C++ opencv 滑动条 Trackbary以及处理三通道和单通道图像

#include <opencv2\core.hpp>
#include <opencv2\highgui.hpp>
#include <opencv2\imgproc.hpp>

using namespace cv;

const int LowTh_Max = 20;
const int HighTh_Max = 100;
int g_HighTh, g_LowTh;
Mat srcImage;
Mat dstImage;

void on_Trackbar(int, void*);

int main(){

        g_HighTh = 80;
        g_LowTh = 0;
        srcImage = imread("F:\sfz1.jpg");
        if (!srcImage.data){ printf("fail!"); waitKey(0); return false; };
        namedWindow("1");
        imshow("1", srcImage);
        createTrackbar("LowTh:20", "1", &g_LowTh, LowTh_Max, on_Trackbar);
        createTrackbar("HighTh:100", "1", &g_HighTh, HighTh_Max, on_Trackbar);

        waitKey(0);
        return 0;
}

void on_Trackbar(int, void*){

        Canny(srcImage, dstImage, g_HighTh, g_LowTh);
        imshow("1", dstImage);

}

1. 定义全局变量及其变量的最大值（const）；

2.namedWindow和g_XXX的初始值，createTrackbar，waitKey(0);

3.写on_Trackbar(int, void*), imshow;

处理三通道图像：

void procc(Mat &src, Mat &dst){
        for (int Ch = 0; Ch < 3; Ch++){
                for (int r = 0; r < src.rows; r++){
                        for (int c = 0; c < src.cols; c++){
                                //printf("%d %d %d\n", Ch, r, c);
                                src.at<Vec3b>(r, c)[Ch] = g_sigma;
                        }
                }
        }
        src.copyTo(dst);
}

处理单通道图像：

srcImage.ptr<int>[row](col)