Undefined functions in opencv - c++

Question

#include<opencv\cv.h>
#include<opencv\highgui.h>
#include<opencv2\videoio.hpp>
using namespace cv;
int main(){
Mat image;
VideoCapture cap;
cap.open(0);
namedwindow("window",1);
while(1){
cap>>image;
imshow("window",image);
waitKey(33);
}
return 0;
}
when i try to run the program above i get the error that identifiers "namedWindow", "imshow" and "waitkey" are undefined.
i am coding in visual studio 2010.

Answer 1

You're including obsolete C code. To include the correct headers, use opencv2 and correct path.
Note that you can avoid all these includes, using the include all: #include <opencv2/opencv.hpp>
#include<opencv2/core/core.hpp>
#include<opencv2/highgui/highgui.hpp>
#include<opencv2/video/video.hpp>
// or use only: #include <opencv2/opencv.hpp>
using namespace cv;
int main(){
Mat image;
VideoCapture cap;
cap.open(0);
namedWindow("window", 1);
while (1){
cap >> image;
imshow("window", image);
waitKey(33);
}
return 0;
}

Answer 2

if you use
#include<opencv\cv.h>
#include<opencv\highgui.h>
you have to use different, C functions, like cvNamedWindow("title"); and cvShowImage("title", img);
Use the following C++ includes:
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/core/core.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2\opencv.hpp>
(you dont'h have to use all of them ...)