opencv学习笔记2 拖动条，亮度对比度颜色空间缩减鼠标事件

Bertha 。 2023-06-04 03:54 8阅读 0赞

1 #include <opencv2/core/core.hpp>
     2 #include<opencv2/highgui/highgui.hpp>
     3 #include"opencv2/imgproc/imgproc.hpp"
     4 #include <iostream>
     5 
     6 using namespace std;
     7 using namespace cv;
     8 
     9 static void ContrastAndBright(int, void *);
    10 
    11 int g_nContrastValue; //对比度值
    12 int g_nBrightValue;  //亮度值
    13 Mat g_srcImage, g_dstImage;
    14 
    15 int main()
    16 {
    17     //读入用户提供的图像
    18     g_srcImage = imread("E:/test.jpg");
    19 
    20     g_dstImage = Mat::zeros(g_srcImage.size(), g_srcImage.type());
    21 
    22     //设定对比度和亮度的初值
    23     g_nContrastValue = 80;
    24     g_nBrightValue = 80;
    25 
    26     //创建窗口
    27     namedWindow("【效果图窗口】", 1);
    28 
    29     //创建轨迹条
    30     createTrackbar("对比度：", "【效果图窗口】", &g_nContrastValue, 300, ContrastAndBright);
    31     createTrackbar("亮   度：", "【效果图窗口】", &g_nBrightValue, 200, ContrastAndBright);
    32 
    33     //调用回调函数
    34     ContrastAndBright(g_nContrastValue, 0);
    35     ContrastAndBright(g_nBrightValue, 0);
    36         waitKey();    
    37     return 0;
    38 }
    39 
    40 
    41 static void ContrastAndBright(int, void *)
    42 {
    43 
    44     //创建窗口
    45     namedWindow("【原始图窗口】", 1);
    46 
    47     //三个for循环，执行运算 g_dstImage(i,j) =a*g_srcImage(i,j) + b
    48     for (int y = 0; y < g_srcImage.rows; y++)
    49     {
    50         for (int x = 0; x < g_srcImage.cols; x++)
    51         {
    52             for (int c = 0; c < 3; c++)
    53             {
    54                 g_dstImage.at<Vec3b>(y, x)[c] = saturate_cast<uchar>((g_nContrastValue*0.01)*(g_srcImage.at<Vec3b>(y, x)[c]) + g_nBrightValue); //改变每个像素每个通道的值
    55             }
    56         }
    57     }
    58 
    59     //显示图像
    60     imshow("【原始图窗口】", g_srcImage);
    61     imshow("【效果图窗口】", g_dstImage);
    62 }
    
    
    颜色空间缩减

//使用动态地址遍历    
    for (int i = 0; i < src.rows; i++)
        {
            for (int j = 0; j < src.cols; j++)
            {
                for (int c = 0; c < 3; c++)
                {
                    dst.at<Vec3b>(i, j)[c] = (src.at<Vec3b>(i, j)[c] / div) *div; //每10个像素变为一个。 0-9->0 10-19->10
                }
            }
        }

//使用迭代器遍历
    dst = src.clone();
        Mat_<Vec3b>::iterator it = dst.begin<Vec3b>();
        Mat_<Vec3b>::iterator itend = dst.end<Vec3b>();
        for (; it != itend; it++)
        {
            for (int i = 0; i < 3; i++)
            {
                (*it)[i] = (*it)[i] / 10 * 10;
            }
        }

//使用鼠标画图

1 #include<opencv.hpp>
     2 #include<iostream>
     3 using namespace std;
     4 using namespace cv;
     5 #define WINDOW_NAME "程序窗口"
     6 Rect g_rectangle;
     7 bool is_Press = false;
     8 RNG g_rng(12345);
     9 
    10 
    11 void DrawRectangle(cv::Mat& img, cv::Rect box)
    12 {
    13     rectangle(img, box.tl(), box.br(), Scalar(g_rng.uniform(0, 255),
    14         g_rng.uniform(0, 255), g_rng.uniform(0, 255)));
    15 }
    16 void on_MouseHandle(int event,int x,int y,int flags,void* param)
    17 {
    18     Mat& image = *(cv::Mat*)param;
    19     switch (event)
    20     {
    21     case EVENT_MOUSEMOVE:
    22     {
    23         if (is_Press)
    24         {
    25             g_rectangle.width = x - g_rectangle.x;
    26             g_rectangle.height = y - g_rectangle.y;
    27         }
    28     }
    29     break;
    30     case EVENT_LBUTTONDOWN:
    31     {
    32         is_Press = true;
    33         g_rectangle.x = x;
    34         g_rectangle.y = y;
    35     }
    36     break;
    37     case EVENT_LBUTTONUP:
    38     {
    39         is_Press = false;
    40         if (g_rectangle.width < 0)
    41         {
    42             g_rectangle.x += g_rectangle.width;
    43             g_rectangle.width *= -1;
    44         }
    45         if (g_rectangle.height < 0)
    46         {
    47             g_rectangle.y += g_rectangle.height;
    48             g_rectangle.height *= -1;
    49         }
    50         DrawRectangle(image, g_rectangle);
    51     }
    52     break;
    53     }
    54 }
    55 
    56 int main()
    57 {
    58     g_rectangle = Rect(-1, -1, 0, 0);
    59     Mat srcImage(600, 800, CV_8UC3), tmpImage;
    60     srcImage.copyTo(tmpImage);
    61     srcImage = Scalar::all(0);
    62     
    63     namedWindow(WINDOW_NAME);
    64     setMouseCallback(WINDOW_NAME, on_MouseHandle, (void*)& srcImage);
    65     while (1)
    66     {
    67         srcImage.copyTo(tmpImage);
    68         if (is_Press)
    69             DrawRectangle(tmpImage, g_rectangle);
    70         imshow(WINDOW_NAME, tmpImage);
    71         if (waitKey(10) == 27)
    72             break;
    73     }
    74     return 0;
    75 }

转载于:https://www.cnblogs.com/sclu/p/11498900.html