图像像素坐标表示的镜头畸变模型

General lens distortion model expressed by image pixel coordinate

镜头畸变是影响测量精度的关键因素之一。非度量镜头畸变校正方法直接将图像物理坐标系下的镜头畸变模型应用于图像像素坐标系,忽略了非单位纵横比的情况。通过对成像过程进行分析,得到了更精确的像素坐标表示的镜头畸变模型,对现有的镜头畸变模型进行了修正,考虑了纵横比对镜头畸变的影响。通过实验,对新模型的可行性进行了验证,实验结果表明,新的模型能够有效地提高了测量精度。

Lens distortion is one of the key factors affecting measurement accuracy. Non metric lens distortion correc- tion methods usually utilize image physical coordinate expressed lens distortion models （physical-LDMs） to represent lens distortion in image pixel coordinate system, which neglects the case of non-unit aspect ratio. By analyzing the image formation process, image pixel coordinate expressed lens distortion models （pixel-LDMs） are derived, which are modifications to existing physical-LDMs. The case of non-unit aspect ratio is taken into account explicitly. In order to validate the proposed model, real image experiments are carried out. The experimental results show that the proposed model is feasible.