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Apply Multiply transparency. Then make a PNG + Alpha bitmap.

You can also use Photo Tool > Select Colors to Enhance (top right of screen). Click on the white. Then right click and select Make...

True Color PNG and PDF.

Create a bitmap copy.

;))

I'm not sure if this is what you want but here is what I did.

I took your photo and made a copy at 300dpi (it is better to start with high resolution photo)

I used the Photo Tool > FX >...