Research On Tone Mapping For High Dynamic Range Image With Eage Preserving Minimization

High dynamic range image with rich detail,can be a good reproduction of brightness range for the natural scene,which has broad application prospects in satellite meteorology,military medical and other aspects.Although the devices with a high dynamic range display have appeared,they are not yet widely used because of its high price The dynamic range of common display devices is still so limited,in order to display HDR images on a display device,that tone mapping algorithms have been proposed.Tone mapping algorithms compress the brightness of HDR imaoe within the range of common display device,preserve image details,achieve satisfactorily visual efFects This paper analyzes the common HDR formats,introduces RGBE encoding method and several tone mapping algorithms.We consider the tone mapping as a variational problem.The compression essentially apply to the brightness of the image,and the optimal Solution of the variational problem is the brightness of the low dynamic range image what we want.Solving the problem,we use the guided filter with edge preserving and the principles of photographic methods to approximate the brightness of the low dynamic range images.Finally we obtain the optimal solution by iteration.The common tone mapping algorithms and the algorithm presented in this paper are analyzed,then we use DRIM(Dynamic Range Independent Metrics)to evaluate the images.This metric consists of three main parameters:loss of visible contrast,amplification of invisible contrast and reversal of visible contrast.Comparing the results of this paper with several classic tone mapping algorithm,we get good performance.