写一手好的C++代码 ，利用Strategy模式写的

效果：把蓝天部分给提取出来

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

using namespace cv;
using namespace std;

class ColorDetector{

    private:

        int minDist;
        Vec3b target;
        Mat result;

    public:

    ColorDetector():minDist(100){
        target[0] = target[1] = target[2] = 0;
    }
    //设置色彩距离阈值
    void setColorDistanceThreshold(int distance){
        if (distance < 0)
            distance = 0;
        minDist = distance;
    }
    //get set方法设置Private里面的变量
    int getColorDistanceThreshold()const{
        return minDist;
    }
    //设置需检测的颜色
    void setTargetColor(unsigned char red, unsigned char green, unsigned char blue){
        target[2] = red;
        target[1] = green;
        target[0] = blue;
    }
    void setTargetColor(Vec3b color){
        target = color;
    }
    Vec3b getTargetColor()const{
        return target;
    }

    //计算与目标颜色的距离，采用的是街区距离
    int getDistance(const Vec3b& color) const{
        return abs(color[0] - target[0]) +
            abs(color[1] - target[1]) +
            abs(color[2] - target[2]);
    }

    Mat ColorDetector::process(const Mat &image){
        result.create(image.rows,image.cols, CV_8U);
        Mat_<Vec3b>::const_iterator it = image.begin<Vec3b>();
        Mat_<Vec3b>::const_iterator itend = image.end<Vec3b>();
        Mat_<uchar>::iterator itout = result.begin<uchar>();
        for (; it != itend; ++it, ++itout){
            if (getDistance(*it) < minDist){
                *itout = 255;
            }
            else{
                *itout = 0;
            }
        }
        return result;
    }
};

int main(){
    //创建对象
    ColorDetector cdector;
    Mat image = imread("boldt.jpg");
    if (!image.data){ return 0; }
    cdector.setTargetColor(130, 190, 230);
    namedWindow("result");
    imshow("result", cdector.process(image));
    waitKey(0);
    return 0;
}