Make the flip_image_cb a local function.

This lets us get the is_flipped message out of the global
namespace.

Signed-off-by: Chris Lalancette <[email protected]>

Author: clalancette

image_tools_py/src/cam2image_py.py

@@ -29,17 +29,6 @@
 import burger_py
 import image_qos_profile
 
-is_flipped = False
-
-
-def flip_image_cb(msg):
-    global is_flipped
-    is_flipped = msg.data
-
-    output = 'on' if is_flipped else 'off'
-
-    print('Set flip mode to: ' + output)
-
 
 # Convert an OpenCV matrix encoding type to a string format recognized by
 # sensor_msgs::Image
@@ -124,6 +113,17 @@ def main():
     # Create the image publisher with our custom QoS profile.
     pub = node.create_publisher(sensor_msgs.msg.Image, 'image', custom_camera_qos_profile)
 
+    is_flipped = False
+
+    def flip_image_cb(msg):
+        nonlocal is_flipped
+
+        is_flipped = msg.data
+
+        output = 'on' if is_flipped else 'off'
+
+        print('Set flip mode to: ' + output)
+
     custom_flip_qos_profile = qos_profile_sensor_data
     custom_flip_qos_profile.depth = 10
     node.create_subscription(
@@ -154,7 +154,6 @@ def main():
 
         # Check if the frame was grabbed correctly.
         if frame is not None:
-            global is_flipped
             # Convert to a ROS image
             if is_flipped:
                 # Flip the frame if needed