code: def _reduce_opacity(self):
          
          if self.image.mode != 'RGBA':
              image = self.image.convert('RGBA')
          else:
              image = self.image.copy()
  
          alpha = image.split()[3]
          alpha = ImageEnhance.Brightness(alpha).enhance(self.opacity)
          image.putalpha(alpha)
  
          self.image = image
docs: Reduce opacity for watermark image.