Weng Jiawen, Zhou Weishuai, Ma Simin, Qi Pan, Zhong Jingang
Department of Applied Physics, South China Agricultural University, Guangzhou 510642, China.
Department of Optoelectronic Engineering, Jinan University, Guangzhou 510632, China.
Sensors (Basel). 2020 Dec 31;21(1):209. doi: 10.3390/s21010209.
The existing lens correction methods deal with the distortion correction by one or more specific image distortion models. However, distortion determination may fail when an unsuitable model is used. So, methods based on the distortion model would have some drawbacks. A model-free lens distortion correction based on the phase analysis of fringe-patterns is proposed in this paper. Firstly, the mathematical relationship of the distortion displacement and the modulated phase of the sinusoidal fringe-pattern are established in theory. By the phase demodulation analysis of the fringe-pattern, the distortion displacement map can be determined point by point for the whole distorted image. So, the image correction is achieved according to the distortion displacement map by a model-free approach. Furthermore, the distortion center, which is important in obtaining an optimal result, is measured by the instantaneous frequency distribution according to the character of distortion automatically. Numerical simulation and experiments performed by a wide-angle lens are carried out to validate the method.
现有的镜头校正方法通过一个或多个特定的图像失真模型来处理失真校正。然而，当使用不合适的模型时，失真确定可能会失败。因此，基于失真模型的方法会有一些缺点。本文提出了一种基于条纹图案相位分析的无模型镜头失真校正方法。首先，从理论上建立了失真位移与正弦条纹图案调制相位之间的数学关系。通过对条纹图案的相位解调分析，可以逐点确定整个失真图像的失真位移图。因此，通过无模型方法根据失真位移图实现图像校正。此外，根据失真的特性，通过瞬时频率分布自动测量在获得最佳结果中很重要的失真中心。进行了数值模拟和由广角镜头进行的实验来验证该方法。
