Update app.py

app.py

@@ -190,4 +190,22 @@ plot(grid)
 # Once the .jpg flow images are saved, you can convert them into a video or a
 # GIF using ffmpeg with e.g.:
 #
-# ffmpeg -f image2 -framerate 30 -i predicted_flow_%d.jpg -loop -1 flow.gif
+# ffmpeg -f image2 -framerate 30 -i predicted_flow_%d.jpg -loop -1 flow.gif
+
+def write_flo(filename, flow):
+    """
+    write optical flow in Middlebury .flo format
+    :param flow: optical flow map
+    :param filename: optical flow file path to be saved
+    :return: None
+    """
+    f = open(filename, 'wb')
+    magic = np.array([202021.25], dtype=np.float32)
+    (height, width) = flow.shape[0:2]
+    w = np.array([width], dtype=np.int32)
+    h = np.array([height], dtype=np.int32)
+    magic.tofile(f)
+    w.tofile(f)
+    h.tofile(f)
+    flow.tofile(f)
+    f.close()