METHOD FOR RECONSTRUCTING A 2D IMAGE FROM A PLURALITY OF X-RAY IMAGES

• US 20190325617A1
• Filed: 11/25/2016
• Published: 10/24/2019
• Est. Priority Date: 11/25/2016
• Status: Active Grant

• Current Assignee: Teledyne Dalsa Incorporated (Teledyne Technologies Incorporated)
• Original Assignee: Teledyne Dalsa Incorporated (Teledyne Technologies Incorporated)
• Inventors: Kessener, Yves, Lomako, Andriy, Miller, Joseph
• Granted Patent: US 11,195,309 B2
• Time in Patent Office: Days
• CPC Class Codes: G06T 11/005 Specific pre-processing for tomographic reconstruction, e.g. calibration, source positioning, rebinning, scatter correction, retrospective gating
• CPC Class Codes: G06T 2200/08 involving all processing steps from image acquisition to 3D model generation
• CPC Class Codes: G06T 2207/10116 X-ray image
• CPC Class Codes: G06T 2207/20221 Image fusion; Image merging
• CPC Class Codes: G06T 2207/30008 Bone
• CPC Class Codes: G06T 2207/30036 Dental; Teeth
• CPC Class Codes: G06T 2211/408 Dual energy
• CPC Class Codes: G06T 5/50 using two or more images, e.g. averaging or subtraction
• CPC Class Codes: G06T 5/73 Deblurring; Sharpening

Abstract

The present invention relates to a method and a system for producing X-ray images from an object. According to this invention, a shift-and-add method is used for generating a stack of linear tomography planes each associated with a different area inside the object. A set of shift values is defined from the consideration of ensuring that said stack of linear tomography planes fills in the tomographic volume with a spatial density adequate to the application. If so required by the application, some focal planes can be selectively processed for sharpness reduction in some areas to control the depth-of-field. A focus stacking method is used to synthesize a single 2D X-ray image from UPI the tomographic stack of images. A depth map of in-focus areas from the linear tomography stack can be used for creating a 3D object model.

Claims

6. The method according to claim 1, further comprising equaling a size of the focal planes at least in a direction where a shift of the underlying X-ray images has been applied during the shift-and-add method.

7. The method according to claim 1, further comprising storing the plurality of X-ray images from the X-ray detector in computer memory prior to performing the shift-and-add method or the focus stacking method.

8. The method according to claim 1, further comprising using a depth map of respective areas that are in sharpness in respective focal planes for constructing a 3D model of the object.

9. The method according to claim 1, wherein the shift-and-add method or the focus stacking method is performed in real-time using a Graphic Processing Unit.

10. The method according to claim 1, further comprising selective image processing of some areas of the focal planes before performing the focus stacking method, to control a depth-of-field (DOF) in the generated 2D image.

11. The method according to claim 10, wherein the selective image processing of some areas of the focal planes before performing the focus stacking method comprises blurring areas that do not correspond to a region of interest of the object.

12. The method according to claim 1, further comprising associating a set of shift values to X-ray images among the plurality of X-ray images, shifting the individual X-ray images by their associated shift value, and adding the plurality of X-ray images after performing said shifting.

13. The method according to claim 12, further comprising selecting the set of shift values for the shift-and-add method to achieve a non-uniform spatial density of the plurality of generated focal planes.

14. The method according to claim 1, wherein the plurality of X-ray images have been obtained using an X-ray source that emits X-rays having an X-ray energy distribution that alternates between two or more different distributions, wherein the plurality of X-ray images comprises a plurality of subsets of X-ray images, each subset of X-ray images corresponding to one particular X-ray energy distribution, the method further comprising performing the shift-and-add method and the focus stacking method for each subset of X-ray images separately to generate a respective 2D image.

15. The method according to claim 14, further comprising generating a single 2D image from the respective 2D images.

16. An X-ray system, comprising:

an X-ray source;

an X-ray detector;

a moving unit for causing a relative movement between an object to be imaged and at least one of the X-ray detector and the X-ray source during a process of obtaining a plurality of X-ray images; and

an image processing unit configured to generate the 2D image from the plurality of X-ray images.

17. The X-ray system according to claim 16, further comprising a mounting frame, wherein the X-ray source and the X-ray detector have a fixed positional relationship, wherein the X-ray system is configured to, using the moving unit, move the object relative to the X-ray source and X-ray detector, which are kept stationary relative to the mounting frame, or to move the X-ray source and the X-ray detector relative to the object, which is kept stationary relative to the mounting frame.

18. The X-ray system according to claim 16 or 17, further comprising a memory for storing the plurality of X-ray images from the X-ray detector prior to performing the shift-and-add method and/or the focus stacking method.

19. (canceled)