opcv code 4

higui function

http://www.cognotics.com/opencv/docs/1.0/ref/opencvref_highgui.htm#decl_CvCapture
------------------------------------------------------------
grey->edge detector
#include "stdafx.h"
#include <cv.h>
#include <highgui.h>
#include <cxcore.h>
#include <math.h>
using namespace cv;
int main()
{
 IplImage* img = cvLoadImage("C:\\ENEL\\OpenCV2.1\\samples\\c\\airplane.jpg");
 IplImage* edge = cvCreateImage(cvGetSize(img), IPL_DEPTH_8U, 1);
 cvCvtColor(img, edge, CV_BGR2GRAY);
 cvCanny(edge, edge, 0.3, 0.8);
 cvShowImage( "Example1", edge );
 cvWaitKey(0);
 cvReleaseImage(&img);
 cvReleaseImage(&edge);
}
----------------------------------------------------------
video writer
int main( int argc, char* argv[] ) {
    CvCapture* capture = 0;
    capture = cvCreateFileCapture( "C:\\ENEL\\OpenCV2.1\\samples\\c\\tree.avi" );
    if(!capture){
        return -1;
    }
    double fps = cvGetCaptureProperty (
        capture,
        CV_CAP_PROP_FPS
    );
 CvSize size = cvSize(
       (int)cvGetCaptureProperty( capture, CV_CAP_PROP_FRAME_WIDTH),
       (int)cvGetCaptureProperty( capture, CV_CAP_PROP_FRAME_HEIGHT)
    );
    CvVideoWriter *writer = cvCreateVideoWriter(
        "C:\\Users\\abc\\Desktop\\a.avi",
        CV_FOURCC('M','J','P','G'),
        fps,
        size
    );
    IplImage* frame = cvCreateImage(
        size,
        IPL_DEPTH_8U,
        3
    );
    while( (frame=cvQueryFrame(capture)) != NULL ) {
        cvWriteFrame( writer, frame );
    }
    cvReleaseVideoWriter( &writer );
    cvReleaseImage( &frame );
    cvReleaseCapture( &capture );
    return(0);
}
--------------------------------------------------------------
better edge detector

http://dasl.mem.drexel.edu/~noahKuntz/openCVTut5.html