Distorted image correction apparatus and method
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.
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 .