pythonガウスノイズの追加

import cv2
import os
import glob
import skimage
import numpy as np

def add_gaussian_noise(image_in, noise_sigma):
    temp_image = np.float64(np.copy(image_in))

    h = temp_image.shape[0]
    w = temp_image.shape[1]
    noise = np.random.randn(h, w) * noise_sigma

    noisy_image = np.zeros(temp_image.shape, np.float64)
    if len(temp_image.shape) == 2:
        noisy_image = temp_image + noise
    else:
        noisy_image[:,:,0] = temp_image[:,:,0] + noise
        noisy_image[:,:,1] = temp_image[:,:,1] + noise
        noisy_image[:,:,2] = temp_image[:,:,2] + noise
    """
    print('min,max = ', np.min(noisy_image), np.max(noisy_image))
    print('type = ', type(noisy_image[0][0][0]))
    """
    return noisy_image

img_path = os.getcwd()+'/data/depart/label/1/0.png'
img = cv2.imread(img_path,0)
noise_sigma = 25
noise_img = add_gaussian_noise(img,noise_sigma=noise_sigma)
cv2.imwrite('noise_{}.png'.format(noise_sigma),noise_img)

参照先:http://www.magikcode.com/?p=240