Opencv Canny

#include <iostream>
#include <opencv2/opencv.hpp>

using namespace std;
using namespace cv;

Mat img1, img2, img3, img_gray, kernel_x, kernel_y;

char win1[] = "window1";
char win2[] = "window2";
char win3[] = "window3";
char win4[] = "window4";

int threshold_value = 0;
int max_value = 255;
RNG rng(12345);
void Canny_C(int,void*);

//Canny
int Demo_Canny()
{
　　img1 = imread("D://images//box//0019-00.jpg");
　　if (img1.empty())
　　{
　　　　cout << "could not load image..." << endl;
　　　　return 0;
　　}
　　imshow(win1, img1);

　　createTrackbar("track", win1, &threshold_value, max_value, Canny_C);
　　Canny_C(0,0);
　　return 0;
}

void Canny_C(int, void*)
{
　　blur(img1, img2, Size(3, 3), Point(-1, -1));
　　Canny(img2, img3, threshold_value, threshold_value+3, 3, false);
　　imshow(win2, img3);
}

int main()
{
　　Demo_Canny();

　　waitKey(0);
　　return 0;
}