图像预处理: 规范化

# coding=utf-8

import numpy as np
import cv2

pic_path = './Elegent_Girl.jpg'

def normalization(input):
    pic = cv2.imread(input)
    pic = pic.astype(np.float32)
    # zero-center
    pic -= [np.mean(pic[..., 0]), np.mean(pic[..., 1]), np.mean(pic[..., 2])]
    # normalize
    pic /= [np.std(pic[..., 0]), np.std(pic[..., 1]), np.std(pic[..., 2])]

    print pic[..., 0]
    pic *= (pic>0)
    pic *= 100
    pic = pic * (pic<=255) + 255 * (pic>255)
    pic = pic.astype(np.uint8)
    print pic[..., 0]
    cv2.imshow('', pic)
    cv2.waitKey(0)
    cv2.destroyAllWindows()

if __name__ == '__main__':
    # 均值0中心化(zero-center), 规范化(normalize)
    normalization(pic_path)