  Astrophysical black hole candidates are thought to be the Kerr black holes
predicted by General Relativity, but the actual nature of these objects has
still to be proven. The analysis of the electromagnetic radiation emitted by a
geometrically thin and optically thick accretion disk around a black hole
candidate can provide information about the geometry of the space-time around
the compact object and it can thus test the Kerr black hole hypothesis. In this
paper, I present a code based on a ray-tracing approach and capable of
computing some basic properties of thin accretion disks in space-times with
deviations from the Kerr background. The code can be used to fit current and
future X-ray data of stellar-mass black hole candidates and constrain possible
deviations from the Kerr geometry in the spin parameter-deformation parameter
plane.
