I use GIMP, which is an open source, free graphical editor that runs on Windows, Mac, or Linux (my operating system of choice).
I photograph my own ink stuff, and here's how I edit them:
(1) crop to paper edges only.
(2) colorify to grayscale, removing all color.
(3) use the automatic white balance adjustor
(4) bump up the contrast until the white paper looks white.
(5) use free select to select areas that might still appear unnaturally gray.
(6) bump up the contrast a bit more, but not so much that your ink marks begin to disappear.
I'll download one of your pics, adjust it, and upload to see if you like what my method can do.
Last edited by bbbaldie; 03-14-2016 at 01:10 PM.