Distortion is an undesirable aberration found in optical imaging systems, necessitating numerical calibration. However, the fact that image distortion changes with observation distance can be used for ranging. This study developed a rapid, passive-ranging technique, which is simple, incurs low costs, results in minimal interference, and requires few parameters. After determining the location of reference points, the relationship between the normalized mean distortion of images and observation distance is described using two mathematical models, one of which is based on distortion theory and the other is derived from the curve fitting of the experimental results. Analyzing the instantaneous rate of image distortion can also assist in ranging. The proposed technique demonstrates high sensitivity at closer observation distances, but loses effectiveness as observation distances increase.
© 2014 Optical Society of America
Original Manuscript: December 3, 2013
Revised Manuscript: February 6, 2014
Manuscript Accepted: February 7, 2014
Published: March 19, 2014
Han-Chao Chang, Jyun-Yi Lai, Yi-Jui Chen, Yu-Hsuan Lin, Kuo-Cheng Huang, and J. Andrew Yeh, "Rapid ranging through evaluation of image distortion," Appl. Opt. 53, 1894-1902 (2014)