yolov5模型修改记录，实时更新（课题需要）

```python
 #判断标签是否检测存在
if save_txt:
    import os
    tar_dir = str(save_dir / 'labels')  # 指定目标文件夹

    #if len(os.listdir(tar_dir)) == 0:  # 目标文件夹内容为空的情况下
    #    print("不存在锚框，标签不存在")
    img22 = cv2.imread(str(save_dir / p.name))  #检测是否存在图片
    if img22 is None:
        print("未检测到")

    else:  # 目标文件夹非空的情况下进行锚框剪裁
        clip_img = cv2.imread(str(save_dir / p.name))
        for *xyxy, conf, cls in reversed(det):
            x1 = int(xyxy[0].item())
            y1 = int(xyxy[1].item())
            x2 = int(xyxy[2].item())
            y2 = int(xyxy[3].item())
            save_path = str(save_dir / 'cliped.jpg')
            cliping_img = clip_img[y1:y2, x1:x2]
            cv2.imwrite(save_path,cliping_img)
            # 剪裁后进行灰度化二值化求面积
            save_path = str(save_dir / 'cliped.jpg')
            src = cv2.imread(save_path)
            gray = cv2.cvtColor(src, cv2.COLOR_BGR2GRAY)
            retval, dst = cv2.threshold(gray, 150, 255, cv2.THRESH_BINARY)
            cv2.imshow("src2", dst)
            save_path = str(save_dir / 'dst.jpg')
            cv2.imwrite(save_path,dst)
            cv2.waitKey(0)