#include "cv.h"#include "highgui.h"char wndname[] = "Edge";char tbarname[] = "Threshold";int edge_thresh = 1;IplImage *image = 0, *cedge = 0, *gray = 0, *edge = 0;// 定義跟蹤條的 callback 函數void on_trackbar(int h){    cvSmooth( gray, edge, CV_BLUR, 3, 3, 0 );    cvNot( gray, edge );    // 對灰度圖像進行邊緣檢測    cvCanny(gray, edge, (float)edge_thresh, (float)edge_thresh*3, 3);    cvZero( cedge );    // copy edge points    cvCopy( image, cedge, edge );    // 顯示圖像    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);    // 將彩色圖像轉換為灰度圖像    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;}