将目标检测的xml标签中目标绘制在图像中

用xml.etree.ElementTree库来解析xml文件

1.解析:ET.parse()

2.获取根节点：getroot()

3.找节点用find() 和findall（）

4.

   .text 是内容 #本代码用到.text

   .tag 是题目

   .attrib 是属性

5.用cv2绘图

提取出来坐标，然后rectangle（图片，左上角坐标，右下角坐标，框颜色，框线粗细）

把目标名字输出：putTEXT(图片，目标名字，起始坐标，字体，字体大小，字体颜色，粗细)

其他：两个find()定位到节点下，才能去提取xmin等四个值。还有另一个xml解析库，为xml.dom.minidom

没用过，但看起来差不多。效果都一样，熟悉一个就行。

# -*- coding: utf-8 -*-
import xml.etree.ElementTree as ET  
import os,cv2

xml_file='C:/Users/nansbas/Desktop/01_000002_01244-01086_0939-0989.xml'
tree=ET.parse(xml_file)
root=tree.getroot()
imgfile='C:/Users/nansbas/Desktop/01_000002_01244-01086_0939-0989.jpg'
im = cv2.imread(imgfile)
for object in root.findall('object'):
    object_name=object.find('name').text
    Xmin=int(object.find('bndbox').find('xmin').text)
    Ymin=int(object.find('bndbox').find('ymin').text)
    Xmax=int(object.find('bndbox').find('xmax').text)
    Ymax=int(object.find('bndbox').find('ymax').text)
    color = (4, 250, 7)
    cv2.rectangle(im,(Xmin,Ymin),(Xmax,Ymax),color,2)
    font = cv2.FONT_HERSHEY_SIMPLEX  
    cv2.putText(im, object_name, (Xmin,Ymin - 7), font, 0.5, (6, 230, 230), 2)
    cv2.imshow('01',im)
cv2.imwrite('C:/Users/nansbas/Desktop/02.jpg', im)

结果如下：

上面是按单个标签进行处理，进一步的，按xml文件夹进行处理。下面是另一个xml解析库的实现。

xml.dom.minidom 同样是树状结构解析的。

# -*- coding: utf-8 -*-
from __future__ import division 
import os
import xml.dom.minidom
import cv2
  
def read_xml(ImgPath, AnnoPath, Savepath):  
  
    imagelist = os.listdir(AnnoPath)  
    for image in imagelist:  
        image_pre, ext = os.path.splitext(image)  
        imgfile = ImgPath + '/' + image_pre + '.jpg'  
        xmlfile = AnnoPath + '/'  + image_pre + '.xml'  
        im = cv2.imread(imgfile)  
        DomTree = xml.dom.minidom.parse(xmlfile)  
        annotation = DomTree.documentElement  
        filenamelist = annotation.getElementsByTagName('filename')  
        filename = filenamelist[0].childNodes[0].data  
        objectlist = annotation.getElementsByTagName('object')  
        i = 1  
        for objects in objectlist:  
  
            namelist = objects.getElementsByTagName('name')  
            objectname = namelist[0].childNodes[0].data  
            bndbox = objects.getElementsByTagName('bndbox')  
  
            for box in bndbox:  
                try:  
                    x1_list = box.getElementsByTagName('xmin')  
                    x1 = int(x1_list[0].childNodes[0].data)  
                    y1_list = box.getElementsByTagName('ymin')  
                    y1 = int(y1_list[0].childNodes[0].data)  
                    x2_list = box.getElementsByTagName('xmax')  
                    x2 = int(x2_list[0].childNodes[0].data)  
                    y2_list = box.getElementsByTagName('ymax')  
                    y2 = int(y2_list[0].childNodes[0].data)  
  
                    minX = x1  
                    minY = y1  
                    maxX = x2  
                    maxY = y2  
  
                    if(i % 9 == 0):  
                        color = (128,0,0)  
                    elif (i % 9 == 1):  
                        color = (153, 51, 0)  
                    elif (i % 9 == 2):  
                        color = (255, 204, 0)  
                    elif (i % 9 == 3):  
                        color = (0, 51, 0)  
                    elif (i % 9 == 4):  
                        color = (51, 204, 204)  
                    elif (i % 9 == 5):  
                        color = (128, 0, 128)  
                    elif (i % 9 == 6):  
                        color = (0, 255, 255)  
                    elif (i % 9 == 7):  
                        color = (60, 179, 113)  
                    elif (i % 9 == 8):  
                        color = (255, 127, 80)  
                    elif (i % 9 == 9):  
                        color = (0, 255, 0)  
                    cv2.rectangle(im,(Xmin,Ymin),(Xmax,Ymax),color,2)  
  
#                    path = Savepath + '/' + image_pre + '_New' + '.jpg'  
                    path = Savepath + '/' + image_pre + '.jpg'  
                    font = cv2.FONT_HERSHEY_SIMPLEX  
                    cv2.putText(im, objectname, (minX,minY - 7), font, 0.5, (0, 0, 255), 1)  
                    cv2.imwrite(path, im)  
  
  
                    i += 1  
                except Exception, e:  
                    print e


read_xml('C:/Users/nansbas/Desktop/01','C:/Users/nansbas/Desktop/01','C:/Users/nansbas/Desktop/01')

结果如下