The HDR module is based on the image fusion technique which considers the edge response, the “well exposed” measure and the “well saturated” measure. The fusion works locally. That means the measures of quality are computed for every single pixel from its neighborhood over the whole picture stack. If we simplify the fusion process, we can say that pixels with the same coordinates are compared throughout the stack of images and the one with the highest quality measure is chosen to be used in the resulting image.