MFC中打开任意图像并在picture control控件中显示Mat对象

      最近在使用OpenCV制作车牌识别系统，我选择了使用MFC制作界面。
      界面设想是点击“打开图片”去选择任意文件夹（英文名）中的图片，然后将图片显示在picture control控件中。难点就是将Mat类型的图片显示在图形控件中。

---

为“打开图像”这一button按钮添加单击事件：

    Mat src;
    char path1[100] ;
    CString filter;  
    CString path;
    filter = "All Files (*.*)|*.*|JPGtu图片(*.jpg)|*.jpg|BMP图像(*.bmp)|*.bmp|PNG图片(*.png)|*.png||";  
    CFileDialog dlg(TRUE, NULL, NULL, OFN_HIDEREADONLY, filter);  
    if (dlg.DoModal() != IDOK)  
    {  
        MessageBoxA(NULL, "does not chose image", "ss", IDOK);  
        return;  
    }  
    path = dlg.GetPathName();  
    path.Replace(_T("\\"), _T("\\\\"));//转移字符的转换       
    memset(path1, 0, sizeof(path1));  
    int k = path.GetAllocLength();   
    for (int i = 0; path[i] != 0; i++)  
    {  
        path1[i] = path[i];  
    }  

    src = imread(path1); 
    if (!src.data)  
    {  
        MessageBoxA(NULL,"could not load picture","ss",IDOK);  
        return;  
    }

实现效果：

---

添加一个函数用于向图像控件中绘制图片：

//把图像显示在 MFC图片控件里
void CLicensePlateRecognitionDlg::DrawPicToHDC(IplImage *img, UINT ID)
{

    CDC *pDC = GetDlgItem(ID)->GetDC();
    HDC hDC = pDC->GetSafeHdc();
    CRect rect;
    GetDlgItem(ID)->GetClientRect(&rect);
    CvvImage cimg;

    cimg.CopyOf(img,3);
    cimg.DrawToHDC(hDC,&rect);

    ReleaseDC(pDC);
}

注意：CvvImage在OpenCV2.2后就没有了，所以这个版本后面的还有加上这个类

具体添加方法就是自己在项目中新建CvvImage.h和CvvImage.cpp文件并向其中加入代码：
CvvImage.h

#pragma once
#ifndef CVVIMAGE_CLASS_DEF
#define CVVIMAGE_CLASS_DEF
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/core/core.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/imgproc/imgproc_c.h"

class  CvvImage
{
public:
 CvvImage();
 virtual ~CvvImage();

 virtual bool  Create( int width, int height, int bits_per_pixel, int image_origin = 0 );

 virtual bool  Load( const char* filename, int desired_color = 1 );

 virtual bool  LoadRect( const char* filename,
  int desired_color, CvRect r );
#if defined WIN32 || defined _WIN32
 virtual bool  LoadRect( const char* filename,
  int desired_color, RECT r )
 {
  return LoadRect( filename, desired_color,
   cvRect( r.left, r.top, r.right - r.left, r.bottom - r.top ));
 }
#endif

 virtual bool  Save( const char* filename );

 virtual void  CopyOf( CvvImage& image, int desired_color = -1 );
 virtual void  CopyOf( IplImage* img, int desired_color = -1 );
 IplImage* GetImage() { return m_img; };
 virtual void  Destroy(void);

 int Width() { return !m_img ? 0 : !m_img->roi ? m_img->width : m_img->roi->width; };
 int Height() { return !m_img ? 0 : !m_img->roi ? m_img->height : m_img->roi->height;};
 int Bpp() { return m_img ? (m_img->depth & 255)*m_img->nChannels : 0; };
 virtual void  Fill( int color );

 virtual void  Show( const char* window );
#if defined WIN32 || defined _WIN32

 virtual void  Show( HDC dc, int x, int y, int width, int height,
  int from_x = 0, int from_y = 0 );

 virtual void  DrawToHDC( HDC hDCDst, RECT* pDstRect );
#endif
protected:
 IplImage*  m_img;
};
typedef CvvImage CImage;
#endif

CvvImage.cpp:

#include "StdAfx.h"
#include "CvvImage.h"

