+import Image as im
+import numpy as np
+
+cover = im.open("lena512.bmp")
+cover.save("lena512.png")
+
+d7= im.open("diff7.pgm")
+d7.save("diff7.png")
+d7= im.open("diff7.png")
+
+l6 = im.open("lena6.pgm")
+l6.save("lena6.png")
+
+l7 = im.open("lena7.pgm")
+l7.save("lena7.png")
+
+
+e6 = im.open("edge6.pgm")
+e6.save("edge6.png")
+
+e7 = im.open("edge7.pgm")
+e7.save("edge7.png")
+
+
+d6= im.open("diff6.pgm")
+d6.save("diff6.png")
+d6= im.open("diff6.png")
+
+print d7.size
+m7 = d7.getdata()
+m6 = d6.getdata()
+
+r7= {}
+
+for e in m7:
+ if e not in r7:
+ r7[e] = 1
+print r7
+
+r6={}
+for e in m6:
+ if e not in r6:
+ r6[e] = 1
+print r6
+
