- added image module with sub image and normalize

- improved tests

src/tests/test_sub_image.py

@@ -0,0 +1,19 @@
+from rbm.image import SubImage
+from rbm.matrix import np
+
+
+if __name__ == "__main__":
+	n = 2
+	c = 3
+	w = 8
+	h = 8
+	img = np.reshape(np.linspace(1, n*c*w*h, num=n*c*w*h, dtype=np.float64), (n, c, w, h))
+#	print(img)
+
+	sub = SubImage(4, 4, 1, 1)
+
+	images = sub(img)
+	print(images)
+
+
+	print("Test: [passed]")