Just need help for making height maps from real world images. I use those maps with Blender making landscapes and other good stuff.
So can you help me? i put here images, first(Feuillee....) is source image.Second(mars_crater2.png) is example image from blender.

Perhaps you could make a canvas 50% grey and then with the image mode set to rgb simply go into quick mask mode and use the airbrush tool to to alter the selection and the go out of quick mask mode and use the airbrush with white or black forground color to gently airbrush the mask. Turning off the dancing ants can be useful. Do this by clicking [Ctrl + T].