yolov3之数据集预处理

txt标签文件的说明

获取到的数据集是这样的，需要转换为VOC格式，其实就是将txt转换为xml文件：

打开txt文件可以看到以下内容：

1 0.4635416666666667 0.3016666666666667 0.39375 0.48333333333333334

id为1：目标为 mask，
该图片大小：w * h = 480 * 600

0.4635416666666667：【中心点X的比例标注】，480 * 0.4635416666666667 = 222.5 pixel

0.3016666666666667 ：【中心点Y的比例标注】 600*0.3016666666666667 = 181.0 pixel

0.39375： 【BOX宽比例标注】0.39375 * 480 = 189 pixel

0.48333333333333334： 【BOX高比例标注】0.48333333333333334 * 600 = 290 pixel

181 / 2 = 90.5
290 / 2 =145

xmin：222.5 - 90.5 = 132
xmax：222.5 + 90.5 = 313
ymin：189 - 145 = 44
ymax：189 + 145 = 334

将jpg与txt文件分开

先将txt和jpg分别分开到txt和picture文件夹下：
相关代码如下：
修改文件后缀，如果是分出txt，则将后缀改为.txt

# -*- coding:utf-8 -*-
import os
import shutil
import sys
import glob

file_type = ".jpg" #文件后缀
from_path = '.\\mask\\'  #源文件路径
to_path = '.\\picture\\'   #要复制的目标路径



from_path_list = glob.glob(from_path + '*' + file_type)
total = len(from_path_list) # 要复制的文件总数，视情况改
print('复制文件数：',total)

i = 0
interval = 5 # 打算每隔5%变化一次，视需求改
interval_num = int(total / (100 / interval)) 
# 遍历路径内的文件
for root , dirs, files in os.walk(from_path):
    for name in files:
        if name.endswith(file_type): # 只复制特定类型文件
            # print (os.path.join(root, name))
            source = os.path.join(root, name)
            target = os.path.join(to_path, name)
            try:
                shutil.copy(source, target)
            except:
                print("Copy %s failed!" % name)
            
            # 每隔5%刷新一次屏幕显示的进度百分比
            i += 1
            if (i % interval_num == 0):
                sys.stdout.write("Copy progress: %d%%   \r" % (i / interval_num * interval))
                sys.stdout.flush()

                

分开之后的效果

txt生成xml标签文件

读取txt文件，并生成xml文件，代码如下：

from xml.dom.minidom import Document
import os
import cv2
import sys


def makexml(txtPath,xmlPath,picPath): #读取txt路径，xml保存路径，数据集图片所在路径
        files_len = get_files_list_len(txtPath)

        dict = {'0': "unmask",#字典对类型进行转换，分的种类越多，这里的字典越多
                '1': "mask",
                '2': "slot_l", 
                '3': "sink_l",
                '4': "chap_l",
                '5': "block_l",
                '6': "track_l",
                '7': "plash",
                '8': "block_h"}
        files = os.listdir(txtPath)
        x = 0
        for i, name in enumerate(files):
          xmlBuilder = Document()
          annotation = xmlBuilder.createElement("annotation")  # 创建annotation标签
          xmlBuilder.appendChild(annotation)
          txtFile=open(txtPath+name)
          txtList = txtFile.readlines()
          img = cv2.imread(picPath+name[0:-4]+".jpg")
          Pheight,Pwidth,Pdepth=img.shape
          for i in txtList:
             oneline = i.strip().split(" ")

             folder = xmlBuilder.createElement("folder")#folder标签
             folderContent = xmlBuilder.createTextNode("VOC2007")
             folder.appendChild(folderContent)
             annotation.appendChild(folder)

             filename = xmlBuilder.createElement("filename")#filename标签
             filenameContent = xmlBuilder.createTextNode(name[0:-4]+".jpg")
             filename.appendChild(filenameContent)
             annotation.appendChild(filename)

             size = xmlBuilder.createElement("size")  # size标签
             width = xmlBuilder.createElement("width")  # size子标签width
             widthContent = xmlBuilder.createTextNode(str(Pwidth))
             width.appendChild(widthContent)
             size.appendChild(width)
             height = xmlBuilder.createElement("height")  # size子标签height
             heightContent = xmlBuilder.createTextNode(str(Pheight))
             height.appendChild(heightContent)
             size.appendChild(height)
             depth = xmlBuilder.createElement("depth")  # size子标签depth
             depthContent = xmlBuilder.createTextNode(str(Pdepth))
             depth.appendChild(depthContent)
             size.appendChild(depth)
             annotation.appendChild(size)

