在图像处理时经常会用到从摄像头读取图像。OPENCV有提供的方法来实现，非常简单，不用多说。而使用VC++则没有那么容易，下面介绍使用CImage和DirectShow读取摄像头图像，并显示的对话框中。
我用的开发工具是VS2010。
源代码下载，使用VS2010编译通过。
http://download.csdn.net/detail/sdlypyzq/4087013
一、创建一个MFC对话框程序，工程起名为CameraVCTest。
二、删除无用的控件和按钮。添加一个图片控件，ID为IDC_PICTURE，并为其添加CStatic
类型变量m_picture。添加四个按钮，名称分别为预览，拍照，保存，关闭。ID分别为IDC_VIEW,IDC_TAKEPHOTO,IDC_SAVE,IDC_CLOSE。分别为其添加变量m_view,m_takePhoto,m_save,m_close。双击四个按钮，生成四个响应函数。
三、将DirectShow文件夹和CameraDS类的头文件和源文件拷贝到项目源文件夹下。并在项目属性VC++ Directories 添加include Directories，“.\DirectShow”。在Solution Exlporer添加上CameraDS类的头文件和源文件。
四、在CCameraVCTestDlg 类的头文件中，添加
#include "CameraDS.h" #include <vector> using namespace std;
添加公共变量和方法
vector<CCameraDS> cameralist;
CImage *m_pImage;
void ShowPicture(CImage *img,CStatic *pic);
void SaveCard(CImage *img);
int m_cam_count;
bool isBreak;
CString m_savePath;
CString savePath;
int m_saveIndex;
int m_fileCount;
在源文件的初始化函数里添加：
m_cam_count = CCameraDS::CameraCount();
cameralist.resize(m_cam_count);
if(! cameralist[m_cam_count-1].OpenCamera(m_cam_count-1, false, 640,480))
{
return FALSE;
}
this->isBreak = false;
this->isSave = false;
this->m_view.EnableWindow(TRUE);
this->m_takePhoto.EnableWindow(FALSE);
this->m_save.EnableWindow(FALSE);
添加如下函数
void DoEvents1()
{
MSG msg;
if (::PeekMessage(&msg,NULL,0,0,PM_REMOVE))
{
::TranslateMessage(&msg);
::DispatchMessage(&msg);
}
}
void CCameraVCTestDlg::OnBnClickedView()
{
// TODO: Add your control notification handler code here
this->isBreak = false;
this->m_view.EnableWindow(FALSE);
this->m_takePhoto.EnableWindow(TRUE);
this->m_save.EnableWindow(FALSE);
if(m_cam_count==0)
{
return ;
}//CImage imgShow;
//imgShow.Create(this->MAX_WIDTH,this->MAX_HEIGHT,24);
while(1)
{
DoEvents1();
if(isBreak)
{
break;
}
this->m_pImage = cameralist[m_cam_count-1].QueryFrame2();
this->ShowPicture(m_pImage,&this->m_picture);
//if(m_fileCount == 100)
//{
// this->isBreak = true;
// this->m_bnInit.EnableWindow(TRUE);
// this->m_bnTake.EnableWindow(FALSE);
// this->m_bnSave.EnableWindow(TRUE);
// break;
//}
if(isSave)
{
if(this->m_fileCount<100)
{
//this->m_ctrlProg.SetPos(m_fileCount);
CString path;
path.Format(L"%s\\%d.jpg",savePath,m_fileCount+m_saveIndex);
this->m_pImage->Save(path);
m_fileCount++;
}
else
{
isSave = false;
this->m_view.EnableWindow(FALSE);
this->m_takePhoto.EnableWindow(TRUE);
//this->m_save.EnableWindow(TRUE);
}
}
Sleep(150);
}
}
添加视频帧显示函数
void CCameraVCTestDlg::ShowPicture(CImage *img,CStatic *pic)
{
if(img==NULL)
{
return ;
}
int width = img->GetWidth();
int height = img->GetHeight();
CRect picRect;
this->m_picture.GetClientRect(&picRect);
CRect rt(picRect);
CDC* dc = this->m_picture.GetDC();
CBrush *pBrush = CBrush::FromHandle((HBRUSH)GetStockObject(WHITE_BRUSH));
//dc->FillRect(rt, pBrush);
