OpenCV学习笔记之八(保存视频，录制视频，cvLoadImage的路径)

1.保存视频、录制视频

#include "stdafx.h"
#include <iostream>
#include "cv.h"
#include "highgui.h"
#include "cxcore.h"

int _tmain(int argc, _TCHAR* argv[])
{
IplImage* frame = NULL;
CvCapture* capture = cvCreateCameraCapture(0);
CvVideoWriter* video=NULL;

if(!capture)
{
cout<<"Camera does not work correctly!\n"<<endl;
}
else
{
frame=cvQueryFrame(capture); //首先取得摄像头中的一帧
video=cvCreateVideoWriter("D:\\XXX.avi", CV_FOURCC('X', 'V', 'I', 'D'), 25, cvSize(frame->width,frame->height));
//创建CvVideoWriter对象并分配空间
//保存的文件名为camera.avi，编码要在运行程序时选择，大小就是摄像头视频的大小，帧频率是32
if(video) //如果能创建CvVideoWriter对象则表明成功
{
cout<<"VideoWriter has created."<<endl;
}
cvNamedWindow("Camera Video",1); //新建一个窗口
while(1)
{
if(!cvQueryFrame(capture) )
{	cout<<"do not receive any picture!";
break;
}
else
{
cout<<cvWriteFrame(video,frame)<<endl;
cvShowImage("Camera Video",frame);
if(cvWaitKey(2)>0)
break;
}
}

}

cvReleaseCapture(&capture);
cvDestroyWindow("avi");

return 0;
}

注意，cvWriteFrame();函数只能够把三通道图像保存为视频，对于单通道的图像可以采用复制成三通道图像的方式来保存录制的视频。

int _tmain(int argc, _TCHAR* argv[])
{
IplImage* frame = NULL;
IplImage* frame_single = NULL;
CvCapture* capture = cvCreateCameraCapture(0);
CvVideoWriter* video=NULL;

frame = cvQueryFrame(capture); //首先取得摄像头中的一帧
frame_single = cvCreateImage(cvGetSize(frame),frame->depth,1);
video = cvCreateVideoWriter("D:\\camera_mao_bian_guang.avi", CV_FOURCC('X', 'V', 'I', 'D'),15, cvSize(frame->width,frame->height));
cvNamedWindow("Camera Video",1); //新建一个窗口
while(1)
{
frame = cvQueryFrame(capture);
cvCvtColor(frame,frame_single,CV_BGR2GRAY);
cvMerge(frame_single,frame_single,frame_single,NULL,frame);
cvWriteFrame(video,frame);
cvShowImage("Camera Video",frame_single);
if(cvWaitKey(2)>0)
break;
}

cvReleaseCapture(&capture);
cvDestroyWindow("Camera Video");

return 0;
}

2.以变量方式加载图像路径

char FilePath[100];
sprintf(FilePath,"D:\\PERSONAL\\VC++\\OpenCV\\image\\hyhead4.jpg");
IplImage* src = cvLoadImage(FilePath);

mf_displayCVimage(IDC_PICTURE_HSV,src);

另一种：

char FilePath[100] = {NULL};
CString str_path = NULL;
if(dlg.DoModal()==IDOK)
str_path = dlg.GetPathName();
int len = str_path.GetLength();
for(int i = 0;i<len;i++)
{
FilePath[i] = str_path.GetAt(i);
}

IplImage* src = cvLoadImage(FilePath,0);

注意，cvLoadImage接收的路径只能是char*

char path[] path相当于指针。

3.在MFC中显示图像方法（视频类似）

1.准备头文件 CvvImage.h

#ifndef CVVIMAGE_CLASS_DEF
#define CVVIMAGE_CLASS_DEF

#include <opencv/cv.h>
#include <opencv/highgui.h>

/* 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

2.准备源文件CvvImage.cpp

#include "stdafx.h"//加到工程后这个就要添上
#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) );
}

3.加载1和2以后，图像显示例程

见：VC+MFC 学习笔记之一（截止到2016.4.9）中的第2点。

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