CV_INLINE RECT NormalizeRect( RECT r );
CV_INLINE RECT NormalizeRect( RECT r )
{
 int t;
 if( r.left > r.right )
 {
  t = r.left;
  r.left = r.right;
  r.right = t;
 }
 if( r.top > r.bottom )
 {
  t = r.top;
  r.top = r.bottom;
  r.bottom = t;
 }
 return r;
}
CV_INLINE CvRect RectToCvRect( RECT sr );
CV_INLINE CvRect RectToCvRect( RECT sr )
{
 sr = NormalizeRect( sr );
 return cvRect( sr.left, sr.top, sr.right - sr.left, sr.bottom - sr.top );
}
CV_INLINE RECT CvRectToRect( CvRect sr );
CV_INLINE RECT CvRectToRect( CvRect sr )
{
 RECT dr;
 dr.left = sr.x;
 dr.top = sr.y;
 dr.right = sr.x + sr.width;
 dr.bottom = sr.y + sr.height;
 return dr;
}
CV_INLINE IplROI RectToROI( RECT r );
CV_INLINE IplROI RectToROI( RECT r )
{
 IplROI roi;
 r = NormalizeRect( r );
 roi.xOffset = r.left;
 roi.yOffset = r.top;
 roi.width = r.right - r.left;
 roi.height = r.bottom - r.top;
 roi.coi = 0;
 return roi;
}
void  FillBitmapInfo( BITMAPINFO*bmi, int width, int height, int bpp, int origin )
{
 assert( bmi && width >= 0 && height >= 0 &&(bpp == 8 || bpp == 24 || bpp == 32));
 BITMAPINFOHEADER* bmih =&(bmi->bmiHeader);
 memset( bmih, 0, sizeof(*bmih));
 bmih->biSize = sizeof(BITMAPINFOHEADER);
 bmih->biWidth = width;
 bmih->biHeight = origin ? abs(height) : -abs(height);
 bmih->biPlanes = 1;
 bmih->biBitCount = (unsigned short)bpp;
 bmih->biCompression = BI_RGB;
 if( bpp == 8 )
 {
  RGBQUAD* palette = bmi->bmiColors;
  int i;
  for( i = 0; i < 256; i++ )
  {
   palette[i].rgbBlue = palette[i].rgbGreen = palette[i].rgbRed= (BYTE)i;
   palette[i].rgbReserved = 0;
  }
 }
}
CvvImage::CvvImage()
{
 m_img = 0;
}
void CvvImage::Destroy()
{
 cvReleaseImage( &m_img );
}
CvvImage::~CvvImage()
{
 Destroy();
}
bool  CvvImage::Create( int w,int h, int bpp, int origin )
{
 const unsigned max_img_size = 10000;
 if( (bpp != 8 && bpp != 24&& bpp != 32) ||
  (unsigned)w >=  max_img_size || (unsigned)h >=max_img_size ||
  (origin != IPL_ORIGIN_TL && origin != IPL_ORIGIN_BL))
 {
  assert(0); // most probably, it is a programming error
  return false;
 }
 if( !m_img || Bpp() != bpp ||m_img->width != w || m_img->height != h )
 {
  if( m_img && m_img->nSize == sizeof(IplImage))
   Destroy();

  m_img = cvCreateImage( cvSize( w, h ), IPL_DEPTH_8U, bpp/8 );
 }
 if( m_img )
  m_img->origin = origin == 0 ? IPL_ORIGIN_TL : IPL_ORIGIN_BL;
 return m_img != 0;
}
void  CvvImage::CopyOf(CvvImage& image, int desired_color )
{
 IplImage* img = image.GetImage();
 if( img )
 {
  CopyOf( img, desired_color );
 }
}

#define HG_IS_IMAGE(img)                                                  \
 ((img) != 0 && ((const IplImage*)(img))->nSize ==sizeof(IplImage) && \
 ((IplImage*)img)->imageData != 0)

void  CvvImage::CopyOf( IplImage* img, int desired_color )
{
 if( HG_IS_IMAGE(img) )
 {
  int color = desired_color;
  CvSize size = cvGetSize( img );
  if( color < 0 )
   color = img->nChannels > 1;
  if( Create( size.width,size.height,
   (!color ? 1 : img->nChannels > 1 ? img->nChannels :3)*8,
   img->origin ))
  {
   cvConvertImage( img, m_img, 0 );
  }
 }
}