if(picRect.Height()*width > height*picRect.Width())
{
CPoint p1(0,(picRect.Height()-(picRect.Width()*height/width))/2);
CPoint p2(picRect.Width(),(picRect.Height() - p1.y));
rt.SetRect(p1,p2);
}
else
{
CPoint p1((picRect.Width()-(picRect.Height()*width/height))/2,0);
CPoint p2(picRect.Width()-p1.x,picRect.Height());
rt.SetRect(p1,p2);
}
// }
// this->ShowMouseCursor(CursorTag);
::SetStretchBltMode(dc->m_hDC,HALFTONE);
img->Draw(dc->m_hDC, rt);
}
添加关闭程序
void CCameraVCTestDlg::OnBnClickedClose()
{
this->isBreak = true;
this->OnClose();
}
好了，现在对话框上，点击预览按钮，就可以打开摄像头了，若还需要什么功能自己添加吧，如有问题，可以一起交流。欢迎不吝赐教。
Camera.h
1 #ifndef POINTER_64 2 3 4 #if !defined(_MAC) && (defined(_M_MRX000) || defined(_M_AMD64) || defined(_M_IA64)) && (_MSC_VER >= 1100) && !(defined(MIDL_PASS) || defined(RC_INVOKED)) 5 #define POINTER_64 __ptr64 6 typedef unsigned __int64 POINTER_64_INT; 7 #if defined(_WIN64) 8 #define POINTER_32 __ptr32 9 #else 10 #define POINTER_32 11 #endif 12 #else 13 #if defined(_MAC) && defined(_MAC_INT_64) 14 #define POINTER_64 __ptr64 15 typedef unsigned __int64 POINTER_64_INT; 16 #else 17 #if (_MSC_VER >= 1300) && !(defined(MIDL_PASS) || defined(RC_INVOKED)) 18 #define POINTER_64 __ptr64 19 #else 20 #define POINTER_64 21 #endif 22 typedef unsigned long POINTER_64_INT; 23 #endif 24 #define POINTER_32 25 #endif 26 27 #endif 28 29 30 31 32 33 #ifndef CCAMERA_H 34 #define CCAMERA_H 35 36 #define WIN32_LEAN_AND_MEAN 37 38 #include <atlbase.h> 39 #include "qedit.h" 40 #include "dshow.h" 41 #include <windows.h> 42 //#include "cv.h" 43 44 //#include <cxcore.h> 45 46 #define MYFREEMEDIATYPE(mt) {if ((mt).cbFormat != 0) \ 47 {CoTaskMemFree((PVOID)(mt).pbFormat); \ 48 (mt).cbFormat =0; \ 49 (mt).pbFormat = NULL; \ 50 } \ 51 if ((mt).pUnk != NULL) \ 52 { \ 53 (mt).pUnk->Release(); \ 54 (mt).pUnk = NULL; \ 55 }} 56 57 58 class CCameraDS 59 { 60 private: 61 // IplImage * m_pFrame; 62 CImage m_image; 63 bool m_bConnected; 64 int m_nWidth; 65 int m_nHeight; 66 bool m_bLock; 67 bool m_bChanged; 68 long m_nBufferSize; 69 70 CComPtr<IGraphBuilder> m_pGraph; 71 CComPtr<IBaseFilter> m_pDeviceFilter; 72 CComPtr<IMediaControl> m_pMediaControl; 73 CComPtr<IBaseFilter> m_pSampleGrabberFilter; 74 CComPtr<ISampleGrabber> m_pSampleGrabber; 75 CComPtr<IPin> m_pGrabberInput; 76 CComPtr<IPin> m_pGrabberOutput; 77 CComPtr<IPin> m_pCameraOutput; 78 CComPtr<IMediaEvent> m_pMediaEvent; 79 CComPtr<IBaseFilter> m_pNullFilter; 80 CComPtr<IPin> m_pNullInputPin; 81 82 private: 83 bool BindFilter(int nCamIDX, IBaseFilter **pFilter); 84 void SetCrossBar(); 85 86 public: 87 CCameraDS(); 88 virtual~CCameraDS(); 89 90 //打开摄像头，nCamID指定打开哪个摄像头，取值可以为0,1,2,... 