python 批量修改 labelImg 生成的xml文件的方法

Python  /  管理员 发布于 7年前   194

概述

自己在用labelImg打好标签后，想只用其中几类训练，不想训练全部类别，又不想重新打标生成.xml文件，因此想到这个办法：直接在.xml文件中删除原有的不需要的标签类及其属性。

打标时标签名出现了大小写（工程量大时可能会手滑），程序中有改写标签值为小写的过程，因为我做py-faster-rcnn 训练时，标签必须全部为小写。

以如下的.xml文件为例，我故意把标签增加了大写

<annotation verified="yes"> <filename>test.jpg</filename> <path>C:\Users\yasin\Desktop\test</path> <source> <database>Unknown</database> </source> <size> <width>400</width> <height>300</height> <depth>3</depth> </size> <segmented>0</segmented> <object> <name>People</name> <pose>Unspecified</pose> <truncated>0</truncated> <difficult>0</difficult> <bndbox>  <xmin>80</xmin>  <ymin>69</ymin>  <xmax>144</xmax>  <ymax>89</ymax> </bndbox> </object> <object> <name>CAT</name> <pose>Unspecified</pose> <truncated>0</truncated> <difficult>0</difficult> <bndbox>  <xmin>40</xmin>  <ymin>69</ymin>  <xmax>143</xmax>  <ymax>16</ymax> </bndbox> </object> <object> <name>dog</name> <pose>Unspecified</pose> <truncated>0</truncated> <difficult>0</difficult> <bndbox>  <xmin>96</xmin>  <ymin>82</ymin>  <xmax>176</xmax>  <ymax>87</ymax> </bndbox> </object> </annotation>

具体实现

假如我们只想保留图片上的people和cat类，其他都删除，代码如下：

from xml.etree.ElementTree import ElementTreefrom os import walk, pathdef read_xml(in_path):  tree = ElementTree()  tree.parse(in_path)  return treedef write_xml(tree, out_path):  tree.write(out_path, encoding="utf-8", xml_declaration=True)def find_nodes(tree, path):  return tree.findall(path)def del_node_by_target_classes(nodelist, target_classes_lower, tree_root):  for parent_node in nodelist:    children = parent_node.getchildren()    if (parent_node.tag == "object" and children[0].text.lower() not in target_classes_lower):      tree_root.remove(parent_node)    elif (parent_node.tag == "object" and children[0].text.lower() in target_classes_lower):      children[0].text = children[0].text.lower()def get_fileNames(rootdir):  data_path = []  prefixs = []  for root, dirs, files in walk(rootdir, topdown=True):    for name in files:      pre, ending = path.splitext(name)      if ending != ".xml":        continue      else:        data_path.append(path.join(root, name))        prefixs.append(pre)  return data_path, prefixsif __name__ == "__main__":  # get all the xml paths, prefixes if not used here  paths_xml, prefixs = get_fileNames("/home/yasin/old_labels/")  target_classes = ["PEOPLE", "CAT"] # target flags you want to keep  target_classes_lower = []  for i in range(len(target_classes)):    target_classes_lower.append(target_classes[i].lower()) # make sure your target is lowe-case  # print(target_classes_lower)  for i in range(len(paths_xml)):    # rename and save the corresponding xml    tree = read_xml(paths_xml[i])        # get tree node    tree_root = tree.getroot()    # get parent nodes    del_parent_nodes = find_nodes(tree, "./")        # get target classes and delete    target_del_node = del_node_by_target_classes(del_parent_nodes, target_classes_lower, tree_root)        # save output xml, 000001.xml    write_xml(tree, "/home/yasin/new_labels/{}.xml".format("%06d" % i))

按照上述代码，示例.xml变为如下.xml，可以看出我们删除了除people和cat类的类别（即dog类），并把保留类别的打标改成了小写：

<?xml version='1.0' encoding='utf-8'?><annotation verified="yes"> <filename>test.jpg</filename> <path>C:\Users\yasin\Desktop\test</path> <source> <database>Unknown</database> </source> <size> <width>400</width> <height>300</height> <depth>3</depth> </size> <segmented>0</segmented> <object> <name>people</name> <pose>Unspecified</pose> <truncated>0</truncated> <difficult>0</difficult> <bndbox>  <xmin>80</xmin>  <ymin>69</ymin>  <xmax>144</xmax>  <ymax>89</ymax> </bndbox> </object> <object> <name>cat</name> <pose>Unspecified</pose> <truncated>0</truncated> <difficult>0</difficult> <bndbox>  <xmin>40</xmin>  <ymin>69</ymin>  <xmax>143</xmax>  <ymax>16</ymax> </bndbox> </object></annotation>

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