Methods and systems for registering image data
AssigneeThe McLean Hospital Corporation
InventorLuis C. Maas, III
Life of this patent
Estimating the term…
Abstract
Methods and systems for estimating a correction angle that rotationally aligns a first polar centered image with a second polar centered image, wherein the first and second polar centered images includes values on a polar grid having evenly spaced polar angle coordinates for each of at least one radial distance coordinate, include the following steps: calculating a polar cross-power spectrum for the first and second polar centered images, the polar cross-power spectrum comprising a phase profile having at least polar angular frequency coordinates; and fitting a linear function of the angular frequency coordinate to the phase profile of the polar cross-power spectrum to determine the correction angle.
Claims25
A method for rotationally aligning a first image with a second image, the method comprising:
- providing first and second polar centered images related to the first and second images, wherein the first and second polar centered images comprise values on a polar grid having evenly spaced polar angle coordinates for each of at least one radial distance coordinate;
- calculating a polar cross-power spectrum for the first and second polar centered images, the polar cross-power spectrum comprising a phase profile having at least polar angular frequency coordinates;
- fitting a linear function of the angular frequency coordinate to the phase profile of the polar cross-power spectrum to determine a correction angle;
- and
- rotating the first image by the correction angle to rotationally align the first and second images.
A method for aligning a first image with a second image, wherein the first and second images each comprise values on a Cartesian grid, the method comprising:
- calculating power spectra for the first and second images;
- converting the power spectra from Cartesian coordinates to polar coordinates;
- calculating a polar cross-power spectrum for the polar power spectra, the polar cross-power spectrum comprising a phase profile having at least polar angular frequency coordinates;
- fitting a linear function of the polar angular frequency coordinate to the phase profile of the polar cross-power spectrum to determine a correction angle that rotationally aligns the power spectra;
- rotating the first image by the correction angle;
- and
- translationally aligning the rotated first image with the second image.
Dependencies are inferred from the claim text.