91 //bDisplayProperties指示是否自动弹出摄像头属性页 92 //nWidth和nHeight设置的摄像头的宽和高，如果摄像头不支持所设定的宽度和高度，则返回false 93 bool CCameraDS::OpenCamera(int nCamID, bool bDisplayProperties=true, int nWidth =320, int nHeight =240); 94 95 //关闭摄像头，析构函数会自动调用这个函数 96 void CloseCamera(); 97 98 //返回摄像头的数目 99 //可以不用创建CCameraDS实例，采用int c=CCameraDS::CameraCount();得到结果。100 staticint CameraCount(); 101 102 //根据摄像头的编号返回摄像头的名字103 //nCamID: 摄像头编号104 //sName: 用于存放摄像头名字的数组105 //nBufferSize: sName的大小106 //可以不用创建CCameraDS实例，采用CCameraDS::CameraName();得到结果。107 staticint CCameraDS::CameraName(int nCamID, char* sName, int nBufferSize);108 109 //返回图像宽度110 int GetWidth(){return m_nWidth;} 111 112 //返回图像高度113 int GetHeight(){return m_nHeight;}114 115 //抓取一帧，返回的IplImage不可手动释放！116 //返回图像数据的为RGB模式的Top-down(第一个字节为左上角像素)，即IplImage::origin=0(IPL_ORIGIN_TL)117 // IplImage * QueryFrame();118 CImage* QueryFrame2(); 119 };120 121 #endif
camera.cpp
#include "stdafx.h"#include "CameraDS.h"#pragma comment(lib,"Strmiids.lib") //////////////////////////////////////////////////////////////////////// Construction/Destruction//////////////////////////////////////////////////////////////////////CCameraDS::CCameraDS(){ m_bConnected =false; m_nWidth =0; m_nHeight =0; m_bLock =false; m_bChanged =false;// m_pFrame = NULL; m_nBufferSize =0; m_pNullFilter = NULL; m_pMediaEvent = NULL; m_pSampleGrabberFilter = NULL; m_pGraph = NULL; CoInitialize(NULL);}CCameraDS::~CCameraDS(){ CloseCamera(); CoUninitialize();}void CCameraDS::CloseCamera(){ if(m_bConnected) m_pMediaControl->Stop(); m_pGraph = NULL; m_pDeviceFilter = NULL; m_pMediaControl = NULL; m_pSampleGrabberFilter = NULL; m_pSampleGrabber = NULL; m_pGrabberInput = NULL; m_pGrabberOutput = NULL; m_pCameraOutput = NULL; m_pMediaEvent = NULL; m_pNullFilter = NULL; m_pNullInputPin = NULL; //if (m_pFrame) // cvReleaseImage(&m_pFrame);if(!this->m_image.IsNull()) { this->m_image.Destroy(); } m_bConnected =false; m_nWidth =0; m_nHeight =0; m_bLock =false; m_bChanged =false; m_nBufferSize =0;}bool CCameraDS::OpenCamera(int nCamID, bool bDisplayProperties, int nWidth, int nHeight){ HRESULT hr = S_OK; CoInitialize(NULL); // Create the Filter Graph Manager. hr = CoCreateInstance(CLSID_FilterGraph, NULL, CLSCTX_INPROC, IID_IGraphBuilder, (void**)&m_pGraph); hr = CoCreateInstance(CLSID_SampleGrabber, NULL, CLSCTX_INPROC_SERVER, IID_IBaseFilter, (LPVOID *)&m_pSampleGrabberFilter); hr = m_pGraph->QueryInterface(IID_IMediaControl, (void**) &m_pMediaControl); hr = m_pGraph->QueryInterface(IID_IMediaEvent, (void**) &m_pMediaEvent); hr = CoCreateInstance(CLSID_NullRenderer, NULL, CLSCTX_INPROC_SERVER, IID_IBaseFilter, (LPVOID*) &m_pNullFilter); hr = m_pGraph->AddFilter(m_pNullFilter, L"NullRenderer"); hr = m_pSampleGrabberFilter->QueryInterface(IID_ISampleGrabber, (void**)&m_pSampleGrabber); AM_MEDIA_TYPE