convert image_*.jpg image.pdf
V1:
convert doc.pdf -compress Zip doc_compressed.pdf
V2:
qpdf --linearize doc.pdf doc_compressed.pdf
V1:
qpdf full_doc.pdf --pages . 12-15,17-20 -- doc_pages.pdf
V2:
pdftk full_doc.pdf cat 12-15 17-20 output doc_pages.pdf
V1:
qpdf --empty --pages file1.pdf file2.pdf -- both_files.pdf
V2:
pdftk file1.pdf file2.pdf cat output both_files.pdf