It sometimes arise that I need to use, for an article, a book chapter or any other written work, figures that I have already published (not figures published by others). These are usually schematic figures explaining what a chemical or physical system look like, how an algorithm works, etc. Thus, instead of reusing the exact same figure, I can easily create another one, conveying the same message with (more or less subtle) differences in presentation.
However, I have no idea how to answer the following question: how different need two figures be to avoid the second one infringing on the copyright of the first? What is a good rule of thumb to be used? Is it enough to change one of the following:
- color scheme
- viewpoint of a 3D visualization
- moving around blocks in a 2D diagram (or mind map)
- changing axis properties (labels, tick mark positions, etc.) in a graph