Direct high dynamic range imaging method using experiential optimal exposure criterion

In this paper, we propose a simple but efficient image fusion method to combine LDR image sequence directly. The fusion results can be shown on the conventional media without tone-mapping operation. The foundation of our method is an experiential optimal exposure criterion that optimal exposure will be occurred at dramatic alteration point in LDR image sequence. In our method, each pixel value curve of LDRIs is preprocessed by chord length parameterizaiton in RGB color space. Then initial image fusion mask can be determined according to the location of maximum on the parameter curve´s derivative. The final HDR image can be extracted by pixel-level weighted summation using final smoothed image fusion mask. The sufficient experimentations on various scenes indicate that the proposed method can synthesize considerable HDR images for conventional media, but is more efficient than traditional HDRI methods.