each sub-region relative to a corresponding portion of the reference image; and determining an alignment of each sub-region with the corresponding portion of the reference image based on the determined matching statistic for each sub-region. ### Claim 2 (depends on 1) The non-transitory computer readable storage medium of claim 1, further comprising determining an offset of the second target image relative to the reference image and an associated uncertainty for the determined offset. ### Claim 3 (depends on 1) The non-transitory computer readable storage medium of claim 1, further comprising: determining an uncertainty for the reference image; and interpolating the reference image to match the second target image orientation and pixel spacing based on the determined uncertainty for the reference image. ### Claim 4 (depends on 1) The non-transitory computer readable storage medium of claim 1, wherein determining the matching statistic for each sub-region includes: selecting one or more basis functions to map a target image amplitude for the sub-region to an amplitude of the reference image. ### Claim 5 (depends on 1) The non-transitory computer readable storage medium of claim 1, further comprising: providing a model for mapping between the second target image and the reference image; and determining an uncertainty in a parameter of the model used for mapping. ### Claim 6 (depends on 1) The non-transitory computer readable storage medium of claim 1, wherein the target image includes one of a synthetic aperture radar (SAR) image, an optical image, an infrared image, a millimeter image, an ultrasonic image, a magnetic resonance imaging (MRI) image, or an x-ray image. ### Claim 7 (depends on 1) The non-transitory computer readable storage medium of claim 1, wherein the reference image includes one of a SAR image, an optical image, an infrared image, a millimeter image, an ultrasonic image, a MRI image, or an X-Ray image. ### Claim 8 An image processing system, comprising: an image acquisition device configured to acquire a plurality of target images and a reference image; and a processor structured to pre-process the plurality of target images, wherein the pre-processing of the target image includes: receiving the plurality of target images; rejecting one or more first target images with a shadow region above a shadow threshold while keeping one or more second target images with a shadow region below the shadow threshold to create a kept target image; providing a model for mapping between the kept target image and the reference image; transforming the kept target image into an atlas projection to match the reference image; partitioning the transformed target image into sub-regions; and determining a fractional area of each sub-region that is shadowed; wherein the processor is structured to pre-process the reference image, wherein the pre-processing of the reference image includes: receiving the reference image; providing a digital elevation map (DEM) of the reference image; projecting the reference image onto a target slant plane, wherein the projection includes a shadow region; and interpolating the projected reference image to match orientation and pixel spacing of the kept target image; wherein the processor is structured to determine a matching statistic for each target image sub-region to determine a location and an alignment for each sub-region relative to a corresponding portion of the received reference image. ### Claim 9 (depends on 8) The image processing system of claim 8, wherein the processor is further structured to determine a shadow area for the received reference image. ### Claim 10 (depends on 9) The image processing system of claim 9, wherein the processor is structured to: select one or more basis functions to map a target image amplitude for each sub-region to an amplitude of the reference image. ### Claim 11 (depends on 8) The image processing system of claim 8, wherein the matching statistic is based on a shadow content of the target image sub-region matching a shadow content of the corresponding portion of the received reference image within a specified tolerance. ### Claim 12 (depends on 8) The image processing system of claim 8, wherein the processor is further structured to determine a model parameter for mapping between the kept target image and the received reference image and to determine an uncertainty with the model parameter. ### Claim 13 (depends on 8) The image processing system of claim 8, wherein the processor is structured to determine a down sampling ratio for the kept target image. ### Claim 14 (depends on 8) The image processing system of claim 8, wherein the received target image includes one of a synthetic aperture radar (SAR) image, an optical image, an infrared image, a millimeter image, an ultrasonic image, a magnetic resonance imaging (MRI) image, or an x-ray image. ### Claim 15 A method of mapping a synthetic aperture radar (SAR) image to a reference image, the method comprising: pre-processing, by a processor, a plurality of target images including: rejecting one or more first target images with a shadow region above a shadow threshold while keeping one or more second target images with a shadow region below the shadow threshold to create a kept target image; partitioning the kept target image into a plurality of sub-regions; and determining a fractional area of each of the plurality of kept target sub-regions that is shadowed; pre-processing, by the processor, the reference image including: projecting the reference image onto a target slant plane, wherein the projection includes a shadow region; and determining a fraction area of the projected reference image that is shadowed; determining, by the processor, a matching statistic for each sub-region that includes: selecting one or more basis functions to map a target image amplitude for each sub-region to a reference image amplitude; providing an upper limit and tolerance for fractional coverage, and providing an upper limit beyond which the sub-region is not considered due to having an excessive shadow region; and determining a location and a normalized mean square error (NMSE) for each considered sub-region based on the matching statistic for each considered sub-region; wherein the determined location of the sub-region corresponds with a shadow content of the sub-region matching a shadow content of the projected reference image within a specified tolerance. ### Claim 16 (depends on 15) The method of claim 15, wherein pre-processing of the kept target image further includes excluding a pixel from the target image based on the pixel representing a bright spot in the target image. ### Claim 17 (depends on 15) The method of claim 15, wherein a target image with an excessive shadow region is a target image that has a greater than or equal to fifty-percent contiguous SAR shadow. ### Claim 18 (depends on 15) The method of claim 15, further comprising determining a model parameter for an offset of the kept target image relative to the projected reference image and an uncertainty in the model parameter. ### Claim 19 (depends on 15) The method of claim 15, wherein the target image includes one of a synthetic aperture radar (SAR) image, an optical image, an infrared image, a millimeter image, an ultrasonic image, a magnetic resonance imaging (MRI) image, or an x-ray image.