Non-dyadic fisheye lens correction model for image enhancement

Abstract

This paper presents a non-dyadic framework to improve example-based enhancement of radially distorted images acquired by a very wide-angle lens. In order to remove both jagging and blurring artifacts in the correction process of the fisheye lens' barrel distortion, the proposed method first performs non-dyadic or multiple-step geometric correction based on the parabolic equation-based lens distortion model. At each correction step, an example-based image enhancement method removes undesired geometric correction artifacts such as jagging and blurring. Experimental results demonstrate that the proposed method outperforms existing fisheye lens image enhancement methods in the sense of both subjective and objective measures. Based on both theoretical advancement and experimental results, the proposed method can be used for various wide-view imaging applications including vehicle front-and rear-view cameras and wide-angle video surveillance systems. (C) 2015 Optical Society of America