advanced_image_processing: In removing_lines, switched to using numpy.isnan instead of attempting to compare.
advanced_image_processing: In removing_lines, switched to using numpy.isnan instead of attempting to compare.

jakirkham/nanshe,nanshe-org/nanshe,jakirkham/nanshe,nanshe-org/nanshe,DudLab/nanshe,DudLab/nanshe