... as GhostScript, calibre (epub-convert/epub-meta), ImageMagick, NirCmd, SumatraPDF, DXFView, image2pdf, PDFtk, xpdfbin (pdftotext, pdfimages,...). Ups, quite a lot, I wasn't aware of it. 8) So, my recommendation is: For test purposes, split one of those affected tiff, OCRing (with the API) all ...