IMAGE CAPTURE DEVICE AND IMAGE PROCESSING METHOD

• US 20120242782A1
• Filed: 09/28/2011
• Published: 09/27/2012
• Est. Priority Date: 03/24/2011
• Status: Abandoned Application

• Current Assignee: Hon Hai Precision Industry Co., Ltd.
• Original Assignee: Hon Hai Precision Industry Co., Ltd.
• Inventors: HUANG, JYUN-HAO
• Application Number:
  US13/246,873
• Publication Number:
  US 20120242782A1
• Time in Patent Office: Days
• US Class Current: 348/36
• CPC Class Codes: G06T 3/12 Panospheric to cylindrical image transformations
• CPC Class Codes: H04N 23/63 by using electronic viewfinders
• CPC Class Codes: H04N 23/698 for achieving an enlarged field of view, e.g. panoramic image capture
• CPC Class Codes: H04N 23/81 for suppressing or minimising disturbance in the image signal generation
• CPC Class Codes: H04N 25/61 the noise originating only from the lens unit, e.g. flare, shading, vignetting or "cos4"

Abstract

A method for processing an image captured by a fisheye lens of an image capture device. The method obtains a point (Px, Py) from an object plane of the fisheye lens, calculates a first projection point (Fx*, Fy*, Fz*) of the obtained point (Px, Py) on a first image plane of a virtual lens, calculates a second projection point (Fx, Fy) of the point (Fx*, Fy*, Fz*) on a second image plane of the fisheye lens, and obtains transforming formulae between (Px, Py) and (Fx, Fy). The method further obtains a back-projection point for each point of the captured image on the object plane of the fisheye lens according to the transforming formulae, and creates an updated image of the specified scene from the back-projection points.

Claims

1. A method for processing an image captured by an image capture device comprising a fisheye lens, the method comprising:

obtaining an image of a specified scene captured by the fisheye lens of the image capture device;

obtaining a point (Px, Py) from an object plane of the fisheye lens;

calculating a first projection point (Fx*, Fy*, Fz*) of the obtained point (Px, Py) on a first image plane of a virtual lens outside the fisheye lens;

calculating a second projection point (Fx, Fy) of the point (Fx*, Fy*, Fz*) on a second image plane of the fisheye lens;

obtaining transforming formulae from the point (Px, Py) on the object plane of the fisheye lens to the point (Fx, Fy) on the second image plane of the fisheye lens;

obtaining a back-projection point for each point of the captured image on the object plane of the fisheye lens according to the transforming formulae; and

creating an updated image of the specified scene from the back-projection points, and displaying the updated image of the specified scene on a display screen of the image capture device.

2. The method according to claim 1, wherein the first projection point (Fx*, Fy*, Fz*) is calculated by following formulae:

h1=√

{square root over (Px²+Py²)} 

 

(1)

h2=√

{square root over (h1²+f₀²)} 

 

(2)

h3=f₀*sin(ω

)  

 

(3)

h4 =P_y*cos(ω

)  

 

(4)

h34=h3+h4  

 

(5)

3. The method according to claim 2, wherein the second projection point (Fx, Fy) is calculated by following formulae:

Δ

=F_z*+|C₁−

C₀| 

 

(12)

4. The method according to claim 1, wherein a central angle of the virtual lens is greater than 180 degrees.

5. The method according to claim 1, wherein the image capture device is a speed dome camera or a pan/tilt/zoom (PTZ) camera.

6. An image capture device, comprising:

a fisheye lens;

a display screen;

a storage device;

at least one processor; and

one or more modules that are stored in the storage device and are executed by the at least one processor, the one or more modules comprising instructions;

to obtain an image of a specified scene captured by the fisheye lens;

to obtain a point (Px, Py) from an object plane of the fisheye lens;

to calculate a first projection point (Fx*, Fy*, Fz*) of the obtained point (Px, Py) on a first image plane of a virtual lens outside the fisheye lens;

to calculate a second projection point (Fx, Fy) of the point (Fx*, Fy*, Fz*) on a second image plane of the fisheye lens, and obtain transforming formulae from the point (Px, Py) on the object plane of the fisheye lens to the point (Fx, Fy) on the second image plane of the fisheye lens; and

to obtain a back-projection point for each point of the captured image on the object plane of the fisheye lens according to the transforming formulae, and create an updated image of the specified scene from the back-projection points, and display the updated image of the specified scene on the display screen.

7. The image capture device according to claim 6, wherein the first projection point (Fx*, Fy*, Fz*) is calculated by following formulae:

h1=√

{square root over (Px²+Py²)} 

 

(1)

h2=√

{square root over (h1²+f₀²)} 

 

(2)

h3=f₀*sin(ω

)  

 

(3)

h4=P_y*cos(ω

)  

 

(4)

h34=h3+h4  

 

(5)

8. The image capture device according to claim 7, wherein the second projection point (Fx, Fy) is calculated by following formulae:

Δ

=F_z*+|C₁−

C₀| 

 

(12)

9. The image capture device according to claim 6, wherein a central angle of the virtual lens is greater than 180 degrees.

10. The image capture device according to claim 6, wherein the image capture device is a speed dome camera or a pan/tilt/zoom (PTZ) camera.

11. A non-transitory storage medium having stored thereon instructions that, when executed by a processor of an image capture device, causes the image capture device to perform a method for processing an image captured by the image capture device, the method comprising:

obtaining an image of a specified scene captured by a fisheye lens of the image capture device;

obtaining a point (Px, Py) from an object plane of the fisheye lens;

calculating a first projection point (Fx*, Fy*, Fz*) of the obtained point (Px, Py) on a first image plane of a virtual lens outside the fisheye lens;

calculating a second projection point (Fx, Fy) of the point (Fx*, Fy*, Fz*) on a second image plane of the fisheye lens;

obtaining transforming formulae from the point (Px, Py) on the object plane of the fisheye lens to the point (Fx, Fy) on the second image plane of the fisheye lens;

obtaining a back-projection point for each point of the captured image on the object plane of the fisheye lens according to the transforming formulae; and

creating an updated image of the specified scene from the back-projection points, and displaying the updated image of the specified scene on a display screen of the image capture device.

12. The non-transitory storage medium according to claim 11, wherein the first projection point (Fx*, Fy*, Fz*) is calculated by following formulae:

h1=√

{square root over (Px²+Py²)} 

 

(1)

h2=√

{square root over (h1²+f₀²)} 

 

(2)

h3=f_o*sin( ω

)  

 

(3)

h4=P_y*cos( ω

)  

 

(4)

h34=h3+h4  

 

(5)

13. The non-transitory storage medium according to claim 12, wherein the second projection point (Fx, Fy) is calculated by following formulae:

14. The non-transitory storage medium according to claim 11, wherein a central angle of the virtual lens is greater than 180 degrees.

15. The non-transitory storage medium according to claim 11, wherein the image capture device is a speed dome camera or a pan/tilt/zoom (PTZ) camera.

16. The non-transitory storage medium according to claim 11, wherein the medium is selected from the group consisting of a hard disk drive, a compact disc, a digital video disc, and a tape drive.