The "minimal" call is: DECam_crosstalk <input_file> <output_file>. This only splits different CCDs into individual files, with no crosstalk corrections, overscanning, or trimming. Note, the default is to split into 70 files, everything but the guiding chips I presume.
-overscan is the "default" overscan setting, does line-by-line simple averaging
mean (default), median, mean with min/max values rejected. I confirmed that the overscan region is removed.
-overscan <type> ...Calls a different overscan subroutine than OverScan in DECam_crosstalk. Fewer options are available: median, 3rd order polynomial, 2nd order polynomial, 3rd order spline, 2nd order spline, mean. All of these are line-by-line.
-image_compare <another_bias> ...Reports how many pixels between frames are "significantly different". According to Robert this needs to be verified.