It is not possible to convert a PDF that contains a pattern into a viable pattern through BeadTool's transfer functions. No software can create a copy of a copy with any amount of accuracy.
If you have a PDF of a pattern that you would like to copy, you would be better off contacting the author of that pattern and asking for a revision.
If you are the author of that PDF and want to get it into BeadTool, your best bet would be to extract the image from the PDF, load that image into BeadTool and hand-trace it.