Materialize - by Bounding Box Software Alternatives

AwesomeBump is an open source program designed to generate normal, height, specular or ambient occlusion 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.

This is a suite of ten Gimp plugins known as the 'Resynthesizer'. The most commonly used is 'Heal selection' but all use the plugin whose full interface is found at 'Filters>Map>Resynthesize.

ModLab is a free tool that can generate and fine tune normal maps in a realtime rendering environment.

Crazybump generates lighting maps from 2D textures. It supports ambient occlusion (AO) maps, bump maps, normal maps, and more.

Knald is the world’s first GPU powered solution for generating “bake quality” textures from any 2D source texture.

Converts a bitmap into a seamless PBR material, including normal, AO, roughness and metallic.