Bump map

To create the bump map I opened the texture in that I created in Photoshop and desaturated it.

Next I adjusted the levels to increase the contrast.

I used a high pass filter on the image and then used the clone stamp tool to blend the edges so that they did not create bumps around the seams on the model.

I applied the bump map material to the head model and rendered an image to see the effect. I found that the bump effect was too much so I changed the amount down from 30 to 1 and this was still too high so I created the bump map again using a lower setting for the high pass filter.

I applied a mix material to the model and applied noise material into he second slot. I set the type to fractal to create a skin like texture to create the pores on the model.

I zoomed into the head and rendered an image to see the bump map applied to the model. By adjusting the mix amount I could adjust how much of each of the two textures were blended together.

Later when creating the spec map I found that the bump map problem was caused by using a PSD file. I saved the image as a PNG and this worked better.