detectron2訓練報錯

訓練時報錯報錯

-- Process 2 terminated with the following error:
Traceback (most recent call last):
  File "/home/hxw/anaconda3/envs/xinwen/lib/python3.6/site-packages/torch/multiprocessing/spawn.py", line 19, in _wrap
    fn(i, *args)
  File "/home/hxw/detectron2/detectron2/engine/launch.py", line 84, in _distributed_worker
    main_func(*args)
  File "/home/hxw/detectron2/tools/train_net.py", line 149, in main
    return trainer.train()
  File "/home/hxw/detectron2/detectron2/engine/defaults.py", line 330, in train
    super().train(self.start_iter, self.max_iter)
  File "/home/hxw/detectron2/detectron2/engine/train_loop.py", line 132, in train
    self.run_step()
  File "/home/hxw/detectron2/detectron2/engine/train_loop.py", line 206, in run_step
    data = next(self._data_loader_iter)
  File "/home/hxw/anaconda3/envs/xinwen/lib/python3.6/site-packages/torch/utils/data/dataloader.py", line 801, in __next__
    return self._process_data(data)
  File "/home/hxw/anaconda3/envs/xinwen/lib/python3.6/site-packages/torch/utils/data/dataloader.py", line 846, in _process_data
    data.reraise()
  File "/home/hxw/anaconda3/envs/xinwen/lib/python3.6/site-packages/torch/_utils.py", line 385, in reraise
    raise self.exc_type(msg)
OSError: Caught OSError in DataLoader worker process 3.
Original Traceback (most recent call last):
  File "/home/hxw/anaconda3/envs/xinwen/lib/python3.6/site-packages/torch/utils/data/_utils/worker.py", line 178, in _worker_loop
    data = fetcher.fetch(index)
  File "/home/hxw/anaconda3/envs/xinwen/lib/python3.6/site-packages/torch/utils/data/_utils/fetch.py", line 44, in fetch
    data = [self.dataset[idx] for idx in possibly_batched_index]
  File "/home/hxw/anaconda3/envs/xinwen/lib/python3.6/site-packages/torch/utils/data/_utils/fetch.py", line 44, in <listcomp>
    data = [self.dataset[idx] for idx in possibly_batched_index]
  File "/home/hxw/detectron2/detectron2/data/common.py", line 39, in __getitem__
    data = self._map_func(self._dataset[cur_idx])
  File "/home/hxw/detectron2/detectron2/data/dataset_mapper.py", line 72, in __call__
    image = utils.read_image(dataset_dict["file_name"], format=self.img_format)
  File "/home/hxw/detectron2/detectron2/data/detection_utils.py", line 53, in read_image
    image = image.convert(conversion_format)
  File "/home/hxw/anaconda3/envs/xinwen/lib/python3.6/site-packages/PIL/Image.py", line 930, in convert
    self.load()
  File "/home/hxw/anaconda3/envs/xinwen/lib/python3.6/site-packages/PIL/ImageFile.py", line 249, in load
    "(%d bytes not processed)" % len(b)
OSError: image file is truncated (7 bytes not processed)
           

單獨讀取圖檔時報錯

“premature end of JPEG file”

原因

正常JPEG檔案結束辨別EOI，檔案尾2個位元組：0xff，0xd9

異常檔案則不是這兩個辨別符，可以自行檢視。

解決辦法

代碼需要的子產品

import os
import cv2
from io import BytesIO
import skimage
import numpy as np
from PIL import Image
           

• 方式一

def is_broken_img(img_path):
    num = 0
    index = 0
    for file_ in os.listdir(img_path):
        img_ = os.path.join(img_path, file_)
        with open(img_, 'rb') as f:
            check_chars = f.read()[-2:]
        if check_chars != b'\xff\xd9':
            print("%s image is broken. "%file_)
            num += 1
        if index%2000 == 0:
            print("index of ok image: ", index)
        index += 1
    print("number of broken images: ",num)
           

應用舉例：

is_broken_img("val2017")
           

• 方式二

def is_valid_file(img_path):
    num = 0
    index = 0
    try:
        for file_ in os.listdir(img_path):
            imgfile = None
            img_ = os.path.join(img_path, file_)
            with open(img_, 'rb') as f:
                buff = BytesIO()
                buff.write(f.read())
                buff.seek(0)
                temp_img = np.array(Image.open(buff), dtype=np.uint8)
                imgfile = cv2.cvtColor(temp_img, cv2.COLOR_RGB2BGR)
                buff.close()
        
            if index%2000 == 0:
                print("index of ok image: ", index)

            index += 1
        print("success for allfiles")
    except TypeError:
        print("%s image is broken. "%file_)
           

應用舉例：

is_valid_file("train2017")
           

兩種方式自行選用，如有問題可以留言～