Distorted image correction apparatus and method

• US 9,569,824 B2
• Filed: 04/18/2013
• Issued: 02/14/2017
• Est. Priority Date: 03/27/2013
• Status: Active Grant

• Current Assignee: NextChip Co., Ltd.
• Original Assignee: NextChip Co., Ltd.
• Inventors: Jang, Won Jun, Kim, Hyun Soo, Song, Ho Hyon
• Primary Examiner(s): Wu, Jingge
• Application Number:
  US14/779,585
• Publication Number:
  US 20160055629A1
• Time in Patent Office: 1,398 Days
• US Class Current: 1/1
• CPC Class Codes: G02B 13/0005 having F-Theta characteristic scanning systems employing movable or deformable optical elements G02B26/10
• CPC Class Codes: G06T 2207/10004 Still image; Photographic image
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/30252 Vehicle exterior; Vicinity of vehicle
• CPC Class Codes: G06T 2210/44 Morphing
• CPC Class Codes: G06T 5/80 Geometric correction

Abstract

With regard to a distortion correction apparatus and method which are applicable to hardware for real-time distortion correction, provided are a distorted image correction apparatus and method for correcting a distortion of an image by using a non-polynomial estimation function suitable for a hardware operation, and for correcting the distortion of the image by utilizing a morphing form.

Claims

1. An apparatus for correcting a distorted image, which is applicable to hardware for real-time distortion correction, the apparatus comprising:

at least one processor; and

a memory having instructions stored thereon executed by the at least one processor to perform;

receiving a distorted image through a fisheye lens;

configuring an image output signal for the distorted image;

estimating an image coordinate of a corrected image based on the distorted image;

estimating an image brightness of the distorted image based on the estimated image coordinated;

correcting the distorted image by synchronizing the estimated image brightness with the image output signal; and

performing morphing to final distortion correction through adjustment of a focal distance coefficient to generate a final corrected image.

2. The apparatus of claim 1, wherein the estimating the image coordinate estimates the image coordinate based on Equation 1,

r_d=α

×

arctan(r_u×

f) 

 

[Equation 1]

wherein “

r_u”

denotes a distance from a center of the corrected image to the image coordinate, “

r_d”

denotes a distance from a center of the distorted image to the image coordinate, “

f”

denotes a focal distance of the fisheye lens, and “

α

”

corresponds to each degree of correction of the distorted image.

3. The apparatus of claim 1, wherein the performing morphing comprises correcting the corrected image by sequentially changing a distortion correction coefficient from an initially set distortion correction coefficient to a finally set distortion correction coefficient.

4. A method of correcting a distorted image, which is applicable to hardware for real-time correction of a distortion, the method comprising:

receiving a distorted image through a fisheye lens;

configuring an image output signal for the distorted image;

estimating an image coordinate of a corrected image based on the distorted image;

estimating an image brightness of the distorted image based on the estimated image coordinate;

correcting the distorted image by synchronizing the estimated image brightness with the image output signal, and

performing morphing to final distortion correction through adjustment of a focal distance coefficient to generate a final corrected image.

5. The method of claim 4, wherein the estimating the image coordinate estimates the image coordinate based on Equation 2,

r_d=α

×

arctan(r_u×

f) 

 

[Equation 2]

wherein “

r_u”

denotes a distance from a center of the corrected image to the image coordinate, “

r_d”

denotes a distance from a center of the distorted image to the image coordinate, “

f”

denotes a focal distance of the fisheye lens, and “

α

”

corresponds to each degree of correction of the distorted image.

6. The method of claim 4, wherein the correcting the distorted image comprises:

detecting a trigonometric function based on the image coordinate;

estimating a first distance, which is a distance from a center of the corrected image to the image coordinate by multiplying the image coordinate and the trigonometric function;

detecting an arctangent value by multiplying the first distance and a focal distance of the fisheye lens; and

estimating a second distance, which is a distance from a center of the distorted image to the image coordinate, by multiplying the arctangent value and the correction coefficient.

7. A non-transitory computer-readable storage medium storing a program for causing a processor to perform the method of claim 4.