File size: 15,514 Bytes
f6228f9 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 |
# Ultralytics YOLO 🚀, AGPL-3.0 license
import glob
import math
import os
import random
from copy import deepcopy
from multiprocessing.pool import ThreadPool
from pathlib import Path
from typing import Optional
import cv2
import numpy as np
import psutil
from torch.utils.data import Dataset
from ultralytics.data.utils import FORMATS_HELP_MSG, HELP_URL, IMG_FORMATS
from ultralytics.utils import DEFAULT_CFG, LOCAL_RANK, LOGGER, NUM_THREADS, TQDM
class BaseDataset(Dataset):
"""
Base dataset class for loading and processing image data.
Args:
img_path (str): Path to the folder containing images.
imgsz (int, optional): Image size. Defaults to 640.
cache (bool, optional): Cache images to RAM or disk during training. Defaults to False.
augment (bool, optional): If True, data augmentation is applied. Defaults to True.
hyp (dict, optional): Hyperparameters to apply data augmentation. Defaults to None.
prefix (str, optional): Prefix to print in log messages. Defaults to ''.
rect (bool, optional): If True, rectangular training is used. Defaults to False.
batch_size (int, optional): Size of batches. Defaults to None.
stride (int, optional): Stride. Defaults to 32.
pad (float, optional): Padding. Defaults to 0.0.
single_cls (bool, optional): If True, single class training is used. Defaults to False.
classes (list): List of included classes. Default is None.
fraction (float): Fraction of dataset to utilize. Default is 1.0 (use all data).
Attributes:
im_files (list): List of image file paths.
labels (list): List of label data dictionaries.
ni (int): Number of images in the dataset.
ims (list): List of loaded images.
npy_files (list): List of numpy file paths.
transforms (callable): Image transformation function.
"""
def __init__(
self,
img_path,
imgsz=640,
cache=False,
augment=True,
hyp=DEFAULT_CFG,
prefix="",
rect=False,
batch_size=16,
stride=32,
pad=0.5,
single_cls=False,
classes=None,
fraction=1.0,
):
"""Initialize BaseDataset with given configuration and options."""
super().__init__()
self.img_path = img_path
self.imgsz = imgsz
self.augment = augment
self.single_cls = single_cls
self.prefix = prefix
self.fraction = fraction
self.im_files = self.get_img_files(self.img_path)
self.labels = self.get_labels()
self.update_labels(include_class=classes) # single_cls and include_class
self.ni = len(self.labels) # number of images
self.rect = rect
self.batch_size = batch_size
self.stride = stride
self.pad = pad
if self.rect:
assert self.batch_size is not None
self.set_rectangle()
# Buffer thread for mosaic images
self.buffer = [] # buffer size = batch size
self.max_buffer_length = min((self.ni, self.batch_size * 8, 1000)) if self.augment else 0
# Cache images (options are cache = True, False, None, "ram", "disk")
self.ims, self.im_hw0, self.im_hw = [None] * self.ni, [None] * self.ni, [None] * self.ni
self.npy_files = [Path(f).with_suffix(".npy") for f in self.im_files]
self.cache = cache.lower() if isinstance(cache, str) else "ram" if cache is True else None
if self.cache == "ram" and self.check_cache_ram():
if hyp.deterministic:
LOGGER.warning(
"WARNING ⚠️ cache='ram' may produce non-deterministic training results. "
"Consider cache='disk' as a deterministic alternative if your disk space allows."
)
self.cache_images()
elif self.cache == "disk" and self.check_cache_disk():
self.cache_images()
# Transforms
self.transforms = self.build_transforms(hyp=hyp)
def get_img_files(self, img_path):
"""Read image files."""
try:
f = [] # image files
for p in img_path if isinstance(img_path, list) else [img_path]:
p = Path(p) # os-agnostic
if p.is_dir(): # dir
f += glob.glob(str(p / "**" / "*.*"), recursive=True)
# F = list(p.rglob('*.*')) # pathlib
elif p.is_file(): # file
with open(p) as t:
t = t.read().strip().splitlines()
parent = str(p.parent) + os.sep
f += [x.replace("./", parent) if x.startswith("./") else x for x in t] # local to global path
# F += [p.parent / x.lstrip(os.sep) for x in t] # local to global path (pathlib)
else:
raise FileNotFoundError(f"{self.prefix}{p} does not exist")
im_files = sorted(x.replace("/", os.sep) for x in f if x.split(".")[-1].lower() in IMG_FORMATS)
# self.img_files = sorted([x for x in f if x.suffix[1:].lower() in IMG_FORMATS]) # pathlib
assert im_files, f"{self.prefix}No images found in {img_path}. {FORMATS_HELP_MSG}"
except Exception as e:
raise FileNotFoundError(f"{self.prefix}Error loading data from {img_path}\n{HELP_URL}") from e
if self.fraction < 1:
im_files = im_files[: round(len(im_files) * self.fraction)] # retain a fraction of the dataset
return im_files
def update_labels(self, include_class: Optional[list]):
"""Update labels to include only these classes (optional)."""
