03-19-2019, 07:51 AM
Best result are obtained by making the image monochrome, using only the Red channel: in the Channel mixer, set all three channels to 100% of the Red channel:
From that a bit of Levels, dragging both input handles inside to get full white (right handle) and full black (left handle), and using the middle handle to adjust readability:
From that a bit of Levels, dragging both input handles inside to get full white (right handle) and full black (left handle), and using the middle handle to adjust readability: