import time
import sys
import PySide
sys.modules['PyQt4'] = PySide # this little hack allows to solve naming problem when using PIL with Pyside (instead of PyQt4)
from PIL import Image, ImageQt
from PySide import QtCore,QtGui

EXAMPLE1 = 1
EXAMPLE2 = 2
EXAMPLE3 = 3

###############################################################
##### change the following variable to select the example #####
case = EXAMPLE3 ###############################################
###############################################################
###############################################################

#keep looking at your process manager to see python dedicated memory increase, and don't forget to ctrl+c :)

if __name__ == '__main__':
    
    #we just create a small blue picture for our example
    refImage = QtGui.QImage(100,100,QtGui.QImage.Format_ARGB32)
    refImage.fill(QtCore.Qt.blue)
    refImage.save('i.png','PNG')
    
    #first example
    if case == EXAMPLE1:
        print("case1")
        #load pic with pil
        im = Image.open('i.png').convert('RGBA')
        while True: # loop
            #use ImageQt to transfer it to QtImage type
            imQt = QtGui.QImage(ImageQt.ImageQt(im))
            imQt.save("o.png") #image is ok
            time.sleep(0.1)
            
    # second example, I got rid of ImageQt to show it's not directly responsible
    elif case == EXAMPLE2:
        print("case2")
        im = Image.open('i.png').convert('RGBA')
        while True: #loop
            data = im.tostring('raw','RGBA')
            imQt = QtGui.QImage(data,im.size[0],im.size[1],QtGui.QImage.Format_ARGB32)
            imQt.save("o.png") #image is ok
            time.sleep(0.1)
            
    # third case, if the data variable is out of the loop, memory stays constant
    elif case == EXAMPLE3:
        print("case3")
        im = Image.open('i.png').convert('RGBA')
        data = im.tostring('raw','RGBA')
        while True: #loop
            #data = copy.deepcopy(data) #no effect
            imQt = QtGui.QImage(data,im.size[0],im.size[1],QtGui.QImage.Format_ARGB32)
            imQt.save("o.png") #image is ok
            time.sleep(0.1)
            
#note : in examples 2 and 3, blue/red channels are inverted, this is normal, and this is the reason why PIL.Image.ImageQt() exists