OpenCV笔记-在MFC中使用OpenCV
目录：
详细内容：
1.在MFC中，OpenCV读取图像，使用win32函数显示图像。
首先是创建位图信息结构：
LPBITMAPINFO CcvMFC_OpenCVDlg::CtreateMapInfo(IplImage* img) { BITMAPINFOHEADER bIH = {40, 1, 1, 1, 8, 0, 0, 0, 0, 0, 0}; LPBITMAPINFO lpBmpInfo; RGBQUAD ColorTab[256]; int width, height, bits, colors; width = img->width; height = img->height; bits = img->depth * img->nChannels; if(bits > 8) colors = 0; else colors = 1 << bits; lpBmpInfo = (LPBITMAPINFO)malloc(40 + colors * 4); bIH.biWidth = width; bIH.biHeight = height; bIH.biBitCount = bits; memcpy(lpBmpInfo, &bIH, 40); if(bits == 8) { for(int i = 0;i < 256; ++i) { ColorTab[i].rgbRed = ColorTab[i].rgbGreen = ColorTab[i].rgbBlue = i; } memcpy(lpBmpInfo->bmiColors, ColorTab, 256 * 4); } return lpBmpInfo; }
然后显示图像：
void CcvMFC_OpenCVDlg::OnBnClickedBtnShow() { /*加载图片*/ IplImage *image = cvLoadImage("E:\\Res\\image\\EW.bmp"); CRect rect; GetClientRect(&rect);/*得到所绘制的DC的大小*/ CvSize size; size.width = rect.Height() * image->width / image->height; size.height = rect.Height(); /*创建对应大小的图像*/ IplImage *dest = cvCreateImage(size, image->depth, image->nChannels); /*图片缩放*/ cvResize(image, dest); /*上下旋转图片*/ char *data = (char*) malloc(dest->widthStep * dest->height); for(int i = 0; i < dest->height; ++i) { char *ptr = dest->imageData + dest->widthStep * (dest->height - i - 1); char *ptr2 = data + dest->widthStep * i; for(int j = 0; j < dest->width * dest->nChannels; ++j) { *(ptr2 + j) = *(ptr + j); } } m_lpBmpInfo = CtreateMapInfo(dest);/*创建位图信息*/ /*绘制位图*/ ::StretchDIBits(GetDC()->m_hDC, 0, 0, size.width, size.height, 0, 0, dest->width, dest->height, data, m_lpBmpInfo, DIB_RGB_COLORS, SRCCOPY); ReleaseMapInfo(m_lpBmpInfo);/*释放位图信息结构*/ free(data); cvReleaseImage(&dest); cvReleaseImage(&image); }
最后注意释放位图信息结构：
void CcvMFC_OpenCVDlg::ReleaseMapInfo(LPBITMAPINFO lpBmpInfo) { if(lpBmpInfo != NULL) free(lpBmpInfo); lpBmpInfo = NULL; }
2.使用CvvImage类读取和显示图像，不过CvvImage类在OpenCV2.2被取消了，得自己添加到自己的工程或者把CvvImage做成lib库供调用。
可以参考：http://www.opencv.org.cn/forum/viewtopic.php?f=1&t=12151&p=44074#p44068
CvvImage类定义：
#pragma once #ifndef CVVIMAGE_CLASS_DEF #define CVVIMAGE_CLASS_DEF #include <opencv.hpp> /* CvvImage class definition */ class CvvImage { public: CvvImage(); virtual ~CvvImage(); /* Create image (BGR or grayscale) */ virtual bool Create( int width, int height, int bits_per_pixel, int image_origin = 0 ); /* Load image from specified file */ virtual bool Load( const char* filename, int desired_color = 1 ); /* Load rectangle from the file */ 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 /* Save entire image to specified file. */ virtual bool Save( const char* filename ); /* Get copy of input image ROI */ 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); /* width and height of ROI */ 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 ); /* draw to highgui window */ virtual void Show( const char* window ); #if defined WIN32 || defined _WIN32 /* draw part of image to the specified DC */ virtual void Show( HDC dc, int x, int y, int width, int height, int from_x = 0, int from_y = 0 ); /* draw the current image ROI to the specified rectangle of the destination DC */ virtual void DrawToHDC( HDC hDCDst, RECT* pDstRect ); #endif protected: IplImage* m_img; }; typedef CvvImage CImage; #endif
CvvImage实现：
#include "stdafx.h" //#include "CvvImage.h" ////////////////////////////////////////////////////////////////////// // Construction/Destruction ////////////////////////////////////////////////////////////////////// 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(); /* prepare IPL header */ 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; } /* truncate r to source image */ 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) ); }
使用CvvImage读取和显示图像：
void CcvMFC_OpenCV2Dlg::OnBnClickedBtnShow() { CvvImage image; image.Load("E:\\Res\\image\\EW.bmp"); RECT rect; GetClientRect(&rect); rect.right = rect.left + (rect.bottom - rect.top) * image.Height() / image.Width(); image.DrawToHDC(GetDC()->m_hDC, &rect); }