OpenCv调用摄像头拍照代码

近期在研究OpenCv对摄像头的调用。现将代码贴出，供大家批评指正。

1、申明

#include"./opencv2/opencv.hpp"

#ifdef _DEBUG

#pragma comment(lib,"opencv_core249d.lib")
#pragma comment(lib,"opencv_highgui249d.lib")

#else

#pragma comment(lib,"opencv_core249.lib")
#pragma comment(lib,"opencv_highgui249.lib")

#endif

using namespace cv;

class COpencvCameraCtrl :
	public CCameraBase
{
public:
	VideoCapture vc;
public:
	COpencvCameraCtrl(void);
	~COpencvCameraCtrl(void);

public:
	BOOL OpenCamera( HWND win, CString strVid, CString strPid );		//打开摄像头
	BOOL PhotoPic( CString strSaveFile );
	void CloseCamera();
};

2、打开摄像头

//打开摄像头
BOOL COpencvCameraCtrl::OpenCamera(HWND win, CString strVid, CString strPid)
{
	InitCameraWin( win );

	vid = strVid;
	pid = strPid;

	nIndex = GetCameraIndexInOs( vid, pid );

	if( nIndex < 0 )
	{
		return FALSE;
	}
	
	if( !vc.open( nIndex ) )
	{
		return FALSE;
	}

	vc.set( CV_CAP_PROP_FRAME_WIDTH, nWidth );
	vc.set( CV_CAP_PROP_FRAME_HEIGHT, nHight );	

	if( !vc.isOpened() )
	{
		bOpen = false;
		return FALSE;
	}

	bOpen = true;	

	return TRUE;
}

3、关闭摄像头

//关闭摄像头
void COpencvCameraCtrl::CloseCamera()
{
	if( vc.isOpened() )
	{
		vc.release();
	}	
}

4、拍照而且保存到本地

//拍摄摄像头
BOOL COpencvCameraCtrl::PhotoPic( CString strSaveFile )
{
	Mat frame;
	
	vc >> frame;
	vc >> frame;
	
	if( !frame.data )
	{
		return FALSE;
	}

	//设置图像质量
	vector<int> compression_params;
	compression_params.push_back( IMWRITE_JPEG_QUALITY );
	compression_params.push_back( 75 );

	imwrite( strSaveFile.GetBuffer(0), frame, compression_params );
	strSaveFile.ReleaseBuffer();	

	return TRUE;
}

须要说明的是：每次从摄像头获取数据到Mat，须要运行两次

Mat frame;
	
	vc >> frame;
	vc >> frame;
	
	if( !frame.data )
	{
		return FALSE;
	}

假设只运行一次，会出现两个问题：

A、假设打开摄像头马上调用拍照保存，第一次会失败，获取不到数据

B、每次拍摄保存的图片是上一次的图片