Image does not display in tkinter Canvas - python-2.7

Question

I am trying to create a new class of Canvas that will be able to display and resize images. However The image does not display. I searched for similar questions and all the answers said to keep a reference of the PhotoImage in the class.( This answer for example). I tried doing that in a number of ways and none worked. In this example I tried saving a reference in a dictionary. I also tried self.tkimage = ImageTk.PhotoImage(image=img) which didn't work. And also tried using globals. I assume it has something to do with the garbage collector, but don't know how to solve.
Please assist.
import Tkinter as tk
from PIL import ImageTk, Image
import numpy as np
# a subclass of Canvas
class MyCanvas(tk.Canvas):
def __init__(self,parent,**kwargs):
tk.Canvas.__init__(self,parent,**kwargs)
self.tkimg = {}
self.images = []
self.image_on_canvas = []
def my_create_image(self, *args, **kw):
img = kw['image']
self.images.append(img)
self.tkimg[img] = ImageTk.PhotoImage(image=img)
kw['image'] = self.tkimg[img]
item = self.create_image(*args, **kw)
self.image_on_canvas.append(item)
def main():
root = tk.Tk()
myframe = tk.Frame(root)
myframe.pack(fill=tk.BOTH, expand=tk.YES)
mycanvas1 = MyCanvas(myframe, width=850, height=400, bg="red", highlightthickness=0)
mycanvas2 = MyCanvas(myframe, width=850, height=400, bg="green", highlightthickness=0)
mycanvas1.pack(side=tk.LEFT, fill=tk.BOTH, expand=tk.YES)
mycanvas2.pack(side=tk.RIGHT, fill=tk.BOTH, expand=tk.YES)
# add some widgets to the canvas
mycanvas2.create_line(0, 100, 200, 0, fill="red", dash=(4, 4))
mycanvas2.create_rectangle(50, 25, 150, 75, fill="blue")
arr1 = np.random.random([256,256])*255
img1 = Image.fromarray(arr1)
mycanvas1.my_create_image(0, 0, image=img1, anchor=tk.NW)
root.mainloop()
if __name__ == "__main__":
main()