An Improved Non-linear Masking Algorithm for HDRImage Tone Reproduction

Objective A new tone-reproduction algorithm for high-dynamic-range(HDR)images is proposed inthis paper.The image color appearance model is good at predicting color appearance of images,so thecalculation frame of the new algorithm is based on the latest image color appearance model iCAM06.The tone-compression function of iCAM06was improved significantly.The Hyperbola tone-compres-sion function of iCAM06was replaced by the tone-compression function based on the improved non-linear masking,and the new tone-compression function was used for tone-compression of the base lay-er image.In addition,in the rendering process of the HDR images,the new algorithm introduced the“Hunt effect”and“Stevens effect”predicting model proposed previously.Finally,the subjective eval-uation test and DRI model were used to evaluate preference and scene-reproduction accuracy of thenew algorithm respectively.The result of the evaluation test shows that the new algorithm has a verygood effect on preference and scene-reproduction accuracy.