Method for registering images in a radiography application
View Patent ↗An image registration method is described for X-ray imagery, in which specific views of the x-rays are provided to optimize tie point selection accuracy and efficiency. The first view maintains context during initial point selection. The second view provides a detailed view of each point pair, to allow for fine adjustment, while automatically presenting each point pair in sequence to the user. After the tie points are refined and the images are registered, a third view is provided which allows direct comparison of the registered images.
1. A method for placing and confirming reference points associated with image registration for a radiographic image processing application, wherein the reference points identify similar image positions in separate images of substantially the same object, said method comprising the steps of:
obtaining first and second radiographic images representing substantially the same object taken at different times;
presenting a “zoomed out” view of the full extent of the first and second radiographic images side by side in a first graphical user interface view in order to allow a user to place potential reference points in their approximate locations on each image, all the while maintaining context for the user;
presenting a “zoomed in” view of an area of the first and second images around each of the potential tie points in a second graphical user interface view to allow the user to refine the placement of the potential reference points, thereby enabling the generation of refined reference points suitable for registration;
registering the first and second images by utilizing the refined reference points, thereby producing first and second registered images; and
utilizing the registered images in a third graphical user interface view to indicate the amount of mismatch between the first and second images.
2. The method as claimed in claim 1 wherein the step of presenting a “zoomed out” view of the full extent of the two images side by side in a first view comprises constraining the user to locate a corresponding point in the second image after locating a point in the first image.
3. The method as claimed in claim 1 wherein the step of utilizing the registered images in a third view comprises alternately overlaying the first and second registered images in the third view to indicate the amount of mismatch between the pair of images.
4. The method as claimed in claim 1 wherein the step of overlaying the registered images in the third view causes the mismatch to appear as an image comparison.
5. The method as claimed in claim 1 wherein the step of utilizing the registered images in a third view comprises presenting the first and second registered images side by side in the third view synchronized in terms of zoom level, image center, and cursor position, whereby a position of a first cursor on a point of interest in the first image automatically positions a second cursor over the corresponding point of interest in the second image.
6. The method as claimed in claim 1 wherein the step of registering the first and second images comprises producing a polynomial correlation between the refined reference points of the two images and warping the two images until two registered images are obtained.
7. The method as claimed in claim 1 further comprising the step of processing the first and second registered images to provide a difference image indicative of change between the images.
8. A method for placing and confirming reference points associated with image registration for an intra-oral image processing application, wherein the reference points identify similar image positions in separate images of substantially the same object, said method comprising the steps of:
obtaining first and second intra-oral images representing substantially the same object taken at different times;
presenting a “zoomed out” view of the full extent of the first and second intra-oral images side by side in a first graphical user interface view in order to allow a user to place potential reference points in their approximate locations on each image, all the while maintaining context for the user;
presenting a “zoomed in” view of an area of the first and second images around each of the potential tie points in a second graphical user interface view to allow the user to refine the placement of the potential reference points, thereby enabling the generation of refined reference points suitable for registration;
registering the first and second images by utilizing the refined reference points, thereby producing first and second registered images; and
utilizing the registered images in a third graphical user interface view to indicate the amount of mismatch between the first and second images.
9. The method as claimed in claim 8 wherein the step of presenting a “zoomed out” view of the full extent of the two images side by side in a first view comprises constraining the user to locate a corresponding point in the second image after locating a point in the first image.
10. The method as claimed in claim 8 wherein the step of utilizing the registered images in a third view comprises alternately overlaying the first and second registered images in the third view to indicate the amount of mismatch between the pair of images.
11. The method as claimed in claim 8 wherein the step of registering the first and second images comprises producing a polynomial correlation between the refined reference points of the two images and warping the two images until two registered images are obtained.
12. The method as claimed in claim 8 further comprising the step of processing the first and second registered images to provide a difference image indicative of change between the images.
13. A computer program product for placing and confirming reference points associated with image registration for a radiographic image processing application, wherein the reference points identify similar image positions in separate first and second radiographic images representing substantially the same object taken at different times, said computer program product comprising: a computer readable storage medium having a computer program stored thereon for performing the steps of:
presenting a “zoomed out” view of the full extent of the first and second radiographic images side by side in a first graphical user interface view in order to allow a user to place potential reference points in their approximate locations on each image, all the while maintaining context for the user;
presenting a “zoomed in” view of an area of the first and second images around each of the potential tie points in a second graphical user interface view to allow the user to refine the placement of the potential reference points, thereby enabling the generation of refined reference points suitable for registration;
registering the first and second images by utilizing the refined reference points, thereby producing first and second registered images; and
utilizing the registered images in a third graphical user interface view to indicate the amount of mismatch between the first and second images.
14. The computer program product as claimed in claim 13 wherein the step of presenting a “zoomed out” view of the full extent of the two images side by side in a first view comprises constraining the user to locate a corresponding point in the second image after locating a point in the first image.
15. The computer program product as claimed in claim 13 wherein the step of utilizing the registered images in a third view comprises alternately overlaying the first and second registered images in the third view to indicate the amount of mismatch between the pair of images.
16. The computer program product as claimed in claim 13 wherein the step of utilizing the registered images in a third view comprises presenting the first and second registered images side by side in the third view synchronized in terms of zoom level, image center, and cursor position, whereby a position of a first cursor on a point of interest in the first image automatically positions a second cursor over the corresponding point of interest in the second image.
17. The computer program product as claimed in claim 13 wherein the step of registering the first and second images comprises producing a polynomial correlation between the refined reference points of the two images and warping the two images until two registered images are obtained.
18. The computer program product as claimed in claim 13 wherein the program is provided over a network to the user.
19. A system for placing and confirming reference points associated with image registration for a radiographic image processing application, wherein the reference points identify similar image positions in separate first and second radiographic images representing substantially the same object taken at different times, said system comprising:
a placement processing stage for presenting a “zoomed out” view of the full extent of the first and second radiographic images side by side in a first graphical user interface view in order to allow a user to place potential reference points in their approximate locations on each image, all the while maintaining context for the user;
a refinement processing stage for presenting a “zoomed in” view of an area of the first and second images around each of the potential tie points in a second graphical user interface view to allow the user to refine the placement of the potential reference points, thereby enabling the generation of refined reference points suitable for registration;
a correlation and registration processing stage for registering the first and second images by utilizing the refined reference points, thereby producing first and second registered images; and
a registration review processing stage for utilizing the registered images in a third graphical user interface view to indicate the amount of mismatch between the first and second images.
20. The system as claimed in claim 19 wherein the placement processing stage constrains the user to locate a corresponding point in the second image after locating a point in the first image.
21. The system as claimed in claim 19 wherein the registration review processing stage alternately overlays the first and second registered images in the third view to indicate the amount of mismatch between the pair of images.
22. The system as claimed in claim 19 wherein the registration review processing stage presents the first and second registered images side by side in the third view synchronized in terms of zoom level, image center, and cursor position, whereby a position of a first cursor on a point of interest in the first image automatically positions a second cursor over the corresponding point of interest in the second image.
23. The system as claimed in claim 19 wherein the correlation and registration processing stage produces a polynomial correlation between the refined reference points of the two images and warps the two images until two registered images are obtained.