code: def reset_scale_skew(self):
          
          chnames = self.fv.get_channel_names()
          for chname in chnames:
              chinfo = self.fv.get_channel(chname)
  
              scales = chinfo.fitsimage.get_scale_xy()
              fac = min(*scales)
              chinfo.fitsimage.scale_to(fac, fac)
docs: Set the X/Y scaling factors to be equal in each channel.