Wide-angle distortion correction by Hough transform and gradient estimation

Wide-angle cameras have been widely used in surveillance and endoscopic imaging. An automatic distortion correction method is very useful for these applications. Traditional methods extract corners or curved straight lines for estimating distortion parameters. Hough transform is a powerful tool to assess straightness. However, previous methods usually require some human intervention or only focus on using a single curve. In this paper, we propose a new method based on Hough transform by considering all curves into the estimation of distortion parameters. By considering the relationship between distortion parameters and curves, our method is fully automatic and does not require manual selection of curves in an image. Experiments on synthetic and real datasets have been conducted. The results of our method are also compared with other Hough Transform based methods in quantitative measures. The experimental results show that the accuracy of the proposed automatic method is comparable to those of other manual line-based methods.