Scanning

General phone procedure

  • Use autoscan on a good app - or a bluetooth trigger.
    • check the quality of images, and rescan the misscanned pages
  • transfer the images to desktop, or produce pdf on phone

doc scanner

auto-capture mode has made it perfect for digitizing Sanskrit documents. - mohit dokania

Camscanner

No good OCR - just scanning.

  • Auto-scan video .
  • Support for generating 2 page images from single photo - only in non-automatic mode.

vflat

  • android, apple
  • Auto-scan video .
  • free app - Scanning and exporting images - no restrictions. pdf making restricted to 10 images.
  • generates 2 page images from single photo well. But there is a monthly limit.

pdf processing

Splitting multi-page/ column pages

  • scantailor advanced does an excellent automated job, if used right. kArtik uses it.

    • sudo flatpak install flathub org.scantailor.Scantailor-advanced
    • Input and output - images, not pdfs. Outputs tiffs.
      • Input - mkdir images; pdftoppm -jpeg input.pdf images/page
      • Output - mogrify -format jpg -quality 85 *.tif
      • img2pdf --pagesize A4 --fit shrink *.jpg -o output.pdf
    • Must run various stages sequentially -
      • split pages, fix page box, set margins, output ….
      • Stage settings
        • no content selection, don’t set margins
        • color output, white fill.
      • Click on all visible apply-to buttons to select target pages. Eg. Big Mode rectangle includes one “apply to” button despite many options.
    • Software Settings - jpg output;

  • can be done with pdfarranger - but can be laborious if facing page proportions are not uniform

  • briss is more automated. Still - makes errors. Can make overlapping rectangles.

    • Source: GH

  • can open the pdf on computer, and use adobe scan on phone with 2-page mode on it.

pdf compression

  • gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/ebook -dNOPAUSE -dQUIET -dBATCH -sOutputFile=alt.pdf tirukkural_alt_2.pdf
  • small pdf or similar online resources