I shot a bird in my backyard. As it flies from tree to tree it becomes difficult to see it because the background is only vegetation. I'd like to "enhance" the bird by making it "brighter" against the background, i.e. by turning the surrounding area "darker". For example, when a TV shots a police chase, the vehicle being followed becomes distinguished (or "brighter") from the others (that become "darker"). Is this possible in Kdenlive? What's the technical term that defines this effect?