idiomatic code in camera_data

Author: carloskiki

camera_data/src/camera_publisher.py

@@ -1,16 +1,13 @@
 #!/usr/bin/env python3
 import os, sys
-from pydoc_data.topics import topics
 
 currentdir = os.path.dirname(os.path.realpath(__file__))
 sys.path.append(currentdir)
 import rospy
 import cv2
-import time
 from cv_bridge import CvBridge
 from sensor_msgs.msg import Image
 from std_msgs.msg import Int16
-from PyQt5 import QtGui
 import sys
 
 stop = False
@@ -24,23 +21,20 @@ def __init__(self):
 
         rospy.init_node('camera_frame_publisher')
         self.camera_select_subscriber = rospy.Subscriber("camera_selection", Int16, self.select_camera)
-        self.timer = rospy.Timer(rospy.Duration(0.03), self.timer_callback)
+        _30fps_ns = 30000000
+        self.timer = rospy.Timer(rospy.Duration(0, _30fps_ns), self.timer_callback)
         self.camera_frame_publisher = rospy.Publisher('/camera_frames', Image, queue_size=10)
 
-    def timer_callback(self, event):
-        try:
-            ret, frame = self.video_capture.read()
-            # these code cause error
-            encode_params = [int(cv2.IMWRITE_JPEG_QUALITY), 90]
-            result, frame = cv2.imencode(".jpg", frame, encode_params)
+    def timer_callback(self, _):
+        ret, frame = self.video_capture.read()
+        if ret:
+            encode_params = [cv2.IMWRITE_JPEG_QUALITY, 90]
+            _, frame = cv2.imencode(".jpg", frame, encode_params)
             self.frames = self.openCV_to_ros_image(frame)
-            if ret:
-                print("Publishing frame")
-                self.camera_frame_publisher.publish(self.frames)
-        except:
+            print("Publishing frame")
+            self.camera_frame_publisher.publish(self.frames)
+        else: 
             print("No camera found")
-        finally:
-            pass
 
     def openCV_to_ros_image(self, cv_image):
         try:

camera_data/src/camera_subscriber.py

@@ -1,10 +1,8 @@
 import os, sys
-from pydoc_data.topics import topics
 currentdir = os.path.dirname(os.path.realpath(__file__))
 sys.path.append(currentdir)
+
 import rospy
-currentdir = os.path.dirname(os.path.realpath(__file__))
-sys.path.append(currentdir)
 import cv2
 from sensor_msgs.msg import Image
 from cv_bridge import CvBridge
@@ -34,4 +32,4 @@ def ros_to_openCV_image(self, ros_image):
 
 if __name__ == "__main__":
     driver = Node_CameraFrameSub()
-    rospy.spin()
+    rospy.spin()

camera_data/src/getCameraFeeds.py

@@ -2,44 +2,41 @@
 
 
 class CameraHandler:
-    vids = []  # available cameras
+    available_cameras = []
 
     def __init__(self):
-        # Loop 25 times and collect all found cameras
+        # Collect all found cameras
         # Assumes sequential indices
         for i in range (25):
             newCap = cv2.VideoCapture(i, cv2.CAP_V4L2)
 
-            if newCap is not None:
-                newCap.open(i)
-
-            # check if object is not null
-            if newCap is not None and newCap.isOpened():
-                # add the camera found
-                self.vids.append(newCap)
+            if newCap is not None and newCap.open(i):
+                self.available_cameras.append(newCap)
 
     def get_all_feeds(self):
         retAndFrame = []
         # read each capture object in vids and add as a tuple to retAndFrame
-        for i in range(len(self.vids)):
-            newFeed = self.vids[i].read()
-            retAndFrame.append((newFeed[0], newFeed[1], i))
+        for camera in self.available_cameras:
+            newFeed = camera.read()
+            retAndFrame.append((newFeed[0], newFeed[1]))
 
         return retAndFrame
 
-# # Runnable for displaying camera feeds
+    def run_feeds(self):
+        while True:
+            # display each frame (camera feed) in the list
+            for index, (ret, frame) in enumerate(self.get_all_feeds()):
+                if ret:
+                    cv2.imshow(f"frame {index}", frame)
+
+            # press 'q' to stop displaying
+            if cv2.waitKey(1) & 0xFF == ord('q'):
+                for vid in self.available_cameras:
+                    vid.release()
+                    cv2.destroyAllWindows()
+                break
+
+# Runnable to display camera feeds
 if __name__ == '__main__':
     camHandler = CameraHandler()
-    while True:
-        retAndFrame = camHandler.get_all_feeds()
-        # display each frame (camera feed) in the list
-        for ret, frame, index in retAndFrame:
-            if ret:
-                cv2.imshow(f"frame {index}", frame)
-
-        # press 'q' to stop displaying
-        if cv2.waitKey(1) & 0xFF == ord('q'):
-            for vid in camHandler.vids:
-                vid.release()
-                cv2.destroyAllWindows()
-            break
+    camHandler.run_feeds()

camera_data/test/test_getCam.py

@@ -1,4 +1,3 @@
-import cv2
 import sys
 import os
 
@@ -9,18 +8,6 @@
 
 import getCameraFeeds as gcf
 
-# Runnable for displaying camera feeds
+# Runnable to display camera feeds
 camHandler = gcf.CameraHandler()
-while True:
-    retAndFrame = camHandler.get_all_feeds()
-    # display each frame (camera feed) in the list
-    for ret, frame, index in retAndFrame:
-        cv2.imshow(f"frame {index}", frame)
-
-    # press 'q' to stop displaying
-    if cv2.waitKey(1) & 0xFF == ord('q'):
-        for vid in camHandler.vids:
-            vid.release()
-            cv2.destroyAllWindows()
-        break
-
+camHandler.run_feeds()