ROS2上使用WeChatQRdetector扫码二维码
微信的扫码算法对机器人在运动过程中产生的模糊、畸变有极强的识别率。ROS 2 社区有基于 OpenCV 编译的wechat_qrcode节点。
功能包推荐：
ros2_wechat_qrcode或自行编写节点调用 OpenCV 的wechat_qrcode模块。工作流：摄像头驱动节点发布图像话题（Topic） 扫码节点订阅并解析 发布识别到的字符串话题
wechat_qrcode的主要功能实现依赖于detect.prototxt，detect.caffemodel，sr.prototxt，sr.caffemodel这样的四个模型文件。这四个文件可以在https://github.com/WeChatCV/opencv_3rdparty/tree/wechat_qrcode下载，同时opencv官网也提供该函数的使用说明。
整个文件夹架构
ros2_ws/
├─ src/
│ └─ qrcode_detector/
│ ├─ package.xml
│ ├─ setup.py
│ ├─ setup.cfg
│ ├─ resource/
│ │ └─ qrcode_detector
│ ├─ qrcode_detector/
│ │ ├─ __init__.py
│ │ └─ qrcode_node.py
│ ├─ launch/
│ │ └─ qrcode_detector.launch.py
│ └─ models/
│ ├─ detect.prototxt
│ ├─ detect.caffemodel
│ ├─ sr.prototxt
│ └─ sr.caffemodel
将下载好的四个模型文件复制进models文件夹后然后在代码里用 ROS2 的 package share 路径读取
关键是：
models/需要被安装到 ROS2 的share目录。你的setup.py里要加上：
from glob import glob import os setup( name='qrcode_detector', # ... data_files=[ ('share/ament_index/resource_index/packages', ['resource/qrcode_detector']), ('share/qrcode_detector', ['package.xml']), (os.path.join('share', 'qrcode_detector', 'models'), glob('models/*')), (os.path.join('share', 'qrcode_detector', 'launch'), glob('launch/*.py')), ], )然后在节点文件里面拿到路径
import os import cv2 as cv from ament_index_python.packages import get_package_share_directory pkg_share = get_package_share_directory('qrcode_detector') model_dir = os.path.join(pkg_share, 'models') detector = cv.wechat_qrcode.WeChatQRCode( os.path.join(model_dir, 'detect.prototxt'), os.path.join(model_dir, 'detect.caffemodel'), os.path.join(model_dir, 'sr.prototxt'), os.path.join(model_dir, 'sr.caffemodel'), )最后再使用解码模块进行解码得到信息
import os import cv2 as cv from ament_index_python.packages import get_package_share_directory import rclpy from rclpy.node import Node from sensor_msgs.msg import Image from cv_bridge import CvBridge pkg_share = get_package_share_directory('line_follower_pkg') model_dir = os.path.join(pkg_share, 'models') detector = cv.wechat_qrcode.WeChatQRCode( os.path.join(model_dir, 'detect.prototxt'), os.path.join(model_dir, 'detect.caffemodel'), os.path.join(model_dir, 'sr.prototxt'), os.path.join(model_dir, 'sr.caffemodel'), ) class WeChatQR(Node): def __init__(self): super().__init__('wechat_qr') self.bridge = CvBridge() self.subscription = self.create_subscription( Image, 'your topic', self.image_callback, 10 ) self.subscription # prevent unused variable warning def image_callback(self, msg): cv_image = self.bridge.imgmsg_to_cv2(msg, desired_encoding='bgr8') decoded_info, points = detector.detectAndDecode(cv_image) if decoded_info: for info in decoded_info: self.get_logger().info(f'Decoded QR Code: {info}') def destroy_node(self): self.cap.release() super().destroy_node() def main(args=None): rclpy.init(args=args) node = WeChatQR() try: rclpy.spin(node) except KeyboardInterrupt: pass finally: node.destroy_node() rclpy.shutdown() if __name__ == '__main__': main()