Proper error message, Check if grab() was successfull

AutonomousMode/Input/input.cpp

@@ -39,13 +39,15 @@ Mat Input::readWebcam()
     Mat image;
 
     if(!cap.isOpened()) {
-        cout << "Fehler";
+        cout << "Video capture not opened" << std::endl;
         return Mat();
     }
 
-    cap.grab();
+    if(!cap.grab()) {
+        cout << "Could not grab frame from camera" << std::endl;
+        return Mat();
+    }   
     cap.retrieve(image);
-    
     return image;  
 }
 

AutonomousMode/autonomous_mode_main.cpp

@@ -7,8 +7,8 @@ int main(void)
     cv::utils::logging::setLogLevel(cv::utils::logging::LOG_LEVEL_WARNING);
 
     const int thresholdBinary = 140;
-    const int videoHeight = 240;
-    const int videoWidth = 320;
+    const int videoHeight = 720;
+    const int videoWidth = 1280;
     const int gaussKernelSize = 21;
     const int thresholdCanny1 = 50;
     const int thresholdCanny2 = 100;