  The MagAO-X instrument is an upgrade of the Magellan AO system that will
introduce extreme adaptive optics capabilities for high-contrast imaging at
visible and near-infrared wavelengths. A central component of this system is a
2040-actuator microelectromechanical (MEMS) deformable mirror (DM) from Boston
Micromachines Corp. (BMC) that will operate at 3.63 kHz for high-order
wavefront control. Two additional DMs from ALPAO will perform low-order and
non-common-path science-arm wavefront correction. The accuracy of the wavefront
correction is limited by our ability to command these DMs to a desired shape,
which requires a careful characterization of each DM surface. We have developed
a characterization pipeline that uses a Zygo Verifire Interferometer to measure
the surface response and a Karhunen-Lo\`eve transform to remove noise from our
measurements. We present our progress in the characterization process and the
results of our pipeline applied to an ALPAO DM97 and a BMC Kilo-DM,
demonstrating the ability to drive the DMs to a flat of $\lesssim$ 2nm and
$\lesssim$ 4nm RMS in our beam footprint on the University of Arizona Wavefront
Control (UAWFC) testbed.
