Study on the effect of object to camera distance on polynomial expansion coefficients in barrel distortion correction

Videoendoscopy is becoming increasingly popular in surgical procedures. Wide-angle lenses are commonly employed in such applications for enhanced viewing capability. However, images captured with these lenses suffer from barrel distortion. 2D distortion correction for images captured with wide-angle lenses has been widely investigated. In clinical applications, it is necessary to incorporate correction techniques that are independent of the distance from the object to the camera lens. In this paper, we prove that for a wide-angle camera lens with fixed focal length, the distortion correction coefficients remain the same for distances within the minimum and maximum range (depth of field). Experiments have also been performed to verify this.