snapshot opencv

//func with opencv shot with webcam
void webcam(const char* file)
{
 CvCapture *capture = cvCreateCameraCapture(0);
   if(capture==NULL)
    puts( "nao he possivel pegar foto!\n");

  IplImage* frame = cvQueryFrame( capture );
   if(!frame)
    puts( "erro na foto!\n");

  int imageParams[3] = {CV_IMWRITE_JPEG_QUALITY, 100, 0};
  cvSaveImage(file , frame,imageParams);
  cvReleaseCapture( &capture );
}