A Fast Calibration Method of Camera Response Function for High Dynamic Range Image

A fast and effective method is presented to solve the problem of inefficiency in calibration algorithm for camera response function in synthesis of high dynamic range image.Firstly,according to the fact that the corresponding illuminances on scenes in imaging process among multi-exposure images are accordant,a new least-squares error function is proposed to reduce the dimensions of calibration equation.Gaussian weight function is used in accordance with noise distribution of images in different exposures to eliminate ambient noise in image process in excessive dark and light area with high efficiency to solve equations.Meanwhile,robust QR decomposition is put forward to accelerate the calculation of camera response function.At last,the look-up table method is adopted and Gaussian weight function is used to synthetize the illuminances on scences and tone mapping;the result image can be well expressed to obtained the detail information of dark and light area in entire scene.The sufficient experimental results on various scenes indicate that this method has smaller computational amount,higher speed than traditional method and has good precision as well.The proposed method can be used to accomplish rapid calibration of camera response function while subjective effect is good in the visualization image obtained by this method.And this method can be applied widely in portable camera equipments.