Infrared imaging detection and positioning method for underground building in planar land surface environment

Patent metadata

Field	Value
Publication number	US-9741120-B2
Application number	US-201415105456-A
Country	US
Kind code	B2
Filing date	Sep 2, 2014
Priority date	Dec 31, 2013
Publication date	Aug 22, 2017
Grant date	Aug 22, 2017

Abstract

An infrared imaging detection and positioning method for an underground building in a planar land surface environment comprises: obtaining an original infrared image g 0 formed after stratum modulation is performed on an underground building, and determining a local infrared image g of a general position of the underground building in the original infrared image g 0 ; setting an iteration termination condition, and setting an initial value h 0 of a Gaussian thermal diffusion function; using the local infrared image g as an initial target image f 0 , and performing iteration solution of a thermal expansion function h n and a target image f n by using a maximum likelihood estimation algorithm according to the initial value h 0 of the Gaussian thermal diffusion function; and determining whether the iteration termination condition is met, if the iteration termination condition is met, using the target image f n obtained by means of iteration solution this time as a final target image f; and if the iteration termination condition is not met, continuing to perform iteration calculation. In the method, by performing demodulation processing on the infrared image formed after stratum modulation is performed on the underground building, the display of the infrared image of the original underground building is clearer, and the real structure of the underground building can be inverted.

First claim

The invention claimed is:

1. An infrared imaging detection and positioning method for an underground building in a planar land surface environment, wherein the method performs, according to a Gaussian model for energy diffusion of an underground building, demodulation processing on an original infrared image formed after stratum modulation is performed on the underground building, to obtain a target image of the underground building; and the method comprises steps of:
(1) acquiring an original infrared image g 0 formed after stratum modulation is performed on an underground building, and determining a local infrared image g of a general position of the underground building in the original infrared image g 0 ;
(2) setting an iteration termination condition, and setting an initial value h 0 of a Gaussian thermal diffusion function;
(3) using the local infrared image g as an initial target image f 0 , and performing iteration solution of a thermal expansion function h n and a target image f n by using a maximum likelihood estimation algorithm according to the initial value h 0 of the Gaussian thermal diffusion function; and
(4) determining whether the iteration termination condition is met, if the iteration termination condition is met, using the target image f n obtained by means of iteration solution this time as a final target image f, and if the iteration termination condition is not met, returning to step (3) to continue to perform iteration calculation.

2. The method of claim 1 , wherein step (1) is specifically:
(1.1) dividing the original infrared image g 0 into N infrared image areas having a size of m×m pixels;
(1.2) calculating average gray values of the N infrared image areas, wherein an average gray value of the i th infrared image area is:

G
i

=

1

m
×
m

⁢

∑

j
=
1

m
×
m

⁢

g
ij

,

i=1□N, and g ij is a gray value of the j th pixel in the i th infrared image area;
(1.3) separately calculating a difference between average gray values of adjacent infrared image areas: □G=G i+1 −G i ; and
(1.4) using an area having a large average gray value and a small difference □G with an average gray value of an adjacent area as the local infrared image g that needs demodulation processing.

3. The method of claim 1 , wherein in the iteration solution of the thermal expansion function h n and the target image f n in step (3), iteration calculation is specifically performed according to the following two formulas:

h

n
+
1

⁡

(

x
,
y

)

=

{

[

g
⁡

(

i
,
j

)

h
n

⁡

(

x
,
y

)

*

f
n

⁡

(

i
,
j

)

]

*

f
n

⁡

(

-
i

,

-
j

)

}

*

h
n

⁡

(

x
,
y

)

f

n
-
1

⁡

(

i
,
j

)

=

{

[

g
⁡

(

i
,
j

)

h

n

Assignees

• Univ Huazhong Science Tech

Inventors

• Zhang Tianxu
• Hao Longwei
• Lu Cen
• Ma Wenxuan
• Wang Yuehuan
• Sang Nong
• Yang Weidong

Classifications

• G06T7/70 Primary

  Determining position or orientation of objects or cameras (camera calibration G06T7/80) · CPC title

• G06T2207/20076

  Probabilistic image processing · CPC title

• G06T2207/10048

  Infrared image · CPC title

• G06T5/001

  Physics · mapped topic

• G01J5/10

  using electric radiation detectors · CPC title