These are just some tests of image maps, and see how realistic they can be with a little displacement. My conclusion is that it's not really a good way, unless for certain types of soil maybe. The stones are masked by PF, so the (grey) edges make them sink into the image mapped ground. Not a good way, I know. This is not intended to make something beautiful

I was thinking something else regarding normal maps and bump/displacement maps. I used to make bumpmaps out of a greyed image map (Pixplant does that), but dark areas are sunk, even if they are relatively higher. So a normal map would work better in that respect as all color is kind of flattened and bumps are still visible. But a normal map is RGB, with presumably the green channel as Y information. So I thought to just use that channel for a grey scale (lores) image map for bump, as the X and Z information isn't really useful anyway. Off to experiment....