Maybe this software is interesting for some people here (I’m not sure):
Quote from the AwesomeBump website:
AwesomeBump 4.0 is a free and open source program designed to generate normal, height, specular or ambient occlusion, roughness and metallic textures from a single image. Since the image processing is done in 99% on GPU the program runs very fast and all the parameters can be changed in real time. AB was made to be a new alternative to known gimp plugin called Insane Bump. Since version 3.0 AB is supporting PBR shading model which makes this software more Awesome! Since 4.0 Grunge maps are available.
AwesomeBump is totaly written in Qt thus you don’t need to install any aditionall libraries. Just download and install Qt SDK, download the project from the repository, build and run. It will work (or should) on any platform supported by Qt.
The website:
http://awesomebump.besaba.com/
On GitHub:
Also information about AwesomeBump here:
https://blenderartists.org/forum/showthread.php?364529-AwesomeBump-A-free-alternative-to-CrazyBump and
https://blenderartists.org/forum/showthread.php?366395-AwesomeBump-3-0-beta-released
Latest is AwesomeBump 5.0