OpenSUSE :: Image Stacking Application To Do Macro Work

Is there a free image stacking application in Linux. I do a lot of macro work and I even use stacking for larger pieces of work as well. It allows me to create a better, larger DOF than you would normally get with a Macro lens, which tends to be shallow. If you have never heard of stacking images it is like stitching images together for a panorama image. Only this works by selecting the sharpest parts of the image. The images are stacked up on top of eachother, the software selects the sharpest parts of each image and the joins them all up making your object hopefully sharper. You need a tripod to do this work.