I'm trying to implement an automated paper form evaluation, which first needs to align the scanned sheet. Previously I used a selfmade alignment algorithm using lines, this worked but was neither very accurate nor robust. So I looked into OpenCV and found ArUco and many other fiducial markers, but I read somewhere that ArUco does not provide the best positional accuracy. What I'm missing is some kind of comparison (table) of fiducial markers with their pros and cons. If this does not exist: What is the best marker for maximum positional accuracy in 2D (no perspective)?