             object = xmlBuilder.createElement("object")
             picname = xmlBuilder.createElement("name")
             nameContent = xmlBuilder.createTextNode(dict[oneline[0]])
             picname.appendChild(nameContent)
             object.appendChild(picname)
             pose = xmlBuilder.createElement("pose")
             poseContent = xmlBuilder.createTextNode("Unspecified")
             pose.appendChild(poseContent)
             object.appendChild(pose)
             truncated = xmlBuilder.createElement("truncated")
             truncatedContent = xmlBuilder.createTextNode("0")
             truncated.appendChild(truncatedContent)
             object.appendChild(truncated)
             difficult = xmlBuilder.createElement("difficult")
             difficultContent = xmlBuilder.createTextNode("0")
             difficult.appendChild(difficultContent)
             object.appendChild(difficult)
             bndbox = xmlBuilder.createElement("bndbox")
             xmin = xmlBuilder.createElement("xmin")
             mathData=int(((float(oneline[1]))*Pwidth+1)-(float(oneline[3]))*0.5*Pwidth)
             xminContent = xmlBuilder.createTextNode(str(mathData))
             xmin.appendChild(xminContent)
             bndbox.appendChild(xmin)
             ymin = xmlBuilder.createElement("ymin")
             mathData = int(((float(oneline[2]))*Pheight+1)-(float(oneline[4]))*0.5*Pheight)
             yminContent = xmlBuilder.createTextNode(str(mathData))
             ymin.appendChild(yminContent)
             bndbox.appendChild(ymin)
             xmax = xmlBuilder.createElement("xmax")
             mathData = int(((float(oneline[1]))*Pwidth+1)+(float(oneline[3]))*0.5*Pwidth)
             xmaxContent = xmlBuilder.createTextNode(str(mathData))
             xmax.appendChild(xmaxContent)
             bndbox.appendChild(xmax)
             ymax = xmlBuilder.createElement("ymax")
             mathData = int(((float(oneline[2]))*Pheight+1)+(float(oneline[4]))*0.5*Pheight)
             ymaxContent = xmlBuilder.createTextNode(str(mathData))
             ymax.appendChild(ymaxContent)
             bndbox.appendChild(ymax)
             object.appendChild(bndbox)

             annotation.appendChild(object)

          f = open(xmlPath+name[0:-4]+".xml", 'w')
          xmlBuilder.writexml(f, indent='\t', newl='\n', addindent='\t', encoding='utf-8')
          f.close()
          show(files_len,x)
          x = x+1


#获取文件总数
def get_files_list_len(txtPath):
    from_path_list = os.listdir(txtPath)
    total = len(from_path_list) # 文件总数
    print('复制文件数：',total)
    return total

#转换为xml时的进度显示
def show(files_len,x):

    interval = 5 # 打算每隔5%变化一次，视需求改
    interval_num = int(files_len / (100 / interval)) 
    if (x % interval_num == 0):
        sys.stdout.write("Copy progress: %d%%   \r" % (x / interval_num * interval))
        sys.stdout.flush()


if __name__ == '__main__':
    #makexml("txt所在文件夹","xml保存地址","图片所在地址")

    makexml(".\\txt\\",".\\xml\\",".\\picture\\")

生成后的效果;

xml标签详解

获取后得到的xml标签详解：

	VOC2007          #文件夹
	test_00000002.jpg     #图片名称
	                                     #图片大小
		480
		600
		3              #图片维度
	
	

xml标签生成txt

#!/usr/bin/evn python 
#coding:utf-8 
import os

try: 
  import xml.etree.cElementTree as ET 
except ImportError: 
  import xml.etree.ElementTree as ET 
import sys 


#获取文件总数
def get_files_list_len(txtPath):
    from_path_list = os.listdir(txtPath)
    total = len(from_path_list) # 文件总数
    print('复制文件数：',total)
    return total, from_path_list

