Make compatible for 1 channel only & Update frames handling#2

Open

jonasfbraun wants to merge 2 commits intomasterfrom

update_frames_handling

Commits on Oct 8, 2020

included some 'if stack2 is not None else None' to make it compatible with using just one channel
jonasfbraun
committed

Commits on Apr 23, 2021

cleaned up how frames and ref_frame are handled in motion_compensate. Added progress bars for both parallel (in verbose mode) and non-parallel processing.
jonasfbraun
committed