Step 1, open the image and duplicate 3 layers.
Step 2, change layer 1 to black and white.
Step 3, increase the contrast. The parameters are as shown in the figure:
Step 4, use Filter – Blur – Special Blur. The parameters are as shown in the figure:
Step 5, use Filter – Blur – Gaussian Blur. The parameters are as shown in the figure:
Step 6, use Filter-Noise-Middle. The parameters are as shown in the figure:
Step 7, change layer 2 to black and white.
Step 8, increase the contrast. The parameters are as shown in the figure:
Step 9, use Filter – Stylize – Find Edges.
Step 10, use curves to remove the gray parts of the picture. The parameters are as shown in the figure:
