# Adding Gaussian Noise in OpenCV Mat Image

Hi Everyone! I have been trying to add Additive White Gaussian Noise in my Mat image(Using Qt 5.2.0) using the following piece of code, but i am getting the original image only. No noise is being added! Please can anyone help me by telling where I am going wrong!

    cv::Mat gaussianD;
cv::Mat gaussian = grImage.clone();
gaussian.convertTo(gaussianD, CV_32F);
cv::Mat mult = cv::Mat::zeros(grImage.rows, grImage.cols, CV_32F);
cv::randn(mult, 0, ui->doubleSpinBox_sDev->value());
gaussianD = gaussianD + sqrt(ui->doubleSpinBox_sDev->value())*mult;
gaussianD.convertTo(gaussianD, CV_8U);
cv::namedWindow("Gaussian Noise");
cv::imshow("Gaussian Noise", gaussianD);
cv::imwrite("gaussian.jpg", gaussianD);