[BCB] WebCam的處理

WebCam的輸入與擷取在BCB實作上算是蠻簡單的，windows的函式庫已經有很完整的範例可以參考，這邊記錄下這次的處理方法

輸入原理:
1. capCreateCaptureWindow 先指定視窗handle給裝置
2. capDriverConnect 連結裝置
3. 設定&拷貝 capDriverGetCaps

	//啟動
	bool __fastcall TForm_main::OpenOCR()
	{
	int i,width=320,height=240;
	bool a = false;
	if(!hCapWnd)
	{ // Form_main->Handle //0
	hCapWnd = capCreateCaptureWindow("My Capture Window", WS_CHILD | WS_VISIBLE,0, 0, 320, 240 ,PanelOCR->Handle, (int)1 );//建立一個擷取視窗
	//以下的For迴圈是為了去連結裝置
	for(i=0;i<10;i++)
	{
	a=capDriverConnect(hCapWnd,i); //連接裝置
	if(a) break;
	}
	//如果沒有啟動成功，則a為false，反之則為true
	if(!a)
	{
	//ShowMessage("Connect Camera Error!!");
	Panel5->Caption="CAM ERR!";
	return false;
	}
	PanelOCR->Width=width;
	PanelOCR->Height=height;
	capOverlay(hCapWnd,true); //開啟覆疊
	//capPreviewScale(hCapWnd,true); //開啟比例
	capPreviewRate(hCapWnd, 1000/10); //每秒10畫格
	capPreview(hCapWnd,true); //開啟預覽
	//capPreview(hCapWnd,false); //關閉預覽
	//20161114++
	CAPDRIVERCAPS *psCaps;
	psCaps= new CAPDRIVERCAPS;
	capDriverGetCaps (hCapWnd,psCaps,sizeof(CAPDRIVERCAPS));
	capOverlay(hCapWnd,true);
	delete psCaps;
	//20161114++
	}
	TimerOCR->Enabled=true;
	return true;
	}
	//---------------------------------------------------------------------------
	//關閉
	bool __fastcall TForm_main::CloseOCR()
	{
	TimerOCR->Enabled=false;
	if(hCapWnd)
	{
	capDriverDisconnect(hCapWnd); //停止裝置
	hCapWnd=NULL;
	}
	return true;
	}
	//---------------------------------------------------------------------------
	//擷取
	void __fastcall TForm_main::GetImageOCR()
	{
	//20161130++
	Graphics::TBitmap*Source=new Graphics::TBitmap();
	Source->PixelFormat = pf24bit; //2009/1/13 add for iroi important
	//開始抓取
	SendMessage(hCapWnd,WM_CAP_GRAB_FRAME,0,0);
	capGrabFrameNoStop(hCapWnd);
	capEditCopy(hCapWnd);
	try
	{
	//用剪貼簿的方式讀取
	if(Clipboard()->HasFormat(CF_BITMAP))Source->LoadFromClipboardFormat(CF_BITMAP,Clipboard()->GetAsHandle(CF_BITMAP),0);
	//務必要設定大小 因為新的攝影機輸入640*480會當掉
	Source->Width=PanelOCR->Width;
	Source->Height=PanelOCR->Height;
	//剪裁成適當尺寸
	BitBlt(Source->Canvas->Handle, 0, 0, PanelOCR->Width, PanelOCR->Height, Source->Canvas->Handle, 0, 0, SRCCOPY);
	//存圖測試
	AnsiString VFilename = "tmp.bmp"; //for store
	Source->SaveToFile(VFilename.c_str());
	//目標顯示
	ImageOCR->Picture->Assign(Source);
	//再放回已剪裁的圖
	Clipboard()->Assign(Source);
	}catch(Exception &E){WriteLog("ERR"+E.Message);}
	delete Source;
	}
	//---------------------------------------------------------------------------

view raw [BCB]WebCamHandle.cpp hosted with ❤ by GitHub

輸出到eVision的結構中使用:

	void __fastcall TForm_Learn::SpeedButton1Click(TObject *Sender)
	{
	TCanvas *csBuf=new TCanvas;
	HDC hDC=GetDC(Form_main->PanelOCR->Handle);
	csBuf->Handle=hDC;
	Graphics::TBitmap*Source=new Graphics::TBitmap();
	Source->Width=Form_main->PanelOCR->Width;
	Source->Height=Form_main->PanelOCR->Height;
	Source->PixelFormat = pf24bit; //2009/1/14 important
	Source->Canvas->CopyRect(Rect(0, 0, Source->Width, Source->Height),csBuf, Rect(0, 0, Form_main->PanelOCR->Width, Form_main->PanelOCR->Height));
	byte* pSrc;
	byte* pDest;
	SrcImg->SetSize(320,240);
	for(int row = 0; row < Source->Height; row++)
	{
	pSrc = (Byte *)Source->ScanLine[row];
	pDest = (Byte *)SrcImg->m_pImagePtr + row * Source->Width * 3;
	CopyMemory(pDest, pSrc, Source->Width * 3);
	}
	//for 灰階影像
	BWSrc.SetSize(320,240);
	BWDst.SetSize(320,240);
	ClrGetComponent(SrcImg,&BWSrc, 1);
	ReleaseDC(0,hDC);
	delete csBuf;
	delete Source;
	RedrawWindow(Handle, NULL, NULL, RDW_INVALIDATE | RDW_UPDATENOW);
	}

view raw [BCB]WebCamHandle2.cpp hosted with ❤ by GitHub