mt; ZeroMemory(&mt, sizeof(AM_MEDIA_TYPE)); mt.majortype = MEDIATYPE_Video; mt.subtype = MEDIASUBTYPE_RGB24; mt.formattype = FORMAT_VideoInfo; hr = m_pSampleGrabber->SetMediaType(&mt); MYFREEMEDIATYPE(mt); m_pGraph->AddFilter(m_pSampleGrabberFilter, L"Grabber"); // Bind Device Filter. We know the device because the id was passed in BindFilter(nCamID, &m_pDeviceFilter); m_pGraph->AddFilter(m_pDeviceFilter, NULL); CComPtr<IEnumPins> pEnum; m_pDeviceFilter->EnumPins(&pEnum); hr = pEnum->Reset(); hr = pEnum->Next(1, &m_pCameraOutput, NULL); pEnum = NULL; m_pSampleGrabberFilter->EnumPins(&pEnum); pEnum->Reset(); hr = pEnum->Next(1, &m_pGrabberInput, NULL); pEnum = NULL; m_pSampleGrabberFilter->EnumPins(&pEnum); pEnum->Reset(); pEnum->Skip(1); hr = pEnum->Next(1, &m_pGrabberOutput, NULL); pEnum = NULL; m_pNullFilter->EnumPins(&pEnum); pEnum->Reset(); hr = pEnum->Next(1, &m_pNullInputPin, NULL); //SetCrossBar(); if (bDisplayProperties) { CComPtr<ISpecifyPropertyPages> pPages; HRESULT hr = m_pCameraOutput->QueryInterface(IID_ISpecifyPropertyPages, (void**)&pPages); if (SUCCEEDED(hr)) { PIN_INFO PinInfo; m_pCameraOutput->QueryPinInfo(&PinInfo); CAUUID caGUID; pPages->GetPages(&caGUID); OleCreatePropertyFrame(NULL, 0, 0, L"Property Sheet", 1, (IUnknown **)&(m_pCameraOutput.p), caGUID.cElems, caGUID.pElems, 0, 0, NULL); CoTaskMemFree(caGUID.pElems); PinInfo.pFilter->Release(); } pPages = NULL; } else { //////////////////////////////////////////////////////////////////////////////// 加入由 lWidth和lHeight设置的摄像头的宽和高 的功能，默认320*240 // by flymanbox @2009-01-24//////////////////////////////////////////////////////////////////////////////int _Width = nWidth, _Height = nHeight; IAMStreamConfig* iconfig; iconfig = NULL; hr = m_pCameraOutput->QueryInterface(IID_IAMStreamConfig, (void**)&iconfig); AM_MEDIA_TYPE* pmt; if(iconfig->GetFormat(&pmt) !=S_OK) { //printf("GetFormat Failed ! \n");returnfalse; } VIDEOINFOHEADER* phead; if ( pmt->formattype == FORMAT_VideoInfo) { phead=( VIDEOINFOHEADER*)pmt->pbFormat; phead->bmiHeader.biWidth = _Width; phead->bmiHeader.biHeight = _Height; if(( hr=iconfig->SetFormat(pmt)) != S_OK ) { returnfalse; } } iconfig->Release(); iconfig=NULL; MYFREEMEDIATYPE(*pmt); } hr = m_pGraph->Connect(m_pCameraOutput, m_pGrabberInput); hr = m_pGraph->Connect(m_pGrabberOutput, m_pNullInputPin); if (FAILED(hr)) { switch(hr) { case VFW_S_NOPREVIEWPIN : break; case E_FAIL : break; case E_INVALIDARG : break; case E_POINTER : break; } } m_pSampleGrabber->SetBufferSamples(TRUE); m_pSampleGrabber->SetOneShot(TRUE); hr = m_pSampleGrabber->GetConnectedMediaType(&mt); if(FAILED(hr)) returnfalse; VIDEOINFOHEADER *videoHeader; videoHeader = reinterpret_cast<VIDEOINFOHEADER*>(mt.pbFormat); m_nWidth = videoHeader->bmiHeader.biWidth; m_nHeight = videoHeader->bmiHeader.biHeight; m_bConnected =true; pEnum = NULL; returntrue;}
