基于python的OpenCV图像1，, 目录

基于python的OpenCV图像1，, 目录

目录

1. 读入图片并显示

import cv2img = cv2.imread("longmao.jpg")cv2.imshow("longmao", img)cv2.waitKey(0) #等待按键，0表示永久等待cv2.destroyAllWindows() #完成之后销毁窗体

2. RGB通道分离

基于numpy数组的方法

r = img[:, :, 2]g = img[:, :, 1]b = img[:, :, 0]

注意：OpenCV读取的顺序是BGR。

**基于OpenCV的RGB通道分离

b, g, r = cv2.split(img) #得到三个通道的值b = cv2.split(img)[0]

3. RGB通道分离

img2 = cv2.merge([b, g, r])

4. 单像素处理

img[9, 9, 2] #通过数组索引的方式获取某个像素值，#获取第10行，第10列（从0开始）的单独R颜色分量

5. 遍历图像

img = cv2.imread("longmao.jpg")img2 = np.zeros(img.shape)for i in range(img.shape[0]):    for j in range(img.shape[1]):        img2[i, j, 0] = img[i, j, 0] #b分量        #img2[i, j, 1] = img[i, j, 1] #g分量        #img2[i, j, 2] = img[i, j, 3] #R分量        #img2[i, j] = cv2.merge([img2[i, j, 0], img2[i, j, 1], img2[i, j, 2]])cv2.imshow("copy", img2)cv2.waitKey(0)cv2.destroyAllWindows() #完成之后销毁窗体

图片的蓝色分量显示

5. 给图片添加椒盐噪声

import numpy as npimport cv2def addPepperAndSalt(img, n):    img2 = img    for i in range(n):        x = int(np.random.random() * img.shape[0])        y = int(np.random.random() * img.shape[1])        img2[x, y, 0] = 255        img2[x, y, 1] = 255        img2[x, y, 2] = 255    return img2img = cv2.imread("longmao.jpg")img2 = addPepperAndSalt(img, 5000)cv2.imshow("salt and pepper", img2)cv2.waitKey(0)cv2.destroyAllWindows()

注：np.random.random()：返回[0.0, 1)的随机数，默认是一个，括号里面可以选返回随机数的数量

6. 添加椒盐噪声进阶版

import cv2import numpy as npdef peppersalt(img, n, m):    """    Add peppersalt to image    :param img: the image you want to add noise    :param n: the total number of noise (0 <= n <= width*height)    :param m: different mode    m=1:add only white noise in whole image    m=2:add only black noise in whole image    m=3:add black and white noise in whole image    m=4:add gray scale noise range from 0 to 255    m=5:add color noise in whole image,RGB is combined randomly with every channel ranges from 0 to 255    :return: the processed image    """    img2 = img    if m == 1:        for i in range(n):            x = int(np.random.random() * img.shape[0])            y = int(np.random.random() * img.shape[1])            img2[x, y, 0] = 255 #添加白色噪声            img2[x, y, 1] = 255            img2[x, y, 2] = 255    elif m == 2:        for i in range(n):            x = int(np.random.random() * img.shape[0])            y = int(np.random.random() * img.shape[1])            img2[x, y, 0] = 0 #黑色            img2[x, y, 1] = 0            img2[x, y, 2] = 0    elif m == 3:        for i in range(n):            x = int(np.random.random() * img.shape[0])            y = int(np.random.random() * img.shape[1])            flag = np.random.random() * 255 #随机添加白色或黑色            if flag > 128:                img2[x, y, 0] = 255                img2[x, y, 1] = 255                img2[x, y, 2] = 255            else:                img2[x, y, 0] = 0                img2[x, y, 1] = 0                img2[x, y, 2] = 0    elif m == 4:        for i in range(n):            x = int(np.random.random() * img.shape[0])            y = int(np.random.random() * img.shape[1])            flag = int(np.random.random() * 255) #随机颜色            img2[x, y, 0] = flag            img2[x, y, 1] = flag            img2[x, y, 2] = flag    elif m == 5:        for i in range(n):            x = int(np.random.random() * img.shape[0])            y = int(np.random.random() * img.shape[1])            f1 = int(np.random.random() * 255) #彩色            f2 = int(np.random.random() * 255)            f3 = int(np.random.random() * 255)            img2[x, y, 0] = f1            img2[x, y, 1] = f2            img2[x, y, 2] = f3    return img2if __name__ == "__main__":    img = cv2.imread("longmao.jpg")    img = peppersalt(img, 500, 5)    cv2.imshow("salt and pepper", img)    cv2.waitKey(0)    cv2.destroyAllWindows()

7. 实现下雪demo

def snow2pic(img, n):    """        :param img: input a rgb picture    :param n: density of the snow    :return: the pic with snow in the top    """    #length, width = img.shape    #top_length = length * 0.35    for i in range(n):        x = int(np.random.random() * img.shape[0] * 0.35)        y = int(np.random.random() * img.shape[1])        img[x, y, 0] = 255  # 添加白色噪声        img[x, y, 1] = 255        img[x, y, 2] = 255    for i in range(200):        x = int(np.random.random() * img.shape[0] * 0.8)        y = int(np.random.random() * img.shape[1])        img[x, y, 0] = 255  # 添加白色噪声        img[x, y, 1] = 255        img[x, y, 2] = 255    return img        if __name__ == "__main__":    img = cv2.imread("longmao.jpg")    img = snow2pic(img, 400)    cv2.imshow("salt and pepper", img)    cv2.waitKey(0)    cv2.destroyAllWindows()

基于python的OpenCV图像1