PySABER is a python package for characterizing the X-ray source and detector blur in cone-beam X-ray imaging systems. SABER is an abbreviation for Systems Approach to Blur Estimation and Reduction. Note that even parallel beam X-rays in synchrotrons are in fact cone beams albeit with a large source to object distance. X-ray images, also called radiographs, are simultaneously blurred by both the X-ray source spot blur and detector blur. This package uses a numerical optimization algorithm to disentangle and estimate both forms of blur simultaneously.