Scan images in Gray, 600 dpi, after preview.
Save as tiff.
Open in Photoshop, straighten, crop.
Save as png.
Open in Fiji/ImageJ.
FFT
Blacken all stars.
http://photo.stackexchange.com/questions/23445/what-is-the-best-way-to-remove-texture-from-a-scanned-textured-photo-paper
Inverse FFT
Save as TIFF.
Open in Photoshop.
Add Curve adjustment layers.