VS 2010 turning on camera but only shows grey window - c++

Question

I'm new at this but have been doing my share of reading and trying different setups to help narrow down the problem! Any help tp get me past this road block would be much appreciated.
Currently I'm running: Win 7 Ultimate, Visual C++ 2010 Express, OpenCV 2.2.0, and a Microsoft - LifeCam Studio Webcam - Silver 1080p HD.
I'm getting no Build errors and when I run the program my camera comes on (blue light indicating it being on) and the screen pops up that i thought should show my camera feed but instead its just a grey box with nothing inside. The below code I thought would help narrow down the problem but I'm at a loss.
int main()
{
CvCapture *webcam = NULL;
webcam = cvCreateCameraCapture(-1);
if(webcam!=NULL)
{
IplImage *frame = cvQueryFrame(webcam);
cvShowImage("WEBCAM_TEST",frame);
cvWaitKey(0);
return 0;
}
else
{
std::cout<<"CAMERA NOT DETECTED"<<std::endl;
return 0;
}
}

Answer 1

your code is some times showing a black image sometimes showing a correct image on my system(Windows 7 64 VS2010 OpenCV 2.4.3)...how ever when I put it in a loop for non stop streaming the image is ok...so just modify your code slightly and try...
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <iostream>
using namespace cv;
int main()
{
CvCapture *webcam = NULL;
webcam = cvCreateCameraCapture(-1);
if(webcam!=NULL)
{
while(true)
{
IplImage *frame = cvQueryFrame(webcam);
cvShowImage("WEBCAM_TEST",frame);
cvWaitKey(20);
}
}
else
{
std::cout<<"CAMERA NOT DETECTED"<<std::endl;
return 0;
}
return 0;
}

Answer 2

In OpenCV if you get frame just after creating camera capture usually it's grey. All you have to do is just get next frame or wait before getting first frame. This code:
int _tmain(int argc, _TCHAR* argv[])
{
VideoCapture cap(0);
if(!cap.isOpened())
return -1;
Mat frame;
namedWindow("01",1);
//cap >> frame; //option 1
//waitKey(5000); //option 2
cap >> frame;
imshow("01", frame);
int key = waitKey(30);
return 0;
}
will show grey frame, but if you uncomment option 1 or option 2 - it will work fine.