77 lines
3.0 KiB
Python
Executable File
77 lines
3.0 KiB
Python
Executable File
from scipy.io import loadmat
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import torch
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from torch.utils.data import Dataset
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from torchvision.datasets.folder import default_loader
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from torchvision.datasets import ImageFolder
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from pathlib import Path
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from collections import defaultdict
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class CARS(Dataset):
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def __init__(self, root, loader=default_loader, transform=None):
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self.root = Path(root)
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self.transform = transform
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self.loader = loader
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self.annotations = loadmat(self.root / "devkit/cars_train_annos.mat")["annotations"][0]
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self.annotations = {d[-1].item(): d[-2].item() - 1 for d in self.annotations}
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self.classes_list = defaultdict(list)
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for i in range(len(self.annotations)):
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self.classes_list[self.annotations["{:05d}.jpg".format(i + 1)]].append(i)
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def __len__(self):
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return len(self.annotations)
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def __getitem__(self, item):
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file_name = "{:05d}.jpg".format(item+1)
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target = self.annotations[file_name]
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sample = self.loader(self.root / "cars_train" / file_name)
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if self.transform is not None:
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sample = self.transform(sample)
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return sample
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class ImprovedImageFolder(ImageFolder):
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def __init__(self, root, loader=default_loader, transform=None):
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super().__init__(root, transform, loader=loader)
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self.classes_list = defaultdict(list)
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for i in range(len(self)):
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self.classes_list[self.samples[i][-1]].append(i)
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def __getitem__(self, item):
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return super().__getitem__(item)[0]
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class EpisodicDataset(Dataset):
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def __init__(self, origin_dataset, num_class, num_set, num_episodes):
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self.origin = origin_dataset
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self.num_class = num_class
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assert self.num_class < len(self.origin.classes_list)
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self.num_set = num_set # K
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self.num_episodes = num_episodes
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def __len__(self):
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return self.num_episodes
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def __getitem__(self, _):
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random_classes = torch.randint(high=len(self.origin.classes_list), size=(self.num_class,)).tolist()
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support_set_list = []
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query_set_list = []
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target_list = []
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for i, c in enumerate(random_classes):
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image_list = self.origin.classes_list[c]
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if len(image_list) > self.num_set * 2:
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idx_list = torch.randperm(len(image_list))[:self.num_set*2].tolist()
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else:
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idx_list = torch.randint(high=len(image_list), size=(self.num_set*2,)).tolist()
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support_set_list.extend([self.origin[idx] for idx in idx_list[:self.num_set]])
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query_set_list.extend([self.origin[idx] for idx in idx_list[self.num_set:]])
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target_list.extend([i]*self.num_set)
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return {
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"support": torch.stack(support_set_list),
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"query": torch.stack(query_set_list),
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"target": torch.tensor(target_list)
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}
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def __repr__(self):
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return "<EpisodicDataset N={} K={} NUM={}>".format(self.num_class, self.num_set, self.num_episodes)
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