tensorflow >= 2.5.0
numpy
protobuf < 4.0  # XXX https://github.com/OCR-D/ocrd_calamari/issues/89
calamari-ocr == 1.0.*, >= 1.0.6
setuptools >= 41.0.0  # tensorboard depends on this, but why do we get an error at runtime?
click
ocrd >= 2.22.0