docs: def update_image(self, data):
          """
          update image on panel, as quickly as possible
          """
          if 1 in data.shape:
              data = data.squeeze()
          if self.conf.contrast_level is not None:
              clevels = [self.conf.contrast_level, 100.0-self.conf.contrast_level]
              imin, imax = np.percentile(data, clevels)
              data = np.clip((data - imin)/(imax - imin + 1.e-8), 0, 1)
          self.axes.images[0].set_data(data)
          self.canvas.draw()