Can't access submitted form values in Image Cache Text Action module

I need help - I can't access submitted form values in Image Cache Text Action module function.
Actually, I need to see title and body form values when I click on PREVIEW button.
$form data object is not availiable there. I tried to catch this values even by checking $_POST data - nothing there, also in $GLOBALS, global $form also don't work, $form array is empty.
get_defined_vars() do not show me these too...
Is there any way to see my submitted values and make Image Cache Text Action generate text on canvas in Preview mode from submitted form vars? Is there any way to get these values?