bool  CvvImage::Load( const char* filename, int desired_color )
{
 IplImage* img = cvLoadImage( filename, desired_color );
 if( !img )
  return false;
 CopyOf( img, desired_color );
 cvReleaseImage( &img );
 return true;
}

bool  CvvImage::LoadRect( const char* filename,
       int desired_color, CvRect r )
{
 if( r.width < 0 || r.height < 0 ) return false;
 IplImage* img = cvLoadImage(filename, desired_color );
 if( !img )
  return false;
 if( r.width == 0 || r.height == 0 )
 {
  r.width = img->width;
  r.height = img->height;
  r.x = r.y = 0;
 }
 if( r.x > img->width || r.y> img->height ||
  r.x + r.width < 0 || r.y + r.height < 0 )
 {
  cvReleaseImage( &img );
  return false;
 }

 if( r.x < 0 )
 {
  r.width += r.x;
  r.x = 0;
 }
 if( r.y < 0 )
 {
  r.height += r.y;
  r.y = 0;
 }
 if( r.x + r.width > img->width)
  r.width = img->width - r.x;
 if( r.y + r.height >img->height )
  r.height = img->height - r.y;
 cvSetImageROI( img, r );
 CopyOf( img, desired_color );
 cvReleaseImage( &img );
 return true;
}

bool  CvvImage::Save( const char* filename )
{
 if( !m_img )
  return false;
 cvSaveImage( filename, m_img );
 return true;
}

void  CvvImage::Show( const char* window )
{
 if( m_img )
  cvShowImage( window, m_img );
}

void  CvvImage::Show( HDC dc, int x, int y, int w, int h, int from_x,int from_y )
{
 if( m_img && m_img->depth == IPL_DEPTH_8U )
 {
  uchar buffer[sizeof(BITMAPINFOHEADER) + 1024];
  BITMAPINFO* bmi = (BITMAPINFO*)buffer;
  int bmp_w = m_img->width, bmp_h = m_img->height;
  FillBitmapInfo( bmi, bmp_w,bmp_h, Bpp(), m_img->origin );
  from_x = MIN( MAX( from_x, 0 ),bmp_w - 1 );
  from_y = MIN( MAX( from_y, 0 ), bmp_h - 1 );
  int sw = MAX( MIN( bmp_w -from_x, w ), 0 );
  int sh = MAX( MIN( bmp_h - from_y, h ), 0 );
  SetDIBitsToDevice(
   dc, x, y, sw, sh, from_x, from_y, from_y, sh,
   m_img->imageData + from_y*m_img->widthStep,
   bmi, DIB_RGB_COLORS );
 }
}

void  CvvImage::DrawToHDC( HDC hDCDst, RECT* pDstRect )
{
 if( pDstRect && m_img && m_img->depth == IPL_DEPTH_8U&& m_img->imageData )
 {
  uchar buffer[sizeof(BITMAPINFOHEADER) + 1024];
  BITMAPINFO* bmi = (BITMAPINFO*)buffer;
  int bmp_w = m_img->width, bmp_h = m_img->height;
  CvRect roi = cvGetImageROI(m_img );
  CvRect dst = RectToCvRect( *pDstRect );
  if( roi.width == dst.width&& roi.height == dst.height )
  {
   Show( hDCDst, dst.x, dst.y, dst.width, dst.height, roi.x,roi.y );
   return;
  }
  if( roi.width > dst.width )
  {
   SetStretchBltMode(
    hDCDst,           //handle to device context
    HALFTONE );
  }
  else
  {
   SetStretchBltMode(
    hDCDst,           //handle to device context
    COLORONCOLOR );
  }
  FillBitmapInfo( bmi, bmp_w,bmp_h, Bpp(), m_img->origin );
  ::StretchDIBits(
   hDCDst,
   dst.x, dst.y, dst.width, dst.height,
   roi.x, roi.y, roi.width, roi.height,
   m_img->imageData, bmi, DIB_RGB_COLORS, SRCCOPY );
 }
}

void  CvvImage::Fill( int color )
{
 cvSet( m_img,cvScalar(color&255,(color>>8)&255,(color>>16)&255,(color>>24)&255));
}

我们发现在绘制图片的那个函数中传入的参数是IplImage*，所以我们要将Mat->IplImage,很简单：IplImage img = src;

IplImage img = src;
DrawPicToHDC(&img,IDC_SHOWPIC);//转换后直接调用就OK了！

最终效果：