Image processing of images that include marker images

Patent metadata

Field	Value
Publication number	US-9324152-B2
Application number	US-201514851313-A
Country	US
Kind code	B2
Filing date	Sep 11, 2015
Priority date	Mar 15, 2013
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

A method, includes: obtaining an image, the image having marker images and a background image; identifying presence of an object in the background image using a processor; and providing a signal for stopping a procedure if the presence of the object is identified. An image processing apparatus, includes: a processor configured for: obtaining an image, the image having marker images and a background image; identifying presence of an object in the background image; and providing a signal for stopping a procedure if the presence of the object is identified. A computer product having a non-transitory medium storing instructions, an execution of which causes an image processing method to be performed, the method includes: obtaining an image, the image having marker images and a background image; identifying presence of an object in the background image; and providing a signal for stopping a procedure if the presence of the object is identified.

First claim

The invention claimed is:

1. An image processing method performed during a medical procedure, comprising:
obtaining an image, wherein the image is generated using a camera, the image having marker images of markers and a background image, the markers being for determining a position associated with a patient;
identifying presence of an object in the background image using a processor; and
providing a signal for stopping the medical procedure if the presence of the object is identified, so that the object is prevented from being mistakenly used as a marker for determining the position;
wherein the method further comprises setting a plurality of foreground pixels in the image that are to be excluded from detection to have a certain grayscale; and
wherein the act of providing the signal is performed using the processor.

2. The method of claim 1 , wherein the act of identifying the presence of the object in the background comprises:
dividing the image into a plurality of image portions arranged in a matrix; and
determines a mean or median value of pixel values in each of the image portions.

3. The method of claim 2 , wherein the act of identifying the presence of the object in the background further comprises determining a histogram using the determined mean or median values.

4. The method of claim 3 , wherein the act of identifying the presence of the object further comprises determining if any of the mean or median values exceeds a peak value of the histogram by more than a specified threshold.

5. The method of claim 2 , further comprising setting a size for one or more of the image portions.

6. The method of claim 5 , wherein the size is set manually.

7. The method of claim 5 , wherein the size is set automatically using the processor.

8. The method of claim 1 , further comprising flattening the image in greyscale so that gradient variation across the image is reduced.

9. The method of claim 8 , wherein the act of flattening the image in greyscale comprises:
sampling a set of points in the image;
generating an uniform gradient image with uniform grayscale gradient which is the best-fit to the sampled set of points; and
subtracting the uniform gradient image from the received image to generate an output image.

10. The method of claim 1 , further comprising excluding the object as a marker.

11. The method of claim 1 , wherein the act of receiving an image comprises receiving a sequence of images that includes the image, and the act of identifying the presence of the object is performed on a subset of the sequence of images.

12. An image processing apparatus for use in a medical procedure, comprising:
a processor configured for:
obtaining an image, wherein the image is generated using a camera, the image having marker images of markers and a background image, the markers being for determining a position associated with a patient;
identifying presence of an object in the background image; and
providing a signal for stopping the medical procedure if the presence of the object is identified, so that the object is prevented from being mistakenly used as a marker for determining the position;
wherein the processor is further configured for setting a plurality of foreground pixels in the image that are to be excluded from detection to have a certain grayscale.

13. The apparatus of claim 12 , wherein the processor is configured for:
dividing the image into a plurality of image portions arranged in a matrix; and
determines a mean or median value of pixel values in each of the image portions.

14. The apparatus of claim 13 , wherein the processor is configured for determining a histogram using the determined mean or median values.

15. The apparatus of claim 14 , wherein the processor is configured for determining if any of the mean or median values exceeds a peak value of the histogram by more than a specified threshold.

16. The apparatus of claim 13 , wherein the processor is configured to obtain a size for one or more of the image portions.

17. The apparatus of claim 16 , wherein the processor is configured to obtain the size by receiving an input from a user that represents the size.

18. The apparatus of claim 16 , wherein the processor is configured to obtain the size by determining the size using an algorithm.

19. The apparatus of claim 12 , wherein the processor is further configured for flattening the image in greyscale so that gradient variation across the image is reduced.

20. The apparatus of claim 19 , wherein the processor is configured to perform the act of flattening the image in greyscale by:
sampling a set of points in the image;
generating an uniform gradient image with uniform grayscale gradient which is the best-fit to the sampled set of points; and
subtracting the uniform gradient image from the received image to generate an output image.

21. The apparatus of claim 12 , wherein the processor is further configured to exclude the object as a marker.

22. The apparatus of claim 12 , wherein the processor is configured to receive a sequence of images that includes the image, and the processor is configured to perform the act of identifying the presence of the object on a subset of the sequence of images.

23. A computer product having a non-transitory medium storing a set of instructions, an execution of which causes an image processing method to be performed during a medical procedure, the method comprising:
receiving an image, wherein the image is generated using a camera, the image having marker images of markers and a background image, the markers being for determining a position associated with a patient;
identifying presence of an object in the background image; and
providing a signal for stopping the medical procedure if the presence of the object is identified, so that the object is prevented from being mistakenly used as a marker for determining the position;
wherein the method further comprises setting a plurality of foreground pixels in the image that are to be excluded from detection to have a certain grayscale.

Assignees

• Varian Med Sys Inc

Inventors

• Mostafavi Hassan
• Jeung Andrew

Classifications

• A61N5/1049 Primary

  for verifying the position of the patient with respect to the radiation beam · CPC title

• G06T2207/30204

  Marker · CPC title

• G06T2207/10116

  X-ray image · CPC title

• G06T7/0012

  Biomedical image inspection · CPC title

• G06T2207/30096

  Tumor; Lesion · CPC title