Histogram Painting for Better Photomosaics

Histogram painting is a method for applying local histogram transformations to an image without introducing discontinuities at the boundary of the transformed region. Using interactive tools similar to those found in standard paint programs, the histogram from one part of an image can be “painted” onto another. This is useful for improving the results of seam elimination algorithms in photomosaicing applications. When local intensity distributions differ significantly at tile edges, a noticeable shift in appearance may remain even after the seam is removed. Histogram painting can be used to reduce these differences before removing the seam. The technique can also be used to remove shadows from an image by “painting” the histogram from lit regions onto the shadowed portions.