openCV学习笔记（七） —— 图像对比度和亮度调整、通道分离与合并

短命女 2021-09-27 04:38 366阅读 0赞

一、对比度和亮度调整

/*
    	对比度亮度调整
    */
    
    #include <opencv2/opencv.hpp>
    #include <iostream>
    
    using namespace cv;
    using namespace std;
    
    #define WIN_NAME	"输出图像"
    
    Mat src, dst;
    int contrast = 100, bright = 100;
    
    void onChange(int pos, void * data)
    {
    	for (int i = 0; i < src.rows; i++)
    	{
    		for (int j = 0; j < src.cols; j++)
    		{
    			dst.at<Vec3b>(i, j)[0] = saturate_cast<uchar>(src.at<Vec3b>(i, j)[0] * contrast*0.01 + bright);
    			dst.at<Vec3b>(i, j)[1] = saturate_cast<uchar>(src.at<Vec3b>(i, j)[1] * contrast*0.01 + bright);
    			dst.at<Vec3b>(i, j)[2] = saturate_cast<uchar>(src.at<Vec3b>(i, j)[2] * contrast*0.01 + bright);
    		}
    	}
    
    	imshow(WIN_NAME, dst);
    }
    
    int main()
    {
    	src = imread("test.jpg");
    	if (src.empty())
    	{
    		printf("can't open picture\n");
    		return -1;
    	}
    	imshow("原图", src);
    
    	dst = Mat::zeros(src.size(), src.type());
    
    	namedWindow(WIN_NAME, CV_WINDOW_AUTOSIZE);
    
    	createTrackbar("对比度", WIN_NAME, &contrast, 300, onChange, 0);
    	createTrackbar("亮 度", WIN_NAME, &bright, 200, onChange, 0);
    
    	waitKey(0);
    	destroyAllWindows();
    
    	return 0;
    }

![70][]

二、通道分离与合并

#include<opencv2/opencv.hpp>
    #include <vector>
    
    using namespace std;
    using namespace cv;
    
    int main() 
    {
    	Mat img = imread("test.jpg");
    	Mat dst;
    	vector<Mat> channels;//定义Mat类型的向量
    
    	split(img, channels);//通道分离
    	Mat blue = channels.at(0);
    	Mat green = channels.at(1);
    	Mat red = channels.at(2);
    
    	//threshold(blue, blue, 200, 255, THRESH_BINARY);//二值化：大于200的赋值255，小于200的赋值0
    	//threshold(green, green, 200, 255, THRESH_BINARY);
    	//threshold(red, red, 200, 255, THRESH_BINARY);
    
    	merge(channels, dst);//通道合并
    
    	imshow("原图", img);
    	imshow("blue", blue);
    	imshow("green", green);
    	imshow("red", red);
    	imshow("dst", dst);
    	waitKey(0);
    
    	destroyAllWindows();
    }

![70 1][]

[70]: /images/20210923/3712c04415e243b0a42284dfbb249d18.png
[70 1]: /images/20210923/0c5e30327e1c43b1a2f8bb2f9ffa34c7.png