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pytorch-image-models/timm/data/parsers/parser_image_folder.py

70 lines
2.4 KiB

""" A dataset parser that reads images from folders
Folders are scannerd 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 timm.utils.misc import natural_key
from .parser import Parser
from .class_map import load_class_map
from .constants import IMG_EXTENSIONS
def find_images_and_targets(folder, types=IMG_EXTENSIONS, class_to_idx=None, leaf_name_only=True, sort=True):
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:
# building class index
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 ParserImageFolder(Parser):
def __init__(
self,
root,
class_map=''):
super().__init__()
self.root = root
class_to_idx = None
if class_map:
class_to_idx = load_class_map(class_map, root)
self.samples, self.class_to_idx = find_images_and_targets(root, class_to_idx=class_to_idx)
if len(self.samples) == 0:
raise RuntimeError(
f'Found 0 images in subfolders of {root}. Supported image extensions are {", ".join(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