bool CCameraDS::BindFilter(int nCamID, IBaseFilter **pFilter){ if (nCamID <0) returnfalse; // enumerate all video capture devices CComPtr<ICreateDevEnum> pCreateDevEnum; HRESULT hr = CoCreateInstance(CLSID_SystemDeviceEnum, NULL, CLSCTX_INPROC_SERVER, IID_ICreateDevEnum, (void**)&pCreateDevEnum); if (hr != NOERROR) { returnfalse; } CComPtr<IEnumMoniker> pEm; hr = pCreateDevEnum->CreateClassEnumerator(CLSID_VideoInputDeviceCategory, &pEm, 0); if (hr != NOERROR) { returnfalse; } pEm->Reset(); ULONG cFetched; IMoniker *pM; int index =0; while(hr = pEm->Next(1, &pM, &cFetched), hr==S_OK, index <= nCamID) { IPropertyBag *pBag; hr = pM->BindToStorage(0, 0, IID_IPropertyBag, (void**)&pBag); if(SUCCEEDED(hr)) { VARIANT var; var.vt = VT_BSTR; hr = pBag->Read(L"FriendlyName", &var, NULL); if (hr == NOERROR) { if (index == nCamID) { pM->BindToObject(0, 0, IID_IBaseFilter, (void**)pFilter); } SysFreeString(var.bstrVal); } pBag->Release(); } pM->Release(); index++; } pCreateDevEnum = NULL; returntrue;}//将输入crossbar变成PhysConn_Video_Compositevoid CCameraDS::SetCrossBar(){ int i; IAMCrossbar *pXBar1 = NULL; ICaptureGraphBuilder2 *pBuilder = NULL; HRESULT hr = CoCreateInstance(CLSID_CaptureGraphBuilder2, NULL, CLSCTX_INPROC_SERVER, IID_ICaptureGraphBuilder2, (void**)&pBuilder); if (SUCCEEDED(hr)) { hr = pBuilder->SetFiltergraph(m_pGraph); } hr = pBuilder->FindInterface(&LOOK_UPSTREAM_ONLY, NULL, m_pDeviceFilter,IID_IAMCrossbar, (void**)&pXBar1); if (SUCCEEDED(hr)) { long OutputPinCount; long InputPinCount; long PinIndexRelated; long PhysicalType; long inPort =0; long outPort =0; pXBar1->get_PinCounts(&OutputPinCount,&InputPinCount); for( i =0;i<InputPinCount;i++) { pXBar1->get_CrossbarPinInfo(TRUE,i,&PinIndexRelated,&PhysicalType); if(PhysConn_Video_Composite==PhysicalType) { inPort = i; break; } } for( i =0;i<OutputPinCount;i++) { pXBar1->get_CrossbarPinInfo(FALSE,i,&PinIndexRelated,&PhysicalType); if(PhysConn_Video_VideoDecoder==PhysicalType) { outPort = i; break; } } if(S_OK==pXBar1->CanRoute(outPort,inPort)) { pXBar1->Route(outPort,inPort); } pXBar1->Release(); } pBuilder->Release();}/*The returned image can not be released.//*///IplImage* CCameraDS::QueryFrame()//{//// long evCode;// long size = 0;//// m_pMediaControl->Run();// m_pMediaEvent->WaitForCompletion(INFINITE, &evCode);// // m_pSampleGrabber->GetCurrentBuffer(&size, NULL);//////if the buffer size changed// if (size != m_nBufferSize)// {// if (m_pFrame)// cvReleaseImage(&m_pFrame);//// m_nBufferSize = size;// m_pFrame = cvCreateImage(cvSize(m_nWidth, m_nHeight), IPL_DEPTH_8U, 3);// }// if (m_pFrame == NULL) return