使用python计算自己数据集的mean和std

本文主要是介绍使用python计算自己数据集的mean和std，对大家解决编程问题具有一定的参考价值，需要的程序猿们随着小编来一起学习吧！

首先先把数据集的图片路径保存在一个txt文件夹里面

   
     
      
     
     
      
       import os
      
     
     
      
     
     
       
      
     
     
      
     
     
       
      
     
     
      
     
     
      
       def generate(dir, label):
      
     
     
      
     
     
      
           listText = open(
       'list.txt', 
       'a')
      
     
     
      
     
     
          
       for file 
       in dir:
      
     
     
      
     
     
      
               fileType = os.path.split(file)
      
     
     
      
     
     
              
       if fileType[
       1] == 
       '.txt':
      
     
     
      
     
     
                  
       continue
      
     
     
      
     
     
      
               name = file + 
       ' ' + str(int(label)) + 
       '\n'
      
     
     
      
     
     
      
               listText.write(name)
      
     
     
      
     
     
      
           listText.close()
      
     
     
      
     
     
       
      
     
     
      
     
     
      
       outer_path = 
       'E:/lly/data/'  
       # 这里是你的图片的目录
      
     
     
      
     
     
       
      
     
     
      
     
     
      
       if __name__ == 
       '__main__':
      
     
     
      
     
     
      
           i = 
       1
      
     
     
      
     
     
      
           num = 
       0
      
     
     
      
     
     
      
           personlist = os.listdir(outer_path)  
       # 列举文件夹
      
     
     
      
     
     
      
           personlist.sort()
      
     
     
      
     
     
          
       for person 
       in personlist:
      
     
     
      
     
     
      
               personPath = outer_path+person + 
       "/"
      
     
     
      
     
     
       
      
     
     
      
     
     
      
               fingerlist = os.listdir(personPath)
      
     
     
      
     
     
      
               fingerlist.sort()
      
     
     
      
     
     
       
      
     
     
      
     
     
              
       for finger 
       in fingerlist:
      
     
     
      
     
     
       
      
     
     
      
     
     
      
                   finallPATH=os.path.join(outer_path, person,finger)
      
     
     
      
     
     
      
                   finallPATH=finallPATH.replace(
       '\\', 
       '/')
      
     
     
      
     
     
       
      
     
     
      
     
     
      
                   listText = open(
       'image_list.txt', 
       'a')
      
     
     
      
     
     
      
                   fileType = os.path.split(finallPATH)
      
     
     
      
     
     
       
      
     
     
      
     
     
      
                   name = finallPATH+ 
       '\n'
      
     
     
      
     
     
       
      
     
     
      
     
     
      
                   listText.write(name)
      
     
     
      
     
     
       
      
     
     
      
     
     
      
               listText.close()
      
     
     
      
     
     
      
               i += 
       1
      
     
   

计算自己数据集的均值和方差：

   
     
      
     
     
      
       # -*- coding: utf-8 -*-**
      
     
     
      
     
     
      
       import numpy 
       as np
      
     
     
      
     
     
      
       import cv2
      
     
     
      
     
     
      
       import random
      
     
     
      
     
     
      
       import os
      
     
     
      
     
     
       
      
     
     
      
     
     
      
       # calculate means and std  注意换行\n符号**
      
     
     
      
     
     
      
       # train.txt中每一行是图像的位置信息**
      
     
     
      
     
     
      
       path = 
       'C:/Users/lenovo/PycharmProjects/my/image_list.txt'
      
     
     
      
     
     
      
       means = [
       0, 
       0, 
       0]
      
     
     
      
     
     
      
       stdevs = [
       0, 
       0, 
       0]
      
     
     
      
     
     
       
      
     
     
      
     
     
      
       index = 
       1
      
     
     
      
     
     
      
       num_imgs = 
       0
      
     
     
      
     
     
      
       with open(path, 
       'r') 
       as f:
      
     
     
      
     
     
      
           lines = f.readlines()
      
     
     
      
     
     
          
       # random.shuffle(lines)
      
     
     
      
     
     
       
      
     
     
      
     
     
          
       for line 
       in lines:
      
     
     
      
     
     
      
               print(line)
      
     
     
      
     
     
      
               print(
       '{}/{}'.format(index, len(lines)))
      
     
     
      
     
     
      
               index += 
       1
      
     
     
      
     
     
      
               a = os.path.join(line)
      
     
     
      
     
     
       
      
     
     
      
     
     
             
       # print(a[:-1])
      
     
     
      
     
     
      
               num_imgs += 
       1
      
     
     
      
     
     
      
               img = cv2.imread(a[:
       -1])
      
     
     
      
     
     
      
               print(img, 
       22)
      
     
     
      
     
     
      
               img = np.asarray(img)
      
     
     
      
     
     
       
      
     
     
      
     
     
      
               img = img.astype(np.float32) / 
       255.
      
     
     
      
     
     
              
       for i 
       in range(
       3):
      
     
     
      
     
     
      
                   means[i] += img[:, :, i].mean()
      
     
     
      
     
     
      
                   stdevs[i] += img[:, :, i].std()
      
     
     
      
     
     
      
       print(num_imgs)
      
     
     
      
     
     
      
       means.reverse()
      
     
     
      
     
     
      
       stdevs.reverse()
      
     
     
      
     
     
       
      
     
     
      
     
     
      
       means = np.asarray(means) / num_imgs
      
     
     
      
     
     
      
       stdevs = np.asarray(stdevs) / num_imgs
      
     
     
      
     
     
       
      
     
     
      
     
     
      
       print(
       "normMean = {}".format(means))
      
     
     
      
     
     
      
       print(
       "normStd = {}".format(stdevs))
      
     
     
      
     
     
      
       print(
       'transforms.Normalize(normMean = {}, normStd = {})'.format(means, stdevs))
      
     
     
      
     
     
       
      
     
   

参考：https://blog.csdn.net/weixin_38533896/article/details/85951903

这篇关于使用python计算自己数据集的mean和std的文章就介绍到这儿，希望我们推荐的文章对大家有所帮助，也希望大家多多支持为之网！