json转为yolo txt python代码

下面是将JSON转换为YOLO txt的Python代码：

import json
import os

# json文件路径
json_file = 'path/to/your/json/file.json'

# 类别名
classes = ["class1", "class2", "class3"]

# yolo txt文件路径
txt_file = 'path/to/your/yolo/txt/file.txt'

# 图像路径
img_dir = 'path/to/your/image/directory'

# 读取json文件
with open(json_file, 'r') as f:
    data = json.load(f)

# 解析json数据并写入yolo txt文件
with open(txt_file, 'w') as f:
    for img in data:
        img_filename = img['filename']
        img_width = img['width']
        img_height = img['height']
        for obj in img['objects']:
            class_name = obj['classTitle']
            if class_name not in classes:
                continue
            class_id = classes.index(class_name)
            x, y, w, h = obj['points']['exterior'][0] + obj['points']['exterior'][1]
            x = x / img_width
            y = y / img_height
            w = w / img_width
            h = h / img_height
            line = str(class_id) + ' ' + str(x) + ' ' + str(y) + ' ' + str(w) + ' ' + str(h) + '\n'
            f.write(os.path.join(img_dir, img_filename) + ' ' + line)

print('Convert Done!')

其中，需要将`path/to/your/json/file.json`、`path/to/your/yolo/txt/file.txt`和`path/to/your/image/directory`替换为实际的路径。在`classes`列表中，需要按照实际需要定义类别名。运行代码后，会在指定的路径下生成YOLO txt文件。