目标检测数据增强：同步缩放图片和xml标注

同步缩放图片（等比例缩放无失真）和xml文件标注的anchor size

import glob
import xml.dom.minidom
import cv2
from PIL import Image
import matplotlib.pyplot as plt
import os


# 定义待批量裁剪图像的路径地址
IMAGE_INPUT_PATH = r'D:\code\data\JPEGImages'
XML_INPUT_PATH = r'D:\code\data\Annotations_new'
# 定义裁剪后的图像存放地址
IMAGE_OUTPUT_PATH = r'D:\code\data\JPEGImages_out'
XML_OUTPUT_PATH = r'D:\code\data\Annotations_out'
imglist = os.listdir(IMAGE_INPUT_PATH)
xmllist = os.listdir(XML_INPUT_PATH)

for i in range(len(imglist)):
    # 每个图像全路径
    image_input_fullname = IMAGE_INPUT_PATH + '/' + imglist[i]
    xml_input_fullname = XML_INPUT_PATH + '/' + xmllist[i]
    image_output_fullname = IMAGE_OUTPUT_PATH + '/' + imglist[i]
    xml_output_fullname = XML_OUTPUT_PATH + '/' + xmllist[i]
    
    img = cv2.imread(image_input_fullname)
    height, width = img.shape[:2]
    
    # 定义缩放信息 以等比例缩放到416为例
    scale=400/height
    height=400
    width=int(width*scale)
    
    dom = xml.dom.minidom.parse(xml_input_fullname)
    root = dom.documentElement
    
    # 读取标注目标框
    objects = root.getElementsByTagName("bndbox")
    
    for object in objects:
        xmin=object.getElementsByTagName("xmin")
        xmin_data=int(float(xmin[0].firstChild.data))
        # xmin[0].firstChild.data =str(int(xmin1 * x))
        ymin =object.getElementsByTagName("ymin")
        ymin_data = int(float(ymin[0].firstChild.data))
        xmax=object.getElementsByTagName("xmax")
        xmax_data = int(float(xmax[0].firstChild.data))
        ymax=object.getElementsByTagName("ymax")
        ymax_data = int(float(ymax[0].firstChild.data))
    
        # 更新xml
        width_xml=root.getElementsByTagName("width")
        width_xml[0].firstChild.data=width
        height_xml = root.getElementsByTagName("height")
        height_xml[0].firstChild.data = height
    
        xmin[0].firstChild.data = int(xmin_data*scale)
        ymin[0].firstChild.data = int(ymin_data*scale)
        xmax[0].firstChild.data = int(xmax_data*scale)
        ymax[0].firstChild.data = int(ymax_data*scale)
    
        # 另存更新后的文件
        with open(xml_output_fullname, 'w') as f:
            dom.writexml(f, addindent='  ', encoding='utf-8')
        # 测试缩放效果
        img = cv2.resize(img, (width, height))
        '''
        # xmin, ymin, xmax, ymax分别为xml读取的坐标信息
        left_top = (int(xmin_data*scale), int(ymin_data*scale))
        right_down= (int(xmax_data*scale), int(ymax_data*scale))
        cv2.rectangle(img, left_top, right_down, (255, 0, 0), 1)
        '''
    
    cv2.imwrite(image_output_fullname,img)