Recovering high dynamic range by Multi-Exposure Retinex

The matter of generating high dynamic range (HDR) image from a number of differently exposed pictures arises to satisfy the needs of high-quality imaging and industrial applications. A number of HDR image generation algorithms have been proposed in the past. However, the HDR radiance map recovered by these classical methods cannot completely exclude the noisy pixels in the input images and thus are unable to produce the optimal result with highest possible SNR. In this paper we are going to introduce a new HDR generation algorithm based on the Multi-Exposure Retinex model deduced in this paper for HDR image composition. The luminance component L and the reflectance R are synthesized independently before being combined together. A novel R image composition method is introduced to help the composed result image reach the highest possible SNR. The method is tested on grey-level images in this paper, but it can be easily extended to the color-image version.