I have an image. I want to superimpose a drawing (hopefully make it transparent in parts not of the drawing) and be able to scale it, rotate it and translate it visually (not programmatically) until I find it that they match satisfactorily.
What tools (hopefully open source) I can use to do this?
I have available a Linux and a Windows machine, so no problem with the operating systems.
You should be able to accomplish this with GIMP, a Windows and Linux program. Import each image to its own layer.
Use the layer tools to reduce the opacity of the top layer. Ensure that changes to be made will apply only to the selected layer, not to "all layers."
The transparency/reduced opacity will provide you with the necessary reference to accomplish your goal.
This can be done in non-free programs. I bought and use Corel Paint Shop Pro and have done exactly what you require. Almost certainly Adobe Photoshop is capable as well as others.
