No free lunch: EditImage’s Matrix Transformations

There is no free lunch in life. It’s pretty much the same with image manipulation in Actionscript. There is no way around linear algebra. Well, the good news is that it’s linear by definition. The bad news is that it becomes a bit quirky in Actionscript. With the following links, I hope to answer some questions I regularly get asked for the EditImage component.

What you should know

An excellent starting point is Senocular’s introduction in transformation matrices. This should give you enough motivation to muddle through affine transformation and friends in vector calculations. Should you loose your patience while repeating or learning, go to the hands-on matrix transformation page of Adobe.

Once you are a champion in linear algebra and the matrix API of the Flash Player, you need to know that Adobe’s transformation matrix is the tranpose of the matrix that is usually used in math. Philip Kromer explains it on his blog. The same guy has also written a very usefull demo.