I need to process multi-page PDFs that are scanned in to me using a program I wrote in C++ using OpenCV libraries. OpenCV does not read in PDFs, so I am currently using pdftk to break up the PDF, and convert -density 300 page##.pdf page##.png to convert the individual pages to PNGs before reading them in with my program.
The issue is convert takes about 30 seconds on my Raspberry Pi to do this conversion. Is there an easier way to convert multi-page PDFs in a way that can be read in my C++/OpenCV?
You can try converting PDF to PNG with
http://www.foolabs.com/xpdf/
https://github.com/coolwanglu/pdf2htmlEX (it convert PDF to html, but do generate png as images corresponding to each page, which can be used)