Modulation transfer function (MTF) evaluation in the imaging of the optical lenses with poorly corrected geometric distortion involves sampling region of interest (ROI) images that are affected by geometric distortion, reducing its accuracy. A based liquid-crystal-device MTF (LMTF) method is proposed for this purpose by evaluating MTF of the medical rigid endoscope. This method establishes a mathematical model of geometric distortion and analyzes two sampling ROI image manners in MTF evaluation. Compared with the distortion factor (DF) manner, the distortion correction manner relaxes the value of the DF to twice the maximum non-distortion value, extends the sampling ROI image to twice the size, reduces the average RRMSE value to 6%, and improves average accuracy on MTF by 1.2%. The experimental results provide good agreement with the theoretical prediction. Therefore, the proposed LMTF method can be referential for the other optical lenses with poorly corrected distortion.

中文翻译：

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基于 LCD 的畸变校正光学透镜调制传递函数评估方法

几何失真校正不佳的光学透镜成像中的调制传递函数 (MTF) 评估涉及对受几何失真影响的感兴趣区域 (ROI) 图像进行采样，从而降低其准确性。为此，通过评估医用硬性内窥镜的 MTF，提出了一种基于液晶器件的 MTF (LMTF) 方法。该方法建立了几何畸变的数学模型，并分析了MTF评估中的两种采样ROI图像方式。与失真因子（DF）方式相比，失真校正方式将DF的值放宽到最大非失真值的两倍，将采样的ROI图像扩展到两倍大小，将平均RRMSE值降低到6%，提高了MTF 的平均准确度提高了 1.2%。实验结果与理论预测非常吻合。因此，所提出的 LMTF 方法可以为其他畸变校正不佳的光学镜头提供参考。