How to edit human skinning texture without loosing the original resolution?

Hi,
I have got a sample human model and skinning dress texture for him. Attached is the skinning dress texture image. I would like to how does this image created? Using which tool, we can create such human skinning textures and how can i edit further if i want to modify, without loosing the actual resolution. I tried modifying using Photoshop, but i lost the actual resolution. Could someone please suggest me?

Thank you!

Getsy.