之前使用OpenCV 自带的函数打开摄像头，在Win7下无法使用的朋友可以参考一下这篇文章。使用DirectShow可以实现打开多个摄像头。首先从网上下载三个文件：DirectShow、CameraDS.cpp、CameraDS.h其中DirectShow是一个文件夹，没必要下载安装程序，DirectShow里面包含了lib文件与Include头文件。接下来是配置DirectShow，新建一个MFC工程，然后在文件一栏添加CameraDS.cpp与CameraDS.h到工程里，还要在工程的.cpp文件哪里添加DirectShow的头文件。比如
//以下fordirectshow#include "camerads.h" #include <stdio.h> #include <stdarg.h> #include <time.h>
接下来就可以着手写打开摄像通头的程序了。以下是相关代码：
// 行人检测Dlg.cpp : implementation file
//
#include "stdafx.h"
#include "行人检测.h"
#include "行人检测Dlg.h"
#include <cv.h>
#include <cxcore.h>
#include <highgui.h>
//以下fordirectshow
#include "camerads.h"
#include <stdio.h>
#include <stdarg.h>
#include <time.h>
#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif
/////////////////////////////////////////////////////////////////////////////
// CAboutDlg dialog used for App About
class CAboutDlg : public CDialog
{
public:
CAboutDlg();
// Dialog Data
//{{AFX_DATA(CAboutDlg)
enum { IDD = IDD_ABOUTBOX };
//}}AFX_DATA
// ClassWizard generated virtual function overrides
//{{AFX_VIRTUAL(CAboutDlg)
protected:
virtual void DoDataExchange(CDataExchange* pDX); // DDX/DDV support
//}}AFX_VIRTUAL
// Implementation
protected:
//{{AFX_MSG(CAboutDlg)
//}}AFX_MSG
DECLARE_MESSAGE_MAP()
};
CAboutDlg::CAboutDlg() : CDialog(CAboutDlg::IDD)
{
//{{AFX_DATA_INIT(CAboutDlg)
//}}AFX_DATA_INIT
}
void CAboutDlg::DoDataExchange(CDataExchange* pDX)
{
CDialog::DoDataExchange(pDX);
//{{AFX_DATA_MAP(CAboutDlg)
//}}AFX_DATA_MAP
}
BEGIN_MESSAGE_MAP(CAboutDlg, CDialog)
//{{AFX_MSG_MAP(CAboutDlg)
// No message handlers
//}}AFX_MSG_MAP
END_MESSAGE_MAP()
/////////////////////////////////////////////////////////////////////////////
// CMyDlg dialog
CMyDlg::CMyDlg(CWnd* pParent /*=NULL*/)
: CDialog(CMyDlg::IDD, pParent)
{
//{{AFX_DATA_INIT(CMyDlg)
// NOTE: the ClassWizard will add member initialization here
//}}AFX_DATA_INIT
// Note that LoadIcon does not require a subsequent DestroyIcon in Win32
m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}
void CMyDlg::DoDataExchange(CDataExchange* pDX)
{
CDialog::DoDataExchange(pDX);
//{{AFX_DATA_MAP(CMyDlg)
// NOTE: the ClassWizard will add DDX and DDV calls here
//}}AFX_DATA_MAP
}
BEGIN_MESSAGE_MAP(CMyDlg, CDialog)
//{{AFX_MSG_MAP(CMyDlg)
ON_WM_SYSCOMMAND()
ON_WM_PAINT()
ON_WM_QUERYDRAGICON()
ON_BN_CLICKED(IDC_FILE_OPEN, OnFileOpen)
ON_WM_TIMER()
ON_WM_CANCELMODE()
//}}AFX_MSG_MAP
END_MESSAGE_MAP()
/////////////////////////////////////////////////////////////////////////////
// CMyDlg message handlers
BOOL CMyDlg::OnInitDialog()
{
CDialog::OnInitDialog();
// Add "About..." menu item to system menu.
// IDM_ABOUTBOX must be in the system command range.
ASSERT((IDM_ABOUTBOX & 0xFFF0) == IDM_ABOUTBOX);
ASSERT(IDM_ABOUTBOX < 0xF000);
CMenu* pSysMenu = GetSystemMenu(FALSE);
if (pSysMenu != NULL)
{
CString strAboutMenu;
strAboutMenu.LoadString(IDS_ABOUTBOX);
if (!strAboutMenu.IsEmpty())
{
pSysMenu->AppendMenu(MF_SEPARATOR);
pSysMenu->AppendMenu(MF_STRING, IDM_ABOUTBOX, strAboutMenu);
}
}
// Set the icon for this dialog. The framework does this automatically
// when the application's main window is not a dialog
SetIcon(m_hIcon, TRUE); // Set big icon
SetIcon(m_hIcon, FALSE); // Set small icon
// TODO: Add extra initialization here
return TRUE; // return TRUE unless you set the focus to a control
}
void CMyDlg::OnSysCommand(UINT nID, LPARAM lParam)
{
if ((nID & 0xFFF0) == IDM_ABOUTBOX)
{
CAboutDlg dlgAbout;
dlgAbout.DoModal();
}
else
{
CDialog::OnSysCommand(nID, lParam);
}
}
// If you add a minimize button to your dialog, you will need the code below
// to draw the icon. For MFC applications using the document/view model,
// this is automatically done for you by the framework.
