| | """ A dataset reader that extracts images from folders |
| | |
| | Folders are scanned recursively to find image files. Labels are based |
| | on the folder hierarchy, just leaf folders by default. |
| | |
| | Hacked together by / Copyright 2020 Ross Wightman |
| | """ |
| | import os |
| | from typing import Dict, List, Optional, Set, Tuple, Union |
| |
|
| | from timm.utils.misc import natural_key |
| |
|
| | from .class_map import load_class_map |
| | from .img_extensions import get_img_extensions |
| | from .reader import Reader |
| |
|
| |
|
| | def find_images_and_targets( |
| | folder: str, |
| | types: Optional[Union[List, Tuple, Set]] = None, |
| | class_to_idx: Optional[Dict] = None, |
| | leaf_name_only: bool = True, |
| | sort: bool = True |
| | ): |
| | """ Walk folder recursively to discover images and map them to classes by folder names. |
| | |
| | Args: |
| | folder: root of folder to recursively search |
| | types: types (file extensions) to search for in path |
| | class_to_idx: specify mapping for class (folder name) to class index if set |
| | leaf_name_only: use only leaf-name of folder walk for class names |
| | sort: re-sort found images by name (for consistent ordering) |
| | |
| | Returns: |
| | A list of image and target tuples, class_to_idx mapping |
| | """ |
| | types = get_img_extensions(as_set=True) if not types else set(types) |
| | labels = [] |
| | filenames = [] |
| | for root, subdirs, files in os.walk(folder, topdown=False, followlinks=True): |
| | rel_path = os.path.relpath(root, folder) if (root != folder) else '' |
| | label = os.path.basename(rel_path) if leaf_name_only else rel_path.replace(os.path.sep, '_') |
| | for f in files: |
| | base, ext = os.path.splitext(f) |
| | if ext.lower() in types: |
| | filenames.append(os.path.join(root, f)) |
| | labels.append(label) |
| | if class_to_idx is None: |
| | |
| | unique_labels = set(labels) |
| | sorted_labels = list(sorted(unique_labels, key=natural_key)) |
| | class_to_idx = {c: idx for idx, c in enumerate(sorted_labels)} |
| | images_and_targets = [(f, class_to_idx[l]) for f, l in zip(filenames, labels) if l in class_to_idx] |
| | if sort: |
| | images_and_targets = sorted(images_and_targets, key=lambda k: natural_key(k[0])) |
| | return images_and_targets, class_to_idx |
| |
|
| |
|
| | class ReaderImageFolder(Reader): |
| |
|
| | def __init__( |
| | self, |
| | root, |
| | class_map='', |
| | input_key=None, |
| | ): |
| | super().__init__() |
| |
|
| | self.root = root |
| | class_to_idx = None |
| | if class_map: |
| | class_to_idx = load_class_map(class_map, root) |
| | find_types = None |
| | if input_key: |
| | find_types = input_key.split(';') |
| | self.samples, self.class_to_idx = find_images_and_targets( |
| | root, |
| | class_to_idx=class_to_idx, |
| | types=find_types, |
| | ) |
| | if len(self.samples) == 0: |
| | raise RuntimeError( |
| | f'Found 0 images in subfolders of {root}. ' |
| | f'Supported image extensions are {", ".join(get_img_extensions())}') |
| |
|
| | def __getitem__(self, index): |
| | path, target = self.samples[index] |
| | return open(path, 'rb'), target |
| |
|
| | def __len__(self): |
| | return len(self.samples) |
| |
|
| | def _filename(self, index, basename=False, absolute=False): |
| | filename = self.samples[index][0] |
| | if basename: |
| | filename = os.path.basename(filename) |
| | elif not absolute: |
| | filename = os.path.relpath(filename, self.root) |
| | return filename |
| |
|
