bdd100k数据集中目标检测标签格式转换（json转txt）用于yolov5和yolov8

bdd100k数据集中目标检测标签格式转换（json转txt）用于yolov5和yolov8

最近在用bdd100k的目标检测数据集测试自己训练的模型，但是bdd100k中有些类别与我的不一样，我有的他没有，他有的我不需要，为了统一标签序号，仅 保留bdd100k中我需要的类别，将 json转成txt格式，设置了如下代码，需要的朋友看懂代码后自行修改使用。
代码没啥技巧，如果有更简单的写法，欢迎在评论区留言，我也想学习学习。

import json
import os

def bdd100k_json_txt(categorys,jsonFile,writepath):
    f = open(jsonFile)
    info = json.load(f)
    #print(len(info))
    #print(info["name"])

    for obj in info["frames"]:
        #print(obj["objects"])
        strs = ""
        for objects in obj["objects"]:
            #print(objects)
            if objects["category"] in categorys:
                dw = 1.0 / 1280
                dh = 1.0 / 720
                strs += str(categorys.index(objects["category"]))
                strs += " "
                strs += str(((objects["box2d"]["x1"] + objects["box2d"]["x2"]) / 2.0) * dw)[0:8]
                strs += " "
                strs += str(((objects["box2d"]["y1"] + objects["box2d"]["y2"]) / 2.0) * dh)[0:8]
                strs += " "
                strs += str(((objects["box2d"]["x2"] - objects["box2d"]["x1"])) * dw)[0:8]
                strs += " "
                strs += str(((objects["box2d"]["y2"] - objects["box2d"]["y1"])) * dh)[0:8]
                strs += "\n"
        if strs!="":
            write = open(writepath + "%s.txt" % info["name"], 'w')
            write.writelines(strs)
            write.close()
            # print("%s has been dealt!" % info["name"])
        else:
            print("%s has been dealt!" % info["name"])


if __name__ == "__main__":
    ####################args#####################
    categorys = ['traffic light', 'traffic sign', 'car', 'person', 'bus', 'truck', 'riderss',
                 'bike', 'motor', 'cone', 'barrier', 'opendoor', 'wheel', 'tail']    # 自己需要从BDD数据集里提取的目标类别
    readpath = r"D:\yolo\yolov8\data\bdd100k\det_annotations\train/"   # BDD数据集标签读取路径，这里需要分两次手动去修改train、val的地址
    writepath = r"D:\yolo\yolov8\data\bdd100k\labels\train/"	# BDD数据集转换后的标签保存路径

    fileList = os.listdir(readpath)
    #print(fileList)
    for file in fileList:
        # print(file)
        filepath = readpath + file
        bdd100k_json_txt(categorys, filepath, writepath)