void CMyDlg::OnPaint()
{
if (IsIconic())
{
CPaintDC dc(this); // device context for painting
SendMessage(WM_ICONERASEBKGND, (WPARAM) dc.GetSafeHdc(), 0);
// Center icon in client rectangle
int cxIcon = GetSystemMetrics(SM_CXICON);
int cyIcon = GetSystemMetrics(SM_CYICON);
CRect rect;
GetClientRect(&rect);
int x = (rect.Width() - cxIcon + 1) / 2;
int y = (rect.Height() - cyIcon + 1) / 2;
// Draw the icon
dc.DrawIcon(x, y, m_hIcon);
}
else
{
CDialog::OnPaint();
}
}
// The system calls this to obtain the cursor to display while the user drags
// the minimized window.
HCURSOR CMyDlg::OnQueryDragIcon()
{
return (HCURSOR) m_hIcon;
}
void CMyDlg::OnFileOpen()
{
// TODO: Add your control notification handler code here
//打开摄像头，指定摄像头0开始，参数2指示是否自动弹出摄像头属性页。
if(!camera.OpenCamera(0)) //false不弹出属性窗，用代码制定宽和高
{
fprintf(stderr, "Can not open camera 0.\n");//不成功，if(!0)，执行代码
//return -1;
}
SetTimer(1,40,NULL); //每隔一段时间读出一帧视频图像
}
void CMyDlg::OnTimer(UINT nIDEvent)
{
// TODO: Add your message handler code here and/or call default
pFrame = camera.QueryFrame(); //抓取一帧
ShowPicture(IDC_srcp, pFrame); //显示图像
CDialog::OnTimer(nIDEvent);
}
void CMyDlg::ShowPicture(int nID, IplImage *Image) //显示图像函数
{
CDC *pDC = GetDlgItem(nID)->GetDC();//根据ID获得窗口指针再获取与该窗口关联的上下文指针
HDC hdc= pDC->GetSafeHdc(); // 获取设备上下文句柄
CRect rect; // 矩形类
GetDlgItem(nID)->GetClientRect(&rect); // 获取box1客户区
CvvImage cimg; //
cimg.CopyOf(Image,1); //参数1代表通道数，故此ShowPicture(int nID, IplImage *Image)函数只能显示单通道图像
cimg.DrawToHDC(hdc,&rect); //输出图像
ReleaseDC( pDC );
cimg.Destroy(); //销毁
}
void CMyDlg::OnCancelMode()
{
CDialog::OnCancelMode();
// TODO: Add your message handler code here
}
void CMyDlg::OnOK()
{
// TODO: Add extra validation here
camera.CloseCamera();
CDialog::OnOK();
}
头文件
// 行人检测Dlg.h : header file
//
#include "cv.h"
#include "highgui.h"
#include "camerads.h"
#if !defined(AFX_DLG_H__A2371946_D45A_470D_A282_28670F9555E9__INCLUDED_)
#define AFX_DLG_H__A2371946_D45A_470D_A282_28670F9555E9__INCLUDED_
#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000
/////////////////////////////////////////////////////////////////////////////
// CMyDlg dialog
class CMyDlg : public CDialog
{
// Construction
public:
void ShowPicture(int nID, IplImage *Image);
CCameraDS camera;
//声明IplImage指针
IplImage* pFrame ;
CMyDlg(CWnd* pParent = NULL); // standard constructor
// Dialog Data
//{{AFX_DATA(CMyDlg)
enum { IDD = IDD_MY_DIALOG };
// NOTE: the ClassWizard will add data members here
//}}AFX_DATA
// ClassWizard generated virtual function overrides
//{{AFX_VIRTUAL(CMyDlg)
protected:
virtual void DoDataExchange(CDataExchange* pDX); // DDX/DDV support
//}}AFX_VIRTUAL
// Implementation
protected:
HICON m_hIcon;
// Generated message map functions
//{{AFX_MSG(CMyDlg)
virtual BOOL OnInitDialog();
afx_msg void OnSysCommand(UINT nID, LPARAM lParam);
afx_msg void OnPaint();
afx_msg HCURSOR OnQueryDragIcon();
afx_msg void OnFileOpen();
afx_msg void OnTimer(UINT nIDEvent);
afx_msg void OnCancelMode();
virtual void OnOK();
//}}AFX_MSG
DECLARE_MESSAGE_MAP()
};
//{{AFX_INSERT_LOCATION}}
// Microsoft Visual C++ will insert additional declarations immediately before the previous line.
#endif // !defined(AFX_DLG_H__A2371946_D45A_470D_A282_28670F9555E9__INCLUDED_)