Multi-image high dynamic range algorithm using a hybrid camera

This paper proposes a multi-image high dynamic range (HDR) algorithm using a hybrid camera, plus a tone mapping algorithm based on sub-band decomposed multi-scale retinex (SD-MSR). Conventional multi-image HDR algorithms, which produce a single HDR image from multiple low dynamic range (LDR) images, usually perform registration by exploiting homography derived from scale-invariant feature transform matching between adjacent images to overcome severe differences in luminance. However, such a registration can cause ghost artifacts, because motion information for moving objects can be inaccurate. In order to solve this problem, we employ a hybrid camera that simultaneously produces low-resolution (LR) video sequences and high-resolution (HR) still images. So, we can estimate accurate motion from the LR video because of homogeneous luminance. Then, we apply the estimated motion information to the registration between the corresponding HR images prior to HDR image synthesis. Finally, we present a tone mapping algorithm based on SD-MSR to enhance details in the synthesized HDR image. Experimental results show that the proposed algorithms outperform state-of-the-art HDR algorithms.