How to create a signature with transparency in Photoshop?

Question

Design

I wrote my signature on a square sticker and scanned it.
How to make halftones and partially colored paper bumps be converted to translucent tones.
If it is known that the color of the ink pen is blue, and the canvas is white with a light gray relief.
UPD: There is a similar function when I choose OVERLAY MODE for a layer, but it only works for existing backgrounds, and does not work for a transparent background. Maybe some kind of mask to impose or something else?
UPD2: as for example in a tablet for designers, where the pressure on the pen is taken into account, i.e. A light press draws a slightly shaded line, and if you press hard, the brightness increases.

Answer 1

Using levels or curves, bring the background to a pure uniform color (preferably white, burnt - with a normal scan quality, the signature itself will not suffer), then highlight the white color and delete it.