1# -*- coding: utf-8 -*- 2""" 3Demonstrate ability of ImageItem to be used as a canvas for painting with 4the mouse. 5 6""" 7 8import initExample ## Add path to library (just for examples; you do not need this) 9 10 11from pyqtgraph.Qt import QtCore, QtGui 12import numpy as np 13import pyqtgraph as pg 14 15app = pg.mkQApp("Draw Example") 16 17## Create window with GraphicsView widget 18w = pg.GraphicsView() 19w.show() 20w.resize(800,800) 21w.setWindowTitle('pyqtgraph example: Draw') 22 23view = pg.ViewBox() 24w.setCentralItem(view) 25 26## lock the aspect ratio 27view.setAspectLocked(True) 28 29## Create image item 30img = pg.ImageItem(np.zeros((200,200))) 31view.addItem(img) 32 33## Set initial view bounds 34view.setRange(QtCore.QRectF(0, 0, 200, 200)) 35 36## start drawing with 3x3 brush 37kern = np.array([ 38 [0.0, 0.5, 0.0], 39 [0.5, 1.0, 0.5], 40 [0.0, 0.5, 0.0] 41]) 42img.setDrawKernel(kern, mask=kern, center=(1,1), mode='add') 43img.setLevels([0, 10]) 44 45if __name__ == '__main__': 46 pg.exec() 47