openCV打开摄像头的两个方法

方法一：

利用cvCreateCameraCapture()函数，只有一个设备的情况下默认为-1

程序如下

#include "stdafx.h"
#include "cv.h"
#include "highgui.h"
int main( int argc, char** argv ) {
cvNamedWindow( "Example1", CV_WINDOW_AUTOSIZE );
CvCapture* capture = cvCreateCameraCapture(-1);
IplImage* frame;
while(1){
frame = cvQueryFrame( capture);
if( !frame ) break;
cvShowImage( "Example1", frame );
char c = cvWaitKey(33);
if( c == 27 ) break;
}
cvReleaseCapture( &capture);
cvDestroyWindow( "Example1" );
}

方法二：

利用cvCaptureFromCAM() ，原函数形式是IplImage* cvCaptureFromCAM(int index)

程序如下

#include "stdafx.h"
#include "cv.h"
#include "highgui.h"
int main( int argc, char** argv ) {
cvNamedWindow( "Example1", CV_WINDOW_AUTOSIZE );
CvCapture* capture = cvCaptureFromCAM(0);
IplImage* frame;
while(1){
frame = cvQueryFrame( capture);
if( !frame ) break;
cvShowImage( "Example1", frame );
char c = cvWaitKey(33);
if( c == 27 ) break;
}
cvReleaseCapture( &capture);
cvDestroyWindow( "Example1" );
}