Patent US5850486A successfully refreshed from Google Patents.
US5850486A
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Registration of image data
Assignee: McLean Hospital
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Filing: 1996-04-29
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Granted: 1998-12-15
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Expires: 2016-04-29
Abstract
Abstract Registration of images includes rotational and translation correction. Rotational correction includes estimating a rotational-correction angle by polar K-space cross-correlation. K-space regridding is used to rotate an image by the estimated correction angle. Translational correction is obtained by K-space phase-plane conjugation.
Inventors
- 👤 Luis C. Maas, III
- 👤 Blaise deB. Frederick
- 👤 Perry F. Renshaw
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:28
CPC Classifications
G; G06; G06T; G06T3/00; G06T3/02; G06V; G06V10/00; G06V10/20; G06V10/24
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
134 words
A method of rotationally aligning a first image with a second image, wherein the first and second images comprise values that are uniformly spaced on a Cartesian grid, the method comprising: estimating a correction angle to rotationally align the first image with the second image; and rotating the first image by the estimated correction angle by using a regridding technique, wherein the regridding technique comprises: converting the first image from image space to k-space; sampling a convolution of the k-space image and a filter function at coordinates that when rotated by the estimated correction angle map onto a k-space Cartesian grid; assigning values to the k-space Cartesian grid based on the sampled convolution to produce a rotated k-space image; and converting the rotated k-space image into image space to produce the rotated first image.
Claim 2
Independent Claim
134 words
A method of rotationally aligning a first image with a second image, wherein the first and second images comprise values that are uniformly spaced on a Cartesian grid, the method comprising: estimating a correction angle to rotationally align the first image with the second image; and rotating the first image by the estimated correction angle by using a regridding technique, wherein the regridding technique comprises: converting the first image from image space to k-space; sampling a convolution of the k-space image and a filter function at coordinates that when rotated by the estimated correction angle map onto a k-space Cartesian grid; assigning values to the k-space Cartesian grid based on the sampled convolution to produce a rotated k-space image; and converting the rotated k-space image into image space to produce the rotated first image.
Claim 3
Dependent Claim
42 words
The method of claim 1, wherein converting the rotated k-space image comprises dividing an inverse Fourier transform of the rotated k-space image by an inverse Fourier transform of the k-space Cartesian values of the filter function to produce the rotated first image.
Claim 4
Dependent Claim
14 words
The method of claim 1, wherein the filter function is a circularly-symmetric Hamming window.
Claim 5
Dependent Claim
57 words
The method of claim 1, wherein the estimating step comprises: converting the first and second images into first and second k-space polar images; cross-correlating at least a portion of the first k-space polar image with a corresponding portion of the second k-space polar image along the polar angle axis; and determining the correction angle from the cross-correlation.
Claim 6
Dependent Claim
20 words
The method of claim 4, wherein the portions of the k-space polar images are the values at intermediate k-space radii.
Claim 7
Dependent Claim
46 words
The method of claim 4, wherein the converting step comprises: Fourier transforming the first and second images; computing power spectra of the transformed images; and sampling a convolution of each power spectrum with a common filter function at polar coordinates to produce the k-space polar images.
Claim 8
Dependent Claim
27 words
The method of claim 4, wherein the k-space polar images are determined from logarithms of power spectra of the Fourier transforms of the first and second images.
Claim 9
Dependent Claim
39 words
A method of registering a first image with a second image, the method comprising: rotationally aligning the first and second images according to the method of claim 1; and translationally aligning the rotated first image with the second image.
Claim 10
Independent Claim
118 words
A method of translationally aligning a first image with a second image, the method comprising: Fourier transforming the first and second images into k-space to produce first and second k-space images; computing a cross-power spectrum of the first and the second images by multiplying the Fourier transform of the first image by the complex conjugate of the Fourier transform of the second image, the cross-power spectrum having a phase profile; fitting the phase profile of the cross-power spectrum to a k-space phase-plane; multiplying the first k-space image by a k-space phase-plane that is a conjugate of the fitted k-space phase-plane; and inverse Fourier transforming the multiplied k-space image to translationally align the first image with the second image.
Claim 11
Independent Claim
118 words
A method of translationally aligning a first image with a second image, the method comprising: Fourier transforming the first and second images into k-space to produce first and second k-space images; computing a cross-power spectrum of the first and the second images by multiplying the Fourier transform of the first image by the complex conjugate of the Fourier transform of the second image, the cross-power spectrum having a phase profile; fitting the phase profile of the cross-power spectrum to a k-space phase-plane; multiplying the first k-space image by a k-space phase-plane that is a conjugate of the fitted k-space phase-plane; and inverse Fourier transforming the multiplied k-space image to translationally align the first image with the second image.
Claim 12
Dependent Claim
23 words
The method of claim 9, wherein the fitting step comprises performing a least squares regression on the phase values of the cross-power spectrum.
Claim 13
Dependent Claim
28 words
The method of claim 10, wherein the phase values of the cross-power spectrum are weighted by the magnitude values of the cross-power spectrum during the least squares regression.
Claim 14
Dependent Claim
36 words
A method of registering a first image with a second image, comprising: translationally aligning the first and second images according to the method of claim 9; and rotationally aligning the first image with the second image.
Claim 15
Dependent Claim
20 words
Apparatus comprising a computer readable medium storing a program that causes a processor to perform the steps of claim 1.
Claim 16
Dependent Claim
20 words
Apparatus comprising a computer readable medium storing a program that causes a processor to perform the steps of claim 2.
Claim 17
Dependent Claim
20 words
Apparatus comprising a computer readable medium storing a program that causes a processor to perform the steps of claim 9.
Claim 18
Dependent Claim
60 words
A system for processing a series of images, the system comprising: an input port for receiving the series of images; an data storage device, operably coupled with the input port, for storing the images; and a processor, operably coupled with the input port and data storage device, for registering the images; wherein the processor performs the steps of claim 1.
Claim 19
Dependent Claim
60 words
A system for processing a series of images, the system comprising: an input port for receiving the series of images; an data storage device, operably coupled with the input port, for storing the images; and a processor, operably coupled with the input port and data storage device, for registering the images; wherein the processor performs the steps of claim 2.
Claim 20
Dependent Claim
60 words
A system for processing a series of images, the system comprising: an input port for receiving the series of images; an data storage device, operably coupled with the input port, for storing the images; and a processor, operably coupled with the input port and data storage device, for registering the images; wherein the processor performs the steps of claim 9.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-12-14 | 2002-06-15 | 2002-12-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-12-14 | 2006-06-15 | 2006-12-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-12-14 | 2010-06-15 | 2010-12-15 | $7700.00 | Window Closed / Lapsed |