enblend 4.0+dfsg-6ubuntu3 (amd64 binary) in ubuntu trusty

 Enblend is a tool for compositing images. Given a set of images that overlap
 in some irregular way, Enblend overlays them in such a way that the seam
 between the images is invisible, or at least very difficult to see. It can,
 for example, be used to blend a panorama composed of several images.
 .
 It uses a Burt & Adelson multi-resolution spline. This technique tries to
 make the seams between the input images invisible. The basic idea is that
 image features should be blended across a transition zone proportional in
 size to the spatial frequency of the features. For example, objects like
 trees and windowpanes have rapid changes in color. By blending these
 features in a narrow zone, you will not be able to see the seam because the
 eye already expects to see color changes at the edge of these features.
 Clouds and sky are the opposite. These features have to be blended across a
 wide transition zone because any sudden change in color will be immediately
 noticeable.
 .
 Enblend does not align images for you. Use a tool like Hugin or PanoTools to
 do this. The TIFFs produced by these programs are exactly what Enblend is
 designed to work with.