相机响应函数定标的正则化方法

Calibration of camera response function based on the regularization method

相机响应函数是真实场景辐射量与图像灰度值之间的映射关系,对相机响应函数的标定具有重要的研究价值。根据相机的成像原理给出了相机响应函数的数学模型,分析了最小二乘法标定相机响应函数存在的病态问题。为了获得稳定、精确的相机响应函数,提出了一种正则化方法对相机响应函数进行标定,该方法在索波列夫空间中设置不同的正则算子。通过实验分别论证索波列夫参数不同时相机响应函数的稳定性,确定了索伯列夫空间参数,应用L曲线法确定了正则化参数。验证结果表明,正则化方法能够显著提高相机响应函数标定的稳定性和精确性。

Camera response function is the mapping between the real scene radiation and the image gray value,and it is significant to the calibration of the camera response functions.According to the imaging principle of the camera,the mathematical model of the camera response function was given,and the ill-posed problem of the least squares method for the calibration of the camera response function was analyzed.To obtain a stable and accurate camera response function,a regularization method using the variable regular operators set in the Sobolev space was proposed to calibrate the camera response function.The stability of camera response function was demonstrated under different Sobolev operators.The regularization parameters were determined by the L curve method and verified by experiments.The results indicate that the regularization method can improve the stability and accuracy of the calibration of the camera response function significantly.