OPENCV的2-10备注

#include "cv.h"
#include "highgui.h"
#include <stdio.h>

// Convert a video to grayscale
// argv[1]: input video file
// argv[2]: name of new output file
//

IplImage* doresize(IplImage* in){
IplImage* out1 = cvCreateImage( 
        cvSize( in->width/2, in->height/2 ),
        in->depth,
        in->nChannels
    );
    return( out1 );
};
IplImage* doPyrDown(
  IplImage* in,
  int       filter = IPL_GAUSSIAN_5x5)
{

    IplImage* out = cvCreateImage( 
        cvSize( in->width/2, in->height/2 ),
        in->depth,
        in->nChannels
    );
    cvPyrDown( in, out );
    return( out );
};
int main( int argc, char* argv[] ) {
    cvNamedWindow( "Example2_10", CV_WINDOW_AUTOSIZE );
    cvNamedWindow( "Log_Polar", CV_WINDOW_AUTOSIZE );
    CvCapture* capture = cvCreateFileCapture(  "D:\\1.wmv" );
    if (!capture){
        return -1;
    }
    IplImage* bgr_frame;IplImage* img_pyr;
    double fps = cvGetCaptureProperty (
        capture,
        CV_CAP_PROP_FPS
    );
	printf("fps=%d\n",(int)fps);

    CvSize size = cvSize(
        (int)cvGetCaptureProperty( capture, CV_CAP_PROP_FRAME_WIDTH),
        (int)cvGetCaptureProperty( capture, CV_CAP_PROP_FRAME_HEIGHT)
    );
    
    printf("frame (w, h) = (%d, %d)\n",size.width,size.height);
    CvVideoWriter* writer = cvCreateVideoWriter(  // On linux Will only work if you've installed ffmpeg development files correctly, 
        "D:\\33.avi",                               // otherwise segmentation fault.  Windows probably better.
        CV_FOURCC('D','X','5','0'),    
        fps,
        size
    );
    IplImage* logpolar_frame = cvCreateImage(
        size,
        IPL_DEPTH_8U,
        3
    );
     IplImage* gray_frame = cvCreateImage(
        size,
        IPL_DEPTH_8U,
        1
    );
    while( (bgr_frame=cvQueryFrame(capture)) != NULL ) {
        cvShowImage( "Example2_10", bgr_frame );
        //cvLogPolar( bgr_frame, logpolar_frame,  //This is just a fun conversion the mimic's the human visual system
        //            cvPoint2D32f(bgr_frame->width/2,
        //            bgr_frame->height/2), 
        //            40, 
        //            CV_INTER_LINEAR+CV_WARP_FILL_OUTLIERS );  //此语句正确

		cvCvtColor(bgr_frame, gray_frame,CV_BGR2GRAY);  //将色彩转换为灰度，必须与上面的IplImage* gray_frame搭配使用才行
		//用上语句转换灰度，则需要将gray_frame通道初始化为1，若为3则发生错误，下句可将gray_frame通道初始化为1为3，因为未指定转换格式CV_BGR2GRAY
		//cvConvertImage(bgr_frame, gray_frame,CV_CVTIMG_FLIP);//图像180度旋转
		/****以上两句程序都是讲图像转换为灰度****/

		img_pyr=doresize(gray_frame); cvResize(gray_frame,img_pyr); 
		//使用cvResize需要先将目标图像初始化好为目标图像的一般即doresize所做的，然后才好将原图像转换为目标图像的一般
		//img_pyr =doPyrDown(gray_frame,IPL_GAUSSIAN_5x5);  //gray_frame =doPyrDown(gray_frame,IPL_GAUSSIAN_5x5);这里必须重新定义指针，直接用这语句不对
        /****以上两句程序都是讲图像缩放为原来的一般****/

       cvShowImage( "Log_Polar", img_pyr );
        //Sigh, on linux, depending on your ffmpeg, this often won't work ...
       cvWriteToAVI( writer, img_pyr );
        char c = cvWaitKey(10);
        if( c == 27 ) break;
    }
    cvReleaseVideoWriter( &writer );
    cvReleaseImage( &img_pyr );           
    cvReleaseCapture( &capture );
}