For example, you can try with the free book:
http://statweb.stanford.edu/~tibs/El...earn/main.html
http://statweb.stanford.edu/~tibs/El...II_print10.pdf
It seems to happen with many other similar examples. I understand that these are native PDF, no scan.
I tried the options provided. They change the notes captured and sometimes some whitespaces are preserved but the contents of My Clippings.txt is bad in the three cases (no options, -ocrsp, -ocrsp+).
Thanks.