Eye tracker calibration with custom image

Hi,

We have been using the Builder to create our experiment. We also used the new calibration component to add to calibration procedure (SR Research Eyelink Portable Duo), but we would like to use a .jpg file as the calibration target instead of a color dot. Since the Builder does not offer the option, would that be possible to modify the experiment script to do that? Any suggestion is appreciated.

Thank you,
Gorecki