  KMOS is a multi-object near-infrared integral field spectrometer with 24
deployable cryogenic pick-off arms. Inevitably, data processing is a complex
task that requires careful calibration and quality control. In this paper we
describe all the steps involved in producing science-quality data products from
the raw observations. In particular, we focus on the following issues: (i) the
calibration scheme which produces maps of the spatial and spectral locations of
all illuminated pixels on the detectors; (ii) our concept of minimising the
number of interpolations, to the limiting case of a single reconstruction that
simultaneously uses raw data from multiple exposures; (iii) a comparison of the
various interpolation methods implemented, and an assessment of the performance
of true 3D interpolation schemes; (iv) the way in which instrumental flexure is
measured and compensated. We finish by presenting some examples of data
processed using the pipeline.
