myFolderImagenet.py

import torch.utils.data as data
import numpy as np
from PIL import Image
import os
import os.path
# FROM https://discuss.pytorch.org/t/dataloader-filenames-in-each-batch/4212/2
# and https://github.com/pytorch/vision/blob/master/torchvision/datasets/folder.py#L122
IMG_EXTENSIONS = ['.jpg', '.jpeg', '.png', '.ppm', '.bmp', '.pgm']
import warnings
import pdb
def is_image_file(filename):
    """Checks if a file is an image.

    Args:
        filename (string): path to a file

    Returns:
        bool: True if the filename ends with a known image extension
    """
    filename_lower = filename.lower()
    return any(filename_lower.endswith(ext) for ext in IMG_EXTENSIONS)


def find_classes(dir):
    classes = [d for d in os.listdir(dir) if os.path.isdir(os.path.join(dir, d))]
    classes.sort()
    class_to_idx = {classes[i]: i for i in range(len(classes))}
    return classes, class_to_idx


def make_dataset(dir):
    images = []
    dir = os.path.expanduser(dir)
    for root, _, fnames in sorted(os.walk(dir)):
        for fname in sorted(fnames):
            if is_image_file(fname):
                path = os.path.join(root, fname)
                item = (path, 0)
                images.append(item)
    return images


def pil_loader(path):
    # open path as file to avoid ResourceWarning (https://github.com/python-pillow/Pillow/issues/835)
    with open(path, 'rb') as f:
        with Image.open(f) as img:
            return img.convert('RGB')


def accimage_loader(path):
    import accimage
    try:
        return accimage.Image(path)
    except IOError:
        # Potentially a decoding problem, fall back to PIL.Image
        return pil_loader(path)


def default_loader(path):
    from torchvision import get_image_backend
    if get_image_backend() == 'accimage':
        return accimage_loader(path)
    else:
        return pil_loader(path)

class MyImageFolder(data.Dataset):

    def __init__(self, root, transform=None, target_transform=None,
                 loader=default_loader):
        imgs = make_dataset(root)
        if len(imgs) == 0:
            raise(RuntimeError("Found 0 images in subfolders of: " + root + "\n"
                               "Supported image extensions are: " + ",".join(IMG_EXTENSIONS)))

        self.root = root
        self.imgs = imgs
        self.transform = transform
        self.target_transform = target_transform
        self.loader = loader
        self.n_images = len(imgs)

    def __getitem__(self, index):
        """
        Args:
            index (int): Index

        Returns:
            tuple: (image, target, path, index) where target is class_index of the target class.
        """
        path, target = self.imgs[index]

        warnings.filterwarnings('error')
        try:
            img = self.loader(path)
        except:
            return -1, -1, path, index
        if self.transform is not None:
            img = self.transform(img)
        if self.target_transform is not None:
            return "target is 0 for everybody"
        return img, target, path, index


    def __len__(self):
        return len(self.imgs)