Transparent Scanning

[sen1h]

Hi, I got a hand drawing scans on tracing paper in PNG format, but background isn't transparent. I tried so much different way like change blend modes, play with levels and curves, but I couldn't find a solution. When I use color range selection, I messed up drawing all details is gone because it's hand drawing. If there is a solution, I will be glad if you help.

[Mylenium]

Image --> Calculations and the channels palette are your friend. Simply generate a suitable layer mask this way and tweak it

Mylenium