SIM_GRAYSCALE
ss->sio.scan_image_mode = SIM_GRAYSCALE;
case SIM_GRAYSCALE:
case SIM_GRAYSCALE:
case SIM_GRAYSCALE:
ss->sio.scan_image_mode = SIM_GRAYSCALE;
case SIM_GRAYSCALE:
case SIM_GRAYSCALE:
case SIM_GRAYSCALE:
if (ss->sio.scan_image_mode < SIM_GRAYSCALE)