System and method for a contiguous support vector machine

• US 20060104519A1
• Filed: 10/28/2005
• Published: 05/18/2006
• Est. Priority Date: 11/03/2004
• Status: Abandoned Application

• Current Assignee: Siemens Medical Solutions USA Incorporated (Siemens AG)
• Original Assignee: Siemens Medical Solutions USA Incorporated (Siemens AG)
• Inventors: Fung, Glenn, Stoeckel, Jonathan
• Application Number:
  US11/262,041
• Publication Number:
  US 20060104519A1
• Time in Patent Office: Days
• US Class Current: 382/224
• CPC Class Codes: G06F 18/254 of classification results, e.g. of results related to same input data
• CPC Class Codes: G06T 2207/30016 Brain
• CPC Class Codes: G06T 7/0012 Biomedical image inspection
• CPC Class Codes: G06T 7/33 using feature-based methods

Abstract

A method of classifying features in digitized images includes providing a plurality of feature points in an n-dimensional space, wherein said feature points have been extracted from a digitized medical image, formulating a support vector machine to classify said feature point into one of two sets, wherein each said feature classification vector is transformed by an adjacency matrix defined by those points that are nearest neighbors of said feature, and solving said support vector machine by a linear optimization algorithm to determine a classifying plane that separates the feature vectors into said two sets.

Claims

1. A method of classifying features in digitized images comprising the steps of:

providing a plurality of feature points in an n-dimensional space, wherein said feature points have been extracted from a digitized medical image;

formulating a support vector machine to classify said feature point into one of two sets, wherein each said feature classification vector is transformed by an adjacency matrix defined by those points that are nearest neighbors of said feature; and

solving said support vector machine by a linear optimization algorithm to determine a classifying plane that separates the feature vectors into said two sets.

2. The method of claim 1, wherein said features are extracted from a plurality of digitized images, wherein each said image comprises a set of intensities defined on a lattice of points, and further comprising spatially registering each of said images by estimating an affine transformation between the images.

3. The method of claim 2, wherein spatially registering said images further comprises registering each image to a single image, registering said single image to a flipped version of itself, and averaging said single image with said flipped version of itself.

4. The method of claim 2, wherein the intensities of each said image are normalized by application of an affine transformation to said intensities.

5. The method of claim 4, wherein said affine transformation parameters are estimated on a training set of features wherein the intensities for each training set point have zero mean and a standard deviation of one.

6. The method of claim 2, wherein the lattice point intensities are used as features.

7. The method of claim 1, wherein said adjacency matrix R is defined by a similarity function r among any two features (f_i, f_j) wherein a matrix element R_ij is defined by R_ij=r(f_i,f_j)ε

{0,1}, i,jε

{1, . . . , n}, wherein n is a number of features.

8. The method of claim 7, wherein the similarity function is defined by a 3%3%3 mask that selects the 26 nearest neighbors of each said feature.

9. The method of claim 1, wherein said features include hypo-perfusion patterns characteristic of Alzhiemer'"'"'s disease.

10. A method of classifying features in digitized images comprising the steps of:

providing a plurality of digitized images, wherein each said image comprises a set of intensities defined on a lattice of points, a

spatially registering each of said images by estimating an affine transformation between the images;

normalizing the intensities of each of said images by application of an affine transformation to said intensities;

extracting a plurality of feature points from said digitized images; and

transforming each said feature by an adjacency matrix R defined by a similarity function r among any two features (f_i,f_j) wherein a matrix element R_ij is defined by R_ij=r(f_i,f_j)ε

{0,1}, i,jε

{1, . . . ,n}, wherein n is a number of features, wherein spatial information is incorporated into each said feature.

11. The method of claim 10, further comprising formulating a formulating a support vector machine to classify said transformed feature point into one of two sets, and solving said support vector machine by a linear optimization algorithm.

12. A program storage device readable by a computer, tangibly embodying a program of instructions executable by the computer to perform the method steps for classifying features in digitized images, said method comprising the steps of:

providing a plurality of feature points in an n-dimensional space, wherein said feature points have been extracted from a digitized medical image;

formulating a support vector machine to classify said feature point into one of two sets, wherein each said feature classification vector is transformed by an adjacency matrix defined by those points that are nearest neighbors of said feature; and

solving said support vector machine by a linear optimization algorithm to determine a classifying plane that separates the feature vectors into said two sets.

13. The computer readable program storage device of claim 12, wherein said features are extracted from a plurality of digitized images, wherein each said image comprises a set of intensities defined on a lattice of points, and further comprising spatially registering each of said images by estimating an affine transformation between the images.

14. The computer readable program storage device of claim 13, wherein spatially registering said images further comprises registering each image to a single image, registering said single image to a flipped version of itself, and averaging said single image with said flipped version of itself.

15. The computer readable program storage device of claim 13, wherein the intensities of each said image are normalized by application of an affine transformation to said intensities.

16. The computer readable program storage device of claim 15, wherein said affine transformation parameters are estimated on a training set of features wherein the intensities for each training set point have zero mean and a standard deviation of one.

17. The computer readable program storage device of claim 13, wherein the lattice point intensities are used as features.

18. The computer readable program storage device of claim 12, wherein said adjacency matrix R is defined by a similarity function r among any two features (f_i,f_j) wherein a matrix element R_ij is defined by R_ij=r(f_i,f_j)ε

{0,1},i,jε

{1, . . . ,n}, wherein n is a number of features.

19. The computer readable program storage device of claim 18, wherein the similarity function is defined by a 3%3%3 mask that selects the 26 nearest neighbors of each said feature.

20. The computer readable program storage device of claim 12, wherein said features include hypo-perfusion patterns characteristic of Alzhiemer'"'"'s disease.