Use la biblioteca opencv para ver el valor de color RGB de una imagen

#include<opencv2/opencv.hpp>
#include<stdio.h>
using namespace std;
using namespace cv;

int main(int argc, char* argv[])
{
	Mat img = imread("C:/Users/鑫鑫/Desktop/6.jpg",-1);//正确读取照片
	FILE*f1;
	f1 = fopen("C:/Users/鑫鑫/Desktop/原图RGB.txt", "a");
	int pixelR, pixelG, pixelB;//定义三个接收RGB的变量
	
	for (int r = 0; r < img.rows; r++)
	{
		for (int c = 0; c < img.cols; c++)
		{
			pixelB = img.at<Vec3b>(r, c)[0];//注意opencvz中Scalar(B,G,R)不是R，G，B这个顺序
			pixelG = img.at<Vec3b>(r, c)[1];
			pixelR = img.at<Vec3b>(r, c)[2];
			fprintf(f1, "(%d,%d,%d)\n", pixelR, pixelG, pixelB);//输出定向到文件保存
		}
	}
	return 0;
}