earticle

영어

Every optical system is influenced with a set of aberrations. Some of them are corrected by the manufacturer of the optical system, other aberrations must be corrected additionally e.g. using methods of digital image correction. The presented paper describes a method which enables correction of a barrel or pillow distortion of an image of small range using the direct-mapping technique. The proposed method uses an algorithm of adaptive metaheuristics marked as jDE and a polynomial representation of the image distortion. The advantage of connecting direct mapping technique and adaptive metaheuristics is primarily high speed of finding basic coefficients of the correction polynomial; in our case it is polynomial of degree up to 7 and with a selectable combination of the used polynomial degrees. The disadvantage of the direct-mapping method is the necessity of reconstruction of the missing pixels in the final image, which is here solved very effectively by using optimizer jDE again. Using the proposed method it is possible to obtain high quality image free of barrel or pillow distortion. If the focus length of the used optical system is constant, values of the correction coefficients and positions of individual recovered pixels stay invariable as well