NULL;// m_pSampleGrabber->GetCurrentBuffer(&m_nBufferSize, (long*)m_pFrame->imageData);// cvFlip(m_pFrame);//// return m_pFrame;//}CImage* CCameraDS::QueryFrame2(){ /*if(!m_image.IsNull()) { m_image.Destroy(); }*/ long evCode; long size =0; m_pMediaControl->Run(); m_pMediaEvent->WaitForCompletion(INFINITE, &evCode); m_pSampleGrabber->GetCurrentBuffer(&size, NULL); //if the buffer size changedif (size != m_nBufferSize) { //if (m_pImage != NULL )//|| !m_pImage->IsNull()) //{ // m_pImage->Destroy(); //} // cvReleaseImage(&m_pFrame); m_nBufferSize = size; //m_pFrame = cvCreateImage(cvSize(m_nWidth, m_nHeight), IPL_DEPTH_8U, 3); m_image.Create(m_nWidth,m_nHeight,24); } //if (m_pFrame == NULL) return NULL;if(m_image.IsNull()) { return0; } byte*q; byte*p =newbyte[m_nWidth*m_nHeight*3]; //m_pSampleGrabber->GetCurrentBuffer(&m_nBufferSize, (long*)m_pFrame->imageData); m_pSampleGrabber->GetCurrentBuffer(&m_nBufferSize, (long*)p);// cvFlip(m_pFrame); //for(int y=0, z=m_nHeight-1; y<m_nHeight,z>=0; y++,z--) { q = (byte*)m_image.GetPixelAddress(0,z); memcpy(q,&p[m_nWidth*3*y],m_nWidth*3); } delete []p; return&m_image;}int CCameraDS::CameraCount(){ int count =0; CoInitialize(NULL); // enumerate all video capture devices CComPtr<ICreateDevEnum> pCreateDevEnum; HRESULT hr = CoCreateInstance(CLSID_SystemDeviceEnum, NULL, CLSCTX_INPROC_SERVER, IID_ICreateDevEnum, (void**)&pCreateDevEnum); CComPtr<IEnumMoniker> pEm; hr = pCreateDevEnum->CreateClassEnumerator(CLSID_VideoInputDeviceCategory, &pEm, 0); if (hr != NOERROR) { return count; } pEm->Reset(); ULONG cFetched; IMoniker *pM; while(hr = pEm->Next(1, &pM, &cFetched), hr==S_OK) { count++; } pCreateDevEnum = NULL; pEm = NULL; return count;}int CCameraDS::CameraName(int nCamID, char* sName, int nBufferSize){ int count =0; CoInitialize(NULL); // enumerate all video capture devices CComPtr<ICreateDevEnum> pCreateDevEnum; HRESULT hr = CoCreateInstance(CLSID_SystemDeviceEnum, NULL, CLSCTX_INPROC_SERVER, IID_ICreateDevEnum, (void**)&pCreateDevEnum); CComPtr<IEnumMoniker> pEm; hr = pCreateDevEnum->CreateClassEnumerator(CLSID_VideoInputDeviceCategory, &pEm, 0); if (hr != NOERROR) return0; pEm->Reset(); ULONG cFetched; IMoniker *pM; while(hr = pEm->Next(1, &pM, &cFetched), hr==S_OK) { if (count == nCamID) { IPropertyBag *pBag=0; hr = pM->BindToStorage(0, 0, IID_IPropertyBag, (void**)&pBag); if(SUCCEEDED(hr)) { VARIANT var; var.vt = VT_BSTR; hr = pBag->Read(L"FriendlyName", &var, NULL); //还有其他属性,像描述信息等等...if(hr == NOERROR) { //获取设备名称 WideCharToMultiByte(CP_ACP,0,var.bstrVal,-1,sName, nBufferSize ,"",NULL); SysFreeString(var.bstrVal); } pBag->Release(); } pM->Release(); break; } count++; } pCreateDevEnum = NULL; pEm = NULL; return1;}
来源：https://www.cnblogs.com/sdlypyzq/archive/2011/08/13/CameraVCTest.html