Method and device for operating CT-based three-dimensional image used for security inspection

Patent metadata

Field	Value
Publication number	US-10353110-B2
Application number	US-201515301060-A
Country	US
Kind code	B2
Filing date	Dec 16, 2015
Priority date	Dec 23, 2014
Publication date	Jul 16, 2019
Grant date	Jul 16, 2019

Abstract

The present disclosure provides a method and device for operating a CT-based three-dimensional image used for security inspection. The method includes: providing a CT-based three-dimensional image used for security inspection; accepting a selection of an image of an object in the three-dimensional image; and responding to the selection. The present disclosure has strong practicality, and can provide effective reference information for image judgment in the CT-based security inspection field.

First claim

What is claimed is:

1. A method for operating a CT-based three-dimensional image used for security inspection, comprising:
providing a CT-based three-dimensional image used for security inspection;
accepting a selection to select an image of an object in the three-dimensional image; and
responding to the selection;
wherein the providing the CT-based three-dimensional image used for security inspection comprises:
performing three-dimensional volume rendering on the CT-based image used for security inspection, and
obtaining position information of surfaces of the object in the three-dimensional image;

wherein the performing the three-dimensional volume rendering on the CT-based image used for security inspection comprises:
casting rays of light along a viewing direction,
performing volume texture sampling on the CT-based image used for security inspection according to the cast rays of light, and obtain color information, and
performing color combination and outputting a three-dimensional volume rendering result;

wherein the obtaining the position information of the surfaces of the object in the three-dimensional image comprises:
according to a preset transparency threshold, recording positions where the rays of light firstly hit opaque regions in the CT-based image used for security inspection as surface depths of the image of the object,
calculating gradient values of voxels at the positions as normal direction information of the positions, and
while outputting the three-dimensional volume rendering of the CT-based image used for security inspection, recording the surface depths and normal direction information of the image of the object in the three-dimensional image.

2. The method for operating a CT-based three-dimensional image used for security inspection according to claim 1 , wherein the accepting the selection to select the image of the object in the three-dimensional image, comprises:
accepting a selection to entirely select the image of the object in the three-dimensional image.

3. The method for operating a CT-based three-dimensional image used for security inspection according to claim 2 , wherein the accepting the selection to entirely select the image of the object in the three-dimensional image, comprises:
accepting a single-click selection or a frame selection on the image of the object in the three-dimensional image to entirely select the image of the object.

4. The method for operating a CT-based three-dimensional image used for security inspection according to claim 1 , wherein the accepting the selection to select the image of the object in the three-dimensional image, comprises:
accepting a local selection to locally select the image of the object in the three-dimensional image.

5. The method for operating a CT-based three-dimensional image used for security inspection according to claim 4 , wherein the accepting the local selection to locally select the image of the object in the three-dimensional image comprises:
accepting a double-click selection on the image of the object in the three-dimensional image to select a section of the image of the object; or
accepting a local frame selection on the image of the object in the three-dimensional image to select a local region of the image of the object.

6. The method for operating a CT-based three-dimensional image used for security inspection according to claim 2 , wherein the responding to the selection comprises;
displaying one or more of the following pieces of information: an image contour and a three-dimensional size of the image of the selected object, a density, an atomic number, a CT number and a substance state of the selected object, and information indicating whether the object is a hazardous object; and/or
if the object is a hazardous object, providing an alert or a notification.

7. The method for operating a CT-based three-dimensional image used for security inspection according to claim 4 , wherein the responding to the selection comprises:
displaying one or more the following pieces of information; a size of a local region of the image of the selected object, a density, an atomic number, a CT number and a substance state of the selected object, and information indicating whether the object is a hazardous object; and/or
if the object is the hazardous object, providing an alert or a notification.

8. The method for operating a CT-based three-dimensional image used for security inspection according to claim 1 , wherein the responding to the selection comprises:
obtaining size information of the selected part according to the surface depths and the normal direction information;
wherein the obtaining of the size information comprises:
calculating a variation value of a normal direction from a starting point to an ending point of the selected part; if the variation value is smaller than a preset angle threshold, querying the surface depths and converting the starting point and the ending point into three-dimensional coordinates, and outputting size measurement values in directions in which measurements are needed after coordinate conversion.

9. The method for operating a CT-based three-dimensional image used for security inspection according to claim 1 , wherein the responding to the selection comprises:
obtaining voxel collections for different objects in the CT-based three-dimensional image used for security inspection by dividing;
determining at least one selected object from the voxel collections for different objects based on different preset criteria; and
performing statistics on voxel information corresponding to the at least one selected object, and outputting size measurements of the object in a three-dimensional space.

10. A device for operating a CT-based three-dimensional image used for security inspection, comprising:
a processor; and
a memory for storing instructions executable by the processor;
wherein the processor is configured to:
provide a CT-based three-dimensional image used for security inspection;
accept a selection to select an image of an object in the three-dimensional image; and
respond to the selection:
wherein the providing the CT-based three-dimensional image used for security inspection comprises:
performing three-dimensional volume rendering on the CT-based image used for security inspection, and
obtaining position information of surfaces of the object in the three-dimensional image;

wherein the performing the three-dimensional volume rendering on the CT-based image used for security inspection comprises:
casting rays of light along a viewing direction,
performing a volume texture sampling on the CT-based image used for security inspection according to the cast rays of light, and obtain color information, and
performing color combination and outputting a three-dimensional volume rendering result;

wherein the obtaining the position information of the surfaces of the object in the three-dimensional image comprises:
according to a preset transparency threshold, recording positions where the rays of light firstly hit opaque regions in the CT-based image used for security inspection as surface depths of the image of the object,
calculating gradient values of voxels at the positions as normal direction information of the positions, and
while outputting the three-dimensional volume rendering of the CT-based image used for security inspection, recording the surface depths and normal direction information of the image of the object in the three-dimensional image.

11. The device according to claim 10 , wherein the processor is configured to accept a selection to entirely select the image of the object in the three-dimensional ima

Assignees

• Univ Tsinghua
• Nuctech Co Ltd

Inventors

• Zhang Li
• Wang Shuo
• Sun Yunda
• Huang Qingping

Classifications

• G06T2207/10072

  Tomographic images · CPC title

• G06T7/40

  Analysis of texture (depth or shape recovery from texture G06T7/529) · CPC title

• G01N23/046

  using tomography, e.g. computed tomography [CT] · CPC title

• G06T7/0002

  Inspection of images, e.g. flaw detection · CPC title

• G06T7/90

  Determination of colour characteristics · CPC title