How it works
Rotating
Pick pages in the grid (Shift, Ctrl or Cmd adds to the pick) and press a rotate button. With nothing picked, the buttons act on every page. The turn is added to the rotation the page already has, so a sideways scan turned right once is upright again.
Nothing is redrawn: the file only records a new rotation for the page, so text stays selectable and quality is untouched.
new rotation = (page's own rotation + turns) mod 360
Cropping
Enter how many millimetres to cut from the left, top, right and bottom as you see the page, then press Crop. The shaded strips in the preview show what will be hidden. Crops follow the page when you turn it afterwards, so a cut from the top stays a cut from the same side of the paper.
The crop sets the page's visible area (its crop box). The hidden content is still inside the file, so a viewer or a PDF editor that ignores the crop box can show it again; do not rely on cropping to remove confidential material.
visible width = page width − left − right; visible height = page height − top − bottom
