improve resolution

test/src/QRcode.cpp

@@ -64,13 +64,20 @@ void processFrame(const cv::Mat& frame)
 
 void frameProcessingThread()
 {
-    cv::VideoCapture cap(0); // Open the default camera
+    cv::VideoCapture cap(0, cv::CAP_V4L2); // Open the default camera with V4L2 backend
     if (!cap.isOpened())
     {
         ROS_ERROR("Unable to open camera");
         return;
     }
 
+    // Set the desired resolution
+    cap.set(cv::CAP_PROP_FRAME_WIDTH, 1920); // Set width to 1920 pixels
+    cap.set(cv::CAP_PROP_FRAME_HEIGHT, 1080); // Set height to 1080 pixels
+
+    // Set the desired frame rate
+    cap.set(cv::CAP_PROP_FPS, 15); // Set frame rate to 15 Hz
+
     while (ros::ok())
     {
         cv::Mat frame;