Research On Adaptive Tone Mapping Algorithms With Regionalization

High dynamic range image records the luminance information of the real world,contains abundant image hierarchy.High dynamic range image is widely used in film and television,traffic safety,financial fields because of its realistic lighting effects.The paper indicates that most of the existing methods using a single parameter for tone mapping,and cannot take account of details of the distribution in the multi-area and multi-scale.The singleness of the global algorithm is not applicable to the high dynamic range image with complex brightness and color information.The local algorithm analyzes the local features of pixels,but it is not fully realize the difference between the bright and dark regions in the high dynamic range images.As the conventional algorithms fails to take into account the effect of intensity of stimulation to the tong mapping,an adaptive regionalization tone mapping algorithm is presented in this paper,which uses global algorithm in local scope,and compresses the dynamic range while strengthening the local feature of the image.The human eye has not the same discrimination ability for different range of light information,based on the nonlinear characteristics of human visual system for perceived luminance change,this paper presents an adaptive algorithm to partition the human vision based,fully consider the different contrast regions of human eyes brightness perception ability.the image is divided into four regions by the psychology Web-Fechner law after enhanced by the logarithmic image processing model.Based on the partition result,a multi-scale logarithmic tone mapping approach using a set of parameter is applied to different ranges of image brightness,then the image is blended using the scale factor of each region.Experimental results demonstrate that the proposed algorithm can compress the dynamic range and keep the whole contrast of the image,while reproducing image detail clearly.Logarithmic tone mapping is widely used but it suffers from the limited range compression ability and the lost of details,this article proposed an adaptive tone mapping algorithm based on quantization techniques and partition.After extracting brightness information,three kinds of region are classified by two key value,which are related with the logarithmic of average of brightness image.Quantization technology and a nonuniform weight are also adopted to compress the dynamic range.To compensate details in tone mapped image,bilateral filter,this used to extract detail layer.Experimental results show that this algorithm can reproduce the real scene information and preserve more details.