Scanning an image is actually the least preferred method, VituixCAD is meant to be used with real measured data from systems like ARTA, REW, SoundEasy, Clio, etc.
So you can import any csv / frd type of data, or complete IR to FR processing using impulse response exported directly from ARTA, REW, etc.
For the csv files you have, try simply loading directly to the driver response. Connect driver to source in the crossover to view the response. May need to rename to .txt