Generate sandwich OCR PDFs from scanned file

Current versions

pdfsandwich requires the following formulae to be installed:
gawk 4.2.0_1 GNU awk utility
ocaml 4.06.0 General purpose programming language in the ML family
exact-image 1.0.1 Image processing library
ghostscript 9.22 Interpreter for PostScript and PDF
imagemagick 7.0.7-22 Tools and libraries to manipulate images in many formats
poppler 0.62.0 PDF rendering library (based on the xpdf-3.0 code base)
tesseract 3.05.01 OCR (Optical Character Recognition) engine
unpaper 6.1_1 Post-processing for scanned/photocopied books

Recent formula history

ilovezfs pdfsandwich: fix for unlinked poppler
Jonatan Lindén pdfsandwich 0.1.6 (new formula)

Formula code at GitHub