It would be great if there was some tool to measure distances (in points, mm, cm, dpi) and perhaps areas in an PDF. I'd imagine zooming in as much as necessary, then choosing the measurement tool, and dragging a line (resp. a rectangle) on the screen; either the status bar or a hovering popup could show the distance in some choosable units (one or multiple). Thanks a lot!
additional to just being able to measure sheet distance allowing for a scaling option on the reported distance would make Okular incredibly useful for the Architecture, Engineering, and Construction (AEC) market. We typically need to scale dimensions from drawings and right now the opensource options for this are extremely limited to work arounds with either InkScape or GIMP.