The Cage Transform-tool (which is an equivalent to Adobe Photoshop’s Free Transform tool) uses a polygone instead of a (normal) rectangle to transform parts of an image.

How does the tool work?

Open an image you want to deform

Choose the new Cage-Tool and place a polygone (like the paths tool) over the parts you want to transform

Close the polygone by hitting the first point. The tool then switchs to the transform mode

Move the points of the polygone and the below image is transformed accordingly.

Simple and just awesome ;)

Video & Information

The tool was developed last summer during Googles Summer of Code 2010 by Michael Muré who did an excellent job as it seems because the tool works very good and seems to be almost finished.

To see how this works we’ve just created a 1-minute video showing the tool in action ! (there is no audio in this video)

The tool is not found in the master branch of the current GIMP development, it has a seperate branch named soc-2010-cage-2. If you want to try it out you need to checkout this seperate branch. Hopefully it will make the way into 2.8 once it is released (I remember that there were some licence issues/problems for the green coordinates). The tool is now in the master branch of current GIMP development, so it will come with GIMP 2.8.

Enjoy the video, the new tool and big thanks to the author of the tool itself: Michael Muré !