Removal of Uneven Illumination in Panorama Using Illumination Transfer

The composite images in a panorama may be captured in different light conditions, which leads to different colors of the same scene in consecutive images. The existing color smoothing methods only narrow the color difference in the connection of two images. The existing color correction methods fail when the illumination difference is large. So usually there are some seams or color blocks in the resulting panoramas. This paper proposes a new illumination correct and transfer method to keep the color consistency in a panorama. Firstly, it decomposes all the composite images into illumination and reflectance components based on the Retinex theory. Secondly, one of the above illumination components is selected as the ground truth illumination, and other illumination components are adjusted to the ground truth illumination based on a global illumination mapping model. Thirdly, all the adjusted illuminations are transferred back to the original images. Image stitching is performed with these adjusted images. Compared with the state of the art, the proposed method can generate consistent, nature illumination in panoramas without producing color blocks and residual seams, especially when the illumination difference is large.