if your jig is the size of the dots that is a start , drop the jig and compare the size on the screen ...
if they appear larger than the jig , ketch a few to get a better idea , more often than not , crappie on LS that are decent size look ALOT bigger than your jig when you drop it ,just saying
on a side note , big crappie often stay SO tight to stuff and are not easily spotted ....fyi