11 April 2017 - A Bit More Than Mostly Searchable: Scanned Paper You Can Find with Stewart Russell

9 May - Lessons learnt as a maintainer with Dhaval Giani

13 June - Intelligent Availability; The evolution of High Availability with Madison Kelly

PDF 32000-1:2008 standard and accompanying Public Patent License.

PDF/A archival format: Creating a PDF/A document from PostScript in ghostscript, converting a PDF to PDF/A: gs -dPDFA -dBATCH -dNOPAUSE -dUseCIEColor -sProcessColorModel=DeviceCMYK -sDEVICE=pdfwrite -sPDFACompatibilityPolicy=1 -sOutputFile=output_filename.pdf input_filename.pdf. If you need to work out if the document is colour or not, ghostscript's inkcov device can tell you if colour was used at all.

Cryptographic signing: Rough process here, using an X.509 certificate issued by ARRL: Creating secure digital QSL cards with your LoTW certificate. I wonder if you could use P12 certs issued by Let’s Encrypt?

tesseract -psm 0 … will output orientation and language heuristics, useful if your scanner spits out duplex pages flipped. It's a bit slow, but faster than manually digging through a PDF object stream looking at the individual convolution matrices.

training tesseract is definitely worth it if you have a limited domain, say line-printed numerals. (You might have less success with the completely illegible old German Sütterlin cursive, though.)