#处理进度显示
def show(files_len,x):

    interval = 5 # 打算每隔5%变化一次，视需求改
    interval_num = int(files_len / (100 / interval)) 
    if (x % interval_num == 0):
        sys.stdout.write("Copy progress: %d%%   \r" % (x / interval_num * interval))
        sys.stdout.flush()

#读取xml标签，处理为txt文件
def xml_to_txt(xml_path,txt_path):
  files_len,from_path_list = get_files_list_len(xml_path)
  for i in range(files_len):
    #file_srx = open()  #其中包含所有待计算的文件名
    #print(from_path_list[i])

    #print(line)
    #f = line[:-1]    # 除去末尾的换行符
    tree = ET.parse('.\\xml\\' + from_path_list[i])     #打开xml文档 
    root = tree.getroot()         #获得root节点  
    #print ("*"*10)
    filename = root.find('filename').text
    filename = filename[:-4]
    #print (filename) 

    file_object = open(txt_path + filename + ".txt", 'w') #写文件
    file_object_log = open(txt_path + filename + ".log", 'w') #写文件
    flag = False
    
    ########################################
    for size in root.findall('size'): #找到root节点下的size节点 
      width = size.find('width').text   #子节点下节点width的值 
      height = size.find('height').text   #子节点下节点height的值 
      #print (width, height)
    ########################################
    
    for object in root.findall('object'): #找到root节点下的所有object节点 
      name = object.find('name').text   #子节点下节点name的值 
      #print (name)
      bndbox = object.find('bndbox')      #子节点下属性bndbox的值 
      xmin = bndbox.find('xmin').text
      ymin = bndbox.find('ymin').text
      xmax = bndbox.find('xmax').text
      ymax = bndbox.find('ymax').text
      #print (xmin, ymin, xmax, ymax)

      file_object.write(name+' '+ xmin +' ' + ymin + ' ' + xmax + ' ' + ymax)

  #    if name == ("bicycle" or "motorbike"):
        #file_object.write("Cyclist" + " 0 0 0 " + xmin + ".00 " + ymin + ".00 " + xmax + ".00 " + ymax + ".00 " + "0 0 0 0 0 0 0" + "\n")
  #      file_object_log.write(str(float(int(xmax) - int(xmin)) * 1920.0 / float(width)) + " " + str(float(int(ymax) - int(ymin)) * 1080.0 / float(height)) + "\n")
  #      flag = True
  #    if name == ("car"):
        #file_object.write("Car" + " 0 0 0 " + xmin + ".00 " + ymin + ".00 " + xmax + ".00 " + ymax + ".00 " + "0 0 0 0 0 0 0" + "\n")
  #      file_object_log.write(str(float(int(xmax) - int(xmin)) * 1920.0 / float(width)) + " " + str(float(int(ymax) - int(ymin)) * 1080.0 / float(height)) + "\n")
  #      flag = True
  #    if name == ("person"):
        #file_object.write("Pedestrian" + " 0 0 0 " + xmin + ".00 " + ymin + ".00 " + xmax + ".00 " + ymax + ".00 " + "0 0 0 0 0 0 0" + "\n")
  #      file_object_log.write(str(float(int(xmax) - int(xmin)) * 1920.0 / float(width)) + " " + str(float(int(ymax) - int(ymin)) * 1080.0 / float(height)) + "\n")
  #      flag = True
    #file_object.close( )
    file_object_log.close()
    if flag == False:  #如果没有符合条件的信息，则删掉相应的txt文件以及jpg文件
      #os.remove(filename + ".txt")
      #os.remove(filename + ".jpg")
      os.remove(txt_path + filename + ".log")
    #line = file_srx.readline()
    show(files_len,i)

if __name__ == '__main__':
  
  xml_path = '.\\xml'  #读取xml路径
  txt_path = '.\\to_txt\\'   #保存txt路径
  xml_to_txt(xml_path,txt_path)

运行后效果如图

参考文献：
https://www.jianshu.com/p/c5b98b2cb7ff
https://zhuanlan.zhihu.com/p/58392978
https://blog.csdn.net/weixin_39875161/article/details/92846873
https://blog.csdn.net/xiao_lxl/article/details/85342707
https://www.cnblogs.com/rainsoul/p/6283231.html