how to change colour image to grey in opencv c++
#include <opencv2/opencv.hpp>
int main() {
// Read the input color image
cv::Mat colorImage = cv::imread("input_image.jpg");
// Check if the image is successfully loaded
if (colorImage.empty()) {
std::cerr << "Error: Unable to read the input image." << std::endl;
return -1;
}
// Convert the color image to grayscale
cv::Mat grayImage;
cv::cvtColor(colorImage, grayImage, cv::COLOR_BGR2GRAY);
// Save the grayscale image
cv::imwrite("output_image_gray.jpg", grayImage);
return 0;
}