sparse Matrix

import matplotlib.pyplot as plt
	import numpy as np
	class MyMatrix():
	def __init__(self, _d, _f):
	self.D = _d
	self.f = _f
	def rgbToBW(img, threshold = 120):
	bw = np.zeros((img.shape[0], img.shape[1]))
	for i in range(img.shape[0]):
	for j in range(img.shape[1]):
	if(sum(img[i,j,:])/3 > threshold):
	bw[i,j] = 1
	else:
	bw[i,j] = 0
	return bw
	def createDF(img):
	d = set()
	for i in range(img.shape[0]):
	for j in range(img.shape[1]):
	if img[i,j] == 1:
	d.add((i,j))
	f = {}
	for i,j in d:
	f[(i,j)] = 1
	return MyMatrix(d,f)
	img1 = plt.imread('test3.jpg')
	bwImg = rgbToBW(img1)
	sparseImg = createDF(bwImg)
	plt.subplot(1,2,1), plt.imshow(img1)
	plt.subplot(1,2,2), plt.imshow(bwImg, plt.cm.binary)
	plt.show()
	# In[24]:
	print(list(sparseImg.D)[0]) # sparse matris d 0. eleman
	print(str(sparseImg.f[list(sparseImg.D)[0]])) # sparse matris f 0. eleman