Hi @theweblady ! Welcome to forum!
Here are the steps after de-saturating and duplicating the layer:
- Choose duplicate layer and go to Filters - Edge Detect - Edge…:
- Algorithm: Sobel, Amount: (you have to try out how much fits best), Border behavior: black:
- Select Divide as blend mode for the layer:
- If the edges are too light or dark, use curves (Colors - Curves) to improve that:
- If the edges are very noisy, you can also de-noise them (Filter - Enhance - Noise Reduction):
I hope this helps.