class_docstr: example application main window 
code: def __init__(self):
      super().__init__()
      self.resize(420, 400)
      self.show()
  
      plot = self.addPlot()  # title="non-interactive")
  
      # prepare demonstration data:
      data = np.fromfunction(
          lambda i, j: (1 + 0.3 * np.sin(i)) * (i) ** 2 + (j) ** 2,
          (100, 100),
      )
      noisy_data = data * (1 + 0.2 * np.random.random(data.shape))
  
      # Example: False color image with interactive level adjustment
      img = pg.ImageItem(
          image=noisy_data
      )  # create monochrome image from demonstration data
      plot.addItem(img)  # add to PlotItem 'plot'
      cm = pg.colormap.get("CET-L9")  # prepare a linear color map
      bar = pg.ColorBarItem(
          values=(0, 20_000), cmap=cm
      )  # prepare interactive color bar
      # Have ColorBarItem control colors of img and appear in 'plot':
      bar.setImageItem(img, insert_in=plot)
  
      self.timer = pg.QtCore.QTimer(singleShot=True)
      self.timer.timeout.connect(self.export)
      self.timer.start(100)
  
file_path: pyqtgraph/doc/source/images/gen_example_false_color_image.py
imports: import numpy
  import pyqtgraph
  import pyqtgraph.exporters
  from pyqtgraph.Qt import QtCore, QtGui, QtWidgets, mkQApp
label_desc: Use image node_id 1 to create a new MainWindow object from inherited base classes: pg with example: obj = MainWindow()