OpenCV像素操作和图形绘制

像素操作

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

using namespace std;
using namespace cv;

int main(int argc, char**argv)
{
    Mat src, src_gray;
    src= imread("b.jpg");
    if (src.empty())
    {
        cout << "could not load img.." << endl;
        return -;
    }
    namedWindow("input", CV_WINDOW_AUTOSIZE);
    imshow("input", src);
/*
    cvtColor(src, src_gray, CV_BGR2GRAY);
    namedWindow("output", CV_WINDOW_AUTOSIZE);
    imshow("output", src_gray);
    int height= src_gray.rows;
    int width = src_gray.cols;
    for (int row = 0; row < height; ++row)
    {
        for (int col = 0; col < width; ++col)
        {
            int gray = src_gray.at<uchar>(row, col);
            src_gray.at<uchar>(row, col) = 255 - gray;
        }
    }

    imshow("output", src_gray);
*/
    Mat dst;
    dst.create(src.size(), src.type());

    int height = src.rows;
    int width = src.cols;
    int chn = src.channels();

    for(int row=;row<height;++row)
        for (int col = ; col < width; ++col)
        {
            if (chn == )
            {
                int gray = src_gray.at<uchar>(row, col);
                src_gray.at<uchar>(row, col) =  - gray;
            }
            else if(chn==)
            {
                dst.at<Vec3b>(row, col)[] =  - src.at<Vec3b>(row, col)[];
                dst.at<Vec3b>(row, col)[] =  - src.at<Vec3b>(row, col)[];
                dst.at<Vec3b>(row, col)[] =  - src.at<Vec3b>(row, col)[];

            }
        }
    //bitwise_not(src, dst);
    imshow("dst", dst);
    waitKey();
    return ;
}

直线，举行，圆形，椭圆的绘制与随机直线随机颜色的绘制

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

using namespace std;
using namespace cv;

Mat src;
const char *drawdemo_win = "draw shapes and text demo";
void MyLines();
void MyRectangle();
void MyEclipse();
void MyCircle();
void MyPolygon();
void RandomLineDemo();

int main(int argc, char **argv)
{
    src = imread("b.jpg");
    if (src.empty())
    {
        cout << "Load image failed" << endl;
        return -;
    }
    imshow("input image", src);
    //MyLines();
    //MyRectangle();
    //MyEclipse();
    //MyCircle();
    //MyPolygon();
    //MyPolygon();
    //putText(src, "Hello OpenCV", Point(300, 300), CV_FONT_HERSHEY_COMPLEX, 1.0, Scalar(12, 255, 255), 3, 8);
    RandomLineDemo();
    imshow("draw", src);
    waitKey();

    return ;
}

void MyLines()
{
    Point p1 = Point(, );
    Point p2;
    p2.x = ;
    p2.y = ;
    Scalar color = Scalar(, , );
    line(src, p1, p2, color, , LINE_AA);
}

void MyRectangle()
{
    Rect rect = Rect(, , , );
    Scalar color = Scalar(, , );
    rectangle(src, rect, color, , LINE_8);
}

void MyEclipse()
{
    Scalar color = Scalar(, , );
    ellipse(src, Point(src.cols / , src.rows / ), Size(src.cols / , src.rows / ), , , , color, , LINE_8);

}

void MyCircle()
{
    Scalar color = Scalar(,, );
    Point center = Point(src.cols / , src.rows / );
    circle(src, center, ,color, , );
}

void MyPolygon()
{
    Point  pts[][];
    pts[][] = Point(, );
    pts[][] = Point(, );
    pts[][] = Point(, );
    pts[][] = Point(, );
    pts[][] = Point(, );

    const Point *ppts[] = { pts[] };
    int npt[] = {  };

    Scalar color = Scalar(, , );
    fillPoly(src, ppts, npt, , color, );
}

void RandomLineDemo()
{
    RNG rng();
    Point pt1;
    Point pt2;
    Mat bg = Mat::zeros(src.size(), src.type());
    namedWindow("Random Line Demo", CV_WINDOW_AUTOSIZE);
    for(int i=;i<;++i)
    {
        pt1.x = rng.uniform(, src.cols);
        pt2.x = rng.uniform(, src.cols);
        pt1.y = rng.uniform(, src.rows);
        pt2.y = rng.uniform(, src.rows);
        Scalar color = Scalar(rng.uniform(, ), rng.uniform(, ), rng.uniform(, ));
        if (waitKey() > )
            break;
        line(bg, pt1, pt2, color, , );
        imshow("Random Line Demo", bg);
    }
}