Measurement method, and terminal

Patent metadata

Field	Value
Publication number	US-10552971-B2
Application number	US-201515561287-A
Country	US
Kind code	B2
Filing date	May 15, 2015
Priority date	May 15, 2015
Publication date	Feb 4, 2020
Grant date	Feb 4, 2020

Abstract

A method can measure the size of an object using a terminal having two cameras. The method includes obtaining, by a terminal using a first camera, a first image that includes a to-be-measured object, and obtaining, using a second camera, a second image that includes the to-be-measured object, where the first camera and the second camera are disposed in a same plane. The method also includes comparing locations of the to-be-measured object in the first image and in the second image, so as to obtain a total location offset of the to-be-measured object. Additionally, the method includes receiving a measurement point selection instruction entered by a user based on the first image, and calculating a distance between selected measurement points according to the total location offset, a distance between a center of the first camera and a center of the second camera, and a focal length of the first camera.

First claim

What is claimed is:

1. A method, comprising:
obtaining, by a terminal using a first camera, a first image that comprises a to-be-measured object;
obtaining, by the terminal using a second camera, a second image that comprises the to-be-measured object, wherein the first camera and the second camera are disposed in a same plane;
receiving, by the terminal, a measurement point selection instruction entered by a user based on the first image;
determining, by the terminal, selected measurement points in accordance with the measurement point selection instruction;
comparing, by the terminal, a first location of the to-be-measured object in the first image and a second location of the to-be-measured object in the second image, to obtain a total location offset of the to-be-measured object, wherein the total location offset is determined based on a sum of a first location offset of the first location in the first image and a second location offset of the first location in the second image, the first location corresponding to one of the selected measurement points; and
calculating, by the terminal, a distance between the selected measurement points according to the total location offset, according to a distance between a center of the first camera and a center of the second camera, and according to a focal length of the first camera.

2. The method according to claim 1 , wherein the method further comprises:
compressing imaging data of the first image and the total location offset as an image file;
storing the imaging data of the first image and the total location offset that are compressed as the image file, after comparing the first location of the to-be-measured object in the first image and the second location of the to-be-measured object in the second image;
parsing the image file, to obtain the imaging data of the first image and the total location offset; and
decoding the imaging data, to display the first image on a screen of the terminal, before receiving the measurement point selection instruction.

3. The method according to claim 1 , wherein the method further comprises:
displaying, on a screen of the terminal, a distance result obtained by calculation, after calculating the distance between the selected measurement points.

4. The method according to claim 1 , wherein the method further comprises:
notifying, by voice, the user, of a distance result obtained by calculation, after calculating the distance between the selected measurement points.

5. The method according to claim 1 , wherein comparing the first location of the to-be-measured object in the first image and the second location of the to-be-measured object in the second image is performed using the formula:
D=X 1 +X 2 ,
wherein D is the total location offset of the to-be-measured object, X 1 is the first location offset, and X 2 is the second location offset.

6. The method according to claim 1 , wherein calculating the distance between the selected measurement points is performed using the formula:

L
=

D
1

*

(

X
p

D
p

-

X
q

D
q

)

2

+

(

Y
p

D
p

-

Y
q

D
q

)

2

+

(

H
1

D
p

-

H
1

D
q

)

2

,

wherein L is the distance between the selected measurement points, (X p , Y p ) are coordinates of a measurement point p in the first image, D p is a total location offset of the measurement point p, (X q , Y q ) are coordinates of a measurement point q in the first image, D q is a total location offset of the measurement point q; and H 1 =h 1 /a, wherein h 1 is the focal length of the first camera and a is a size constant of a single pixel, wherein D 1 is the distance between the center of the first camera and the center of the second camera, and wherein one of the D p or D q is the total location offset.

7. The method according to claim 1 , wherein the method further comprises:
calculating a vertical distance from the to-be-measured object to a line connecting the center of the first camera and the center of the second camera by using the formula:
Z=H 1* D 1 /( X 1 +X 2 ),

wherein Z is the vertical distance from the to-be-measured object to the line connecting the center of the first camera and the center of the second camera, H 1 =h 1 /a, wherein h 1 is the focal length of the first camera and a is a size constant of a single pixel, D 1 is the distance between the center of the first camera and the center of the second camera, X 1 is the first location offset, and X 2 is the second location offset.

8. The method according to claim 1 , wherein the method comprises:
calculating a distance between two measurement points in response

Assignees

• Huawei Tech Co Ltd

Inventors

• Gu Xinggang
• Chen Shaojun
• Zheng Shisheng

Classifications

• G06T7/62

  of area, perimeter, diameter or volume · CPC title

• G06T2207/20101

  Interactive definition of point of interest, landmark or seed · CPC title

• G06T7/593 Primary

  from stereo images · CPC title

• G06T2207/10012

  Stereo images · CPC title

• G01B11/02 Primary

  for measuring length, width or thickness (G01B11/08 takes precedence) · CPC title