I'm trying to figure out ... what is the best way to import the PDFs of Pathfinder Flipmaps and Game Mastery Map Packs into Roll20?
* What is the best way to take the map images into Roll 20?
* Is there a way to turn off gridlines?
* Is there a way to turn off the watermark with my name/email address on it?
I usually just extract the image from the pdf and save it as a jpeg or png file in Paint, then use Adobe Photoshop to increase the image size/resolution, remove any background that I don't want, crop where needed, and save it again as a jpeg or png. Afterwards I upload it to Roll20 and put it on the map layer. Then I adjust the dimensions of the map image to whatever size I need it at.
Most of the times, you won't get any of the labels on the map itself when you extract (copy) the image in the pdf file but the gridlines will be there.
Only way to avoid the gridlines in the image is if the map in question is from one of the interactive maps or an adventure path with the options to toggle grids on and off.
The watermarks shouldn't show up on the extracted image.
If you are having problems, just contact me and I can help you with a step-by-step process.