YOLOv8 training custom data set

https://blog.csdn.net/weixin_42166222/article/details/129391260
https://blog.csdn.net/m0_51530640/article/details/129975257

1. Install labelme and standard data set

conda create --name=labelme python=3.6
source activate labelme
pip install pyqt5  # pyqt5 can be installed via pip on python3
pip install labelme

# 输入以下指令打开
labelme

1.1 Dataset preparation

Labelme standard json file to yolo-txt data set formatjson2txt_nomalize.py

# -*- coding: utf-8 -*-
import json
import os
import argparse
from tqdm import tqdm
 
 
def convert_label_json(json_dir, save_dir, classes):
    json_paths = os.listdir(json_dir)
    classes = classes.split(',')
 
    for json_path in tqdm(json_paths):
        # for json_path in json_paths:
        path = os.path.join(json_dir, json_path)
        with open(path, 'r') as load_f:
            json_dict = json.load(load_f)
        h, w = json_dict['imageHeight'], json_dict['imageWidth']
 
        # save txt path
        txt_path = os.path.join(save_dir, json_path.replace('json', 'txt'))
        txt_file = open(txt_path, 'w')
 
        for shape_dict in json_dict['shapes']:
            label = shape_dict['label']
            label_index = classes.index(label)
            points = shape_dict['points']
 
            points_nor_list = []
 
            for point in points:
                points_nor_list.append(point[0] / w)
                points_nor_list.append(point[1] / h)
 
            points_nor_list = list(map(lambda x: str(x), points_nor_list))
            points_nor_str = ' '.join(points_nor_list)
 
            label_str = str(label_index) + ' ' + points_nor_str + '\n'
            txt_file.writelines(label_str)
 
 
if __name__ == "__main__":
    """
    python json2txt_nomalize.py --json-dir my_datasets/color_rings/jsons --save-dir my_datasets/color_rings/txts --classes "cat,dogs"
    """
    parser = argparse.ArgumentParser(description='json convert to txt params')
    parser.add_argument('--json-dir', type=str,default='D:/ultralytics-main/data/json', help='json path dir')
    parser.add_argument('--save-dir', type=str,default='D:/ultralytics-main/data/txt' ,help='txt save dir')
    parser.add_argument('--classes', type=str, default='ccc,ccc1',help='classes')
    args = parser.parse_args()
    json_dir = args.json_dir
    save_dir = args.save_dir
    classes = args.classes
    convert_label_json(json_dir, save_dir, classes)

1.2 Divide the dataset

split_datasets.py

# 将图片和标注数据按比例切分为 训练集和测试集
import shutil
import random
import os
import argparse
 
 
# 检查文件夹是否存在
def mkdir(path):
    if not os.path.exists(path):
        os.makedirs(path)
 
def main(image_dir, txt_dir, save_dir):
    # 创建文件夹
    mkdir(save_dir)
    images_dir = os.path.join(save_dir, 'images')
    labels_dir = os.path.join(save_dir, 'labels')
 
    img_train_path = os.path.join(images_dir, 'train')
    img_test_path = os.path.join(images_dir, 'test')
    img_val_path = os.path.join(images_dir, 'val')
 
    label_train_path = os.path.join(labels_dir, 'train')
    label_test_path = os.path.join(labels_dir, 'test')
    label_val_path = os.path.join(labels_dir, 'val')
 
    mkdir(images_dir);
    mkdir(labels_dir);
    mkdir(img_train_path);
    mkdir(img_test_path);
    mkdir(img_val_path);
    mkdir(label_train_path);
    mkdir(label_test_path);
    mkdir(label_val_path);
 
    # 数据集划分比例，训练集75%，验证集15%，测试集15%，按需修改
    train_percent = 0.8
    val_percent = 0.1
    test_percent = 0.1
 
    total_txt = os.listdir(txt_dir)
    num_txt = len(total_txt)
    list_all_txt = range(num_txt)  # 范围 range(0, num)
 
    num_train = int(num_txt * train_percent)
    num_val = int(num_txt * val_percent)
    num_test = num_txt - num_train - num_val
 
    train = random.sample(list_all_txt, num_train)
    # 在全部数据集中取出train
    val_test = [i for i in list_all_txt if not i in train]
    # 再从val_test取出num_val个元素，val_test剩下的元素就是test
    val = random.sample(val_test, num_val)
 
    print("训练集数目：{}, 验证集数目：{},测试集数目：{}".format(len(train), len(val), len(val_test) - len(val)))
    for i in list_all_txt:
        name = total_txt[i][:-4]
 
        srcImage = os.path.join(image_dir, name + '.jpg')
        srcLabel = os.path.join(txt_dir, name + '.txt')
 
        if i in train:
            dst_train_Image = os.path.join(img_train_path, name + '.jpg')
            dst_train_Label = os.path.join(label_train_path, name + '.txt')
            shutil.copyfile(srcImage, dst_train_Image)
            shutil.copyfile(srcLabel, dst_train_Label)
        elif i in val:
            dst_val_Image = os.path.join(img_val_path, name + '.jpg')
            dst_val_Label = os.path.join(label_val_path, name + '.txt')
            shutil.copyfile(srcImage, dst_val_Image)
            shutil.copyfile(srcLabel, dst_val_Label)
        else:
            dst_test_Image = os.path.join(img_test_path, name + '.jpg')
            dst_test_Label = os.path.join(label_test_path, name + '.txt')
            shutil.copyfile(srcImage, dst_test_Image)
            shutil.copyfile(srcLabel, dst_test_Label)
 
 
if __name__ == '__main__':
    """
    python split_datasets.py --image-dir my_datasets/color_rings/imgs --txt-dir my_datasets/color_rings/txts --save-dir my_datasets/color_rings/train_data
    """
    parser = argparse.ArgumentParser(description='split datasets to train,val,test params')
    parser.add_argument('--image-dir', type=str,default='D:/ultralytics-main/data', help='image path dir')
    parser.add_argument('--txt-dir', type=str,default='D:/ultralytics-main/data/txt' , help='txt path dir')
    parser.add_argument('--save-dir', default='D:/ultralytics-main/data/split',type=str, help='save dir')
    args = parser.parse_args()
    image_dir = args.image_dir
    txt_dir = args.txt_dir
    save_dir = args.save_dir
 
    main(image_dir, txt_dir, save_dir)

2. Install yolo and prepare the data set

pull git clone https://github.com/ultralytics/ultralytics.git
orpip install ultralytics

Create a new weights directory to store pre-training weights.
Under the random directory, create a data directory, create a new custom.yaml,

train: /home/xxx/data/images/train
val: /home/xxx/data/images/val

# number of classes
nc: 2


# Classes
names:
  0: ccc
  1: ccc1

training and export

Method 1: The following is the official command line training/prediction/verification/export method given by yolov8:

yolo task=detect    mode=train    model=yolov8n.pt        args...
          classify       predict        yolov8n-cls.yaml  args...
          segment        val            yolov8n-seg.yaml  args...
                         export         yolov8n.pt        format=onnx  args...

# 示例
yolo task=detect   mode=train     model=weights/yolov8n.pt \
     data=data/animal.yaml        batch=16  epochs=150 imgsz=640 workers=4 device=0

Method 1: python command: New demo.py, the content is as follows:

from ultralytics import YOLO

# 加载模型
# model = YOLO("yolov8n.yaml")  # 从头开始构建新模型
model = YOLO("weights/yolov8n.pt")  # 加载预训练模型（推荐用于训练）

# Use the model
results = model.train(data="data/animal.yaml", epochs=20, batch=8)  # 训练模型