下面是采用 CANNY 算子进行图像边缘检测的 C/C++ 源代码，在OPENCV BETA 4.0， VC6.0 环境下编译通过。关于OPENCV库的使用方法以及相关问题，请查阅下面的相关文章：
http://forum.assuredigit.com/display_topic_threads.asp?ForumID=11&TopicID=3471
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程序开始
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#ifdef _CH_
#pragma package
#endif
#ifndef _EiC
#include "cv.h"
#include "highgui.h"
#endif
char wndname[] = "Edge";
char tbarname[] = "Threshold";
int edge_thresh = 1;
IplImage *image = 0, *cedge = 0, *gray = 0, *edge = 0;
// 定义跟踪条的 callback 函数
void on_trackbar(int h)
{
cvSmooth( gray, edge, CV_BLUR, 3, 3, 0 );
cvNot( gray, edge );
// 对灰度图像进行边缘检测
cvCanny(gray, edge, (float)edge_thresh, (float)edge_thresh*3, 3);
cvZero( cedge );
// copy edge points
cvCopy( image, cedge, edge );
// 显示图像
cvShowImage(wndname, cedge);
}
int main( int argc, char** argv )
{
char* filename = argc == 2 ? argv[1] : (char*)"fruits.jpg";
if( (image = cvLoadImage( filename, 1)) == 0 )
return -1;
// Create the output image
cedge = cvCreateImage(cvSize(image->width,image->height), IPL_DEPTH_8U, 3);
// 将彩色图像转换为灰度图像
gray = cvCreateImage(cvSize(image->width,image->height), IPL_DEPTH_8U, 1);
edge = cvCreateImage(cvSize(image->width,image->height), IPL_DEPTH_8U, 1);
cvCvtColor(image, gray, CV_BGR2GRAY);
// Create a window
cvNamedWindow(wndname, 1);
// create a toolbar
cvCreateTrackbar(tbarname, wndname, &edge_thresh, 100, on_trackbar);
// Show the image
on_trackbar(0);
// Wait for a key stroke; the same function arranges events processing
cvWaitKey(0);
cvReleaseImage(&image);
cvReleaseImage(&gray);
cvReleaseImage(&edge);
cvDestroyWindow(wndname);
return 0;
}
#ifdef _EiC
main(1,"edge.c");
#endif
