Make image_cb a locally defined function so we can keep args local to main().

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

Author: clalancette

image_tools_py/src/showimage_py.py

@@ -28,8 +28,6 @@
 # Local imports
 import image_qos_profile
 
-args = None
-
 
 def encoding2mat(encoding):
     if encoding.startswith('mono'):
@@ -51,30 +49,7 @@ def encoding2mat(encoding):
     return dtype, channels
 
 
-def image_cb(msg):
-    global args
-
-    print("Received image #" + msg.header.frame_id)
-
-    if args.show_camera:
-        dtype, n_channels = encoding2mat(msg.encoding)
-        dtype = numpy.dtype(dtype)
-        dtype = dtype.newbyteorder('>' if msg.is_bigendian else '<')
-        if n_channels == 1:
-            frame = numpy.ndarray(shape=(msg.height, msg.width),
-                                  dtype=dtype, buffer=bytes(msg.data))
-        else:
-            frame = numpy.ndarray(shape=(msg.height, msg.width, n_channels),
-                                  dtype=dtype, buffer=bytes(msg.data))
-
-        cv2.imshow("showimagepy", frame)
-        # Draw the image to the screen and wait 1 millisecond
-        cv2.waitKey(1)
-
-
 def main():
-    global args
-
     # Pass command-line arguments to rclpy.
     rclpy.init(sys.argv)
 
@@ -108,6 +83,25 @@ def main():
                                                               args.reliability_policy,
                                                               args.keep)
 
+    def image_cb(msg):
+        print("Received image #" + msg.header.frame_id)
+
+        if args.show_camera:
+            dtype, n_channels = encoding2mat(msg.encoding)
+            dtype = numpy.dtype(dtype)
+            dtype = dtype.newbyteorder('>' if msg.is_bigendian else '<')
+            if n_channels == 1:
+                frame = numpy.ndarray(shape=(msg.height, msg.width),
+                                      dtype=dtype, buffer=bytes(msg.data))
+            else:
+                frame = numpy.ndarray(shape=(msg.height, msg.width, n_channels),
+                                      dtype=dtype, buffer=bytes(msg.data))
+
+            cv2.imshow("showimagepy", frame)
+            # Draw the image to the screen and wait 1 millisecond
+            cv2.waitKey(1)
+
+
     node.create_subscription(sensor_msgs.msg.Image, 'image',
                              image_cb, custom_qos_profile)