High Dynamic Range Imaging Based on Cubic Spline Interpolation

Due to the limited quality of high dynamic range image which is restored by traditional calibration methods, this paper proposes a novel high dynamic imaging method to improve the quality of image. By cubic spline interpolation method, our algorithm converts the calibration of camera response function into solving a system of linear equations primarily. According to the variation of dynamic range, our algorithm makes an adjustment to the ratio of exposure manually in order to guarantee that the variation of the gray value is tending towards stability mostly. Afterwards, a recursive method is proposed to calculate the second-order derivative of each end point of spline function which is the essential condition of calibration. At last, the radiance of each pixel is recovered according to the reference point which is chosen previously and the result of calibration. Experiment results show that cubic spline interpolation is able to improve the local detail and global clarity. The proposed recursive method reduces the complexity of solving linear system of equations, so that real-time performance can be achieved.