python

import cv2 as cv
import numpy as np
def add_salt_pepper_noise(image):
    h, w = image.shape[:2]
    nums = 10000
    row = np.random.randint(0, h, nums, dtype = np.int)
    col = np.random.randint(0, w, nums, dtype = np.int)

    for i in range(nums):
        if i % 2 == 1:
            image[row[i], col[i]] = [255, 255, 255]
        else:
            image[row[i], col[i]] = [0, 0, 0]
    return image
def add_gaussian_noise(image):
    noise = np.zeros(image.shape, image.dtype)
    m = (15, 15, 15)#mean
    n = (30, 30, 30)#stdDev
    cv.randn(noise, m, n)
    dst = cv.add(image, noise)
    cv.imshow("gaussian_noise", noise)
    return dst

img = cv.imread("../mm.jpg")
copy1 = np.copy(img)
copy2 = np.copy(img)
h, w = img.shape[:2]
result = np.zeros([h, w * 2, 3], dtype=img.dtype)
result1 = np.zeros([h, w * 2, 3], dtype=img.dtype)
dst = add_gaussian_noise(copy1)
dst1 = add_salt_pepper_noise(copy2)


result[:, : w, :] = img
result[:, w : 2 * w, :] = dst

result1[:, : w, :] = img
result1[:, w : 2 * w, :] = dst1

cv.putText(result, "origin image", (10, 30),
           cv.FONT_HERSHEY_PLAIN, 2.0, (0, 255, 255), 1)
cv.putText(result, "add_gaussian_noise", (w + 10, 30),
           cv.FONT_HERSHEY_PLAIN, 2.0, (0, 255, 255), 1)
cv.imshow("img_add_gaussian_noise", result)

cv.putText(result1, "origin image", (10, 30),
           cv.FONT_HERSHEY_PLAIN, 2.0, (0, 255, 255), 1)
cv.putText(result1, "add_salt_pepper_noise", (w + 10, 30),
           cv.FONT_HERSHEY_PLAIN, 2.0, (0, 255, 255), 1)
cv.imshow("img_add_salt_pepper_noise", result1)
cv.waitKey(0)
cv.destroyAllWindows()

python中新知识点：

• np.copy()
• cv.randn()
• cv.add()
• np.random.randint()
• cv.putText()

c++

#include "all.h"
using namespace std;
using namespace cv;
//void addGaussianNoise(Mat img);
void MyClass::day024() {
    Mat img = myRead("mm.jpg");
    Mat copy1 = img.clone();
    Mat copy2 = img.clone();
    //addGaussianNoise(copy1);
    addSaltPepperNoise(copy2);
    addGuassianNoise(copy1);
    //imshow("GaussianNoise", copy1);
    imshow("SaltPepper", copy2);
}

void MyClass::addSaltPepperNoise(Mat &img) {
    RNG rng(12345);
    int row = img.rows;
    int col = img.cols;
    int num = 10000;
    for (int i = 0; i < num; i++) {
        int x = rng.uniform(0, row);
        int y = rng.uniform(0, col);
        if (i % 2 == 1)
            img.at<Vec3b>(x, y) = Vec3b(255, 255, 255);
        else
            img.at<Vec3b>(x, y) = Vec3b(0, 0, 0);
    }
}
void MyClass::addGuassianNoise(Mat &img) {
    Mat noise = Mat::zeros(img.size(), img.type());
    randn(noise, (15, 15, 15), (30, 30, 30));
    Mat dst;
    add(img, noise, dst);
    imshow("GuassianNoise", dst);
}

c++的新知识点：

• cv::RNG:随机数产生器
• cv::randn()
• cv::add()