Conversion Between ROS imgmsg and OpenCV: cv_bridge Example (Python)

# Synopsis - 如何在OpenCV与ROS图像消息之间进行转换 - [Converting between ROS images and OpenCV images (Python)]( # Create Package ```sh catkin_create_pkg cvbridge_example sensor_msgs cv_bridge rospy std_msgs ``` Note that: Please do not add "opencv2" here. # Converting ROS image messages to OpenCV images ```python from from cv_bridge import CvBridge bridge = CvBridge() cv_image = bridge.imgmsg_to_cv2(image_message, desired_encoding='passthrough') ``` # Converting OpenCV images to ROS image messages ```python from cv_bridge import CvBridge bridge = CvBridge() image_message = bridge.cv2_to_imgmsg(cv_image, encoding="passthrough") ``` # Python Exampe ```python #!/usr/bin/env python from __future__ import print_function import roslib roslib.load_manifest('cvbridge_example') import sys import rospy import cv2 from std_msgs.msg import String from sensor_msgs.msg import Image from cv_bridge import CvBridge, CvBridgeError class image_converter: def __init__(self): self.image_pub = rospy.Publisher("result_image",Image) self.bridge = CvBridge() self.image_sub = rospy.Subscriber("/camera/rgb/image_color",Image,self.callback) def callback(self,data): try: cv_image = self.bridge.imgmsg_to_cv2(data, "bgr8") except CvBridgeError as e: print(e) (rows,cols,channels) = cv_image.shape if cols > 60 and rows > 60 :, (50,50), 10, 255) cv2.imshow("Image window", cv_image) cv2.waitKey(3) try: self.image_pub.publish(self.bridge.cv2_to_imgmsg(cv_image, "bgr8")) except CvBridgeError as e: print(e) def main(args): ic = image_converter() rospy.init_node('image_converter', anonymous=True) try: rospy.spin() except KeyboardInterrupt: print("Shutting down") cv2.destroyAllWindows() if __name__ == '__main__': main(sys.argv) ``` # Run example ```sh chmod +x rosrun cvbridge_example ``` Play bag file manually. For example, TUM bag file. # Result

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