Method & system for high accuracy & reliability registration of multi modal imagery

An image processing system, comprising:

• an image acquisition device configured to acquire a target image and a reference image;
• and
• a processor structured to pre-process the target image, wherein the pre-processing of the target image includes:
• receiving the target image;
• rejecting a target image with a shadow region above a shadow threshold while keeping a target image 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 kept 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 target image;
• wherein the processor is structured to determine a matching statistic for each target image sub-region to determine a location for each sub-region relative to the reference image.

A method of mapping a synthetic aperture radar (SAR) image to a reference image, the method comprising:

• pre-processing, by a processor, a target image including:
• rejecting a target image with a shadow region above a shadow threshold while keeping a target image with a shadow region below the shadow threshold to create a kept target image;
• partitioning the kept target image into a sub-region;
• and
• determining a fractional area of the kept target sub-region that is shadowed;
• pre-processing, by the processor, a 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 reference image that is shadowed;
• determining, by the processor, a matching statistic for each sub-region that includes:
• selecting a fixed form for the reference image with no free parameters;
• selecting one or more basis functions to map a target image amplitude for the sub-region to a reference image amplitude;
• providing an upper limit and tolerance for fractional coverage, and providing an upper limit beyond which a target 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 target 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 reference image within a specified tolerance.