include_class_array = np.array(include_class).reshape(1, -1)
for i in range(len(self.labels)):
if include_class is not None:
cls = self.labels[i]["cls"]
bboxes = self.labels[i]["bboxes"]
segments = self.labels[i]["segments"]
keypoints = self.labels[i]["keypoints"]
j = (cls == include_class_array).any(1)
self.labels[i]["cls"] = cls[j]
self.labels[i]["bboxes"] = bboxes[j]
if segments:
self.labels[i]["segments"] = [segments[si] for si, idx in enumerate(j) if idx]
if keypoints is not None:
self.labels[i]["keypoints"] = keypoints[j]
if self.single_cls:
self.labels[i]["cls"][:, 0] = 0
def load_image(self, i, rect_mode=True):
"""Loads 1 image from dataset index 'i', returns (im, resized hw)."""
im, f, fn = self.ims[i], self.im_files[i], self.npy_files[i]
if im is None: # not cached in RAM
if fn.exists(): # load npy
try:
im = np.load(fn)
except Exception as e:
LOGGER.warning(f"{self.prefix}WARNING ⚠️ Removing corrupt *.npy image file {fn} due to: {e}")
Path(fn).unlink(missing_ok=True)
im = cv2.imread(f) # BGR
else: # read image
im = cv2.imread(f) # BGR
if im is None:
raise FileNotFoundError(f"Image Not Found {f}")
h0, w0 = im.shape[:2] # orig hw
if rect_mode: # resize long side to imgsz while maintaining aspect ratio
r = self.imgsz / max(h0, w0) # ratio
if r != 1: # if sizes are not equal
w, h = (min(math.ceil(w0 * r), self.imgsz), min(math.ceil(h0 * r), self.imgsz))
im = cv2.resize(im, (w, h), interpolation=cv2.INTER_LINEAR)
elif not (h0 == w0 == self.imgsz): # resize by stretching image to square imgsz
im = cv2.resize(im, (self.imgsz, self.imgsz), interpolation=cv2.INTER_LINEAR)
# Add to buffer if training with augmentations
if self.augment:
self.ims[i], self.im_hw0[i], self.im_hw[i] = im, (h0, w0), im.shape[:2] # im, hw_original, hw_resized
self.buffer.append(i)
if 1 < len(self.buffer) >= self.max_buffer_length: # prevent empty buffer
j = self.buffer.pop(0)
if self.cache != "ram":
self.ims[j], self.im_hw0[j], self.im_hw[j] = None, None, None
return im, (h0, w0), im.shape[:2]
return self.ims[i], self.im_hw0[i], self.im_hw[i]
def cache_images(self):
"""Cache images to memory or disk."""
b, gb = 0, 1 << 30 # bytes of cached images, bytes per gigabytes
fcn, storage = (self.cache_images_to_disk, "Disk") if self.cache == "disk" else (self.load_image, "RAM")
with ThreadPool(NUM_THREADS) as pool:
results = pool.imap(fcn, range(self.ni))
pbar = TQDM(enumerate(results), total=self.ni, disable=LOCAL_RANK > 0)
for i, x in pbar:
if self.cache == "disk":
b += self.npy_files[i].stat().st_size
else: # 'ram'
self.ims[i], self.im_hw0[i], self.im_hw[i] = x # im, hw_orig, hw_resized = load_image(self, i)
b += self.ims[i].nbytes
pbar.desc = f"{self.prefix}Caching images ({b / gb:.1f}GB {storage})"
pbar.close()
def cache_images_to_disk(self, i):
"""Saves an image as an *.npy file for faster loading."""
f = self.npy_files[i]
if not f.exists():
np.save(f.as_posix(), cv2.imread(self.im_files[i]), allow_pickle=False)
def check_cache_disk(self, safety_margin=0.5):
"""Check image caching requirements vs available disk space."""
import shutil
b, gb = 0, 1 << 30 # bytes of cached images, bytes per gigabytes
n = min(self.ni, 30) # extrapolate from 30 random images
for _ in range(n):
im_file = random.choice(self.im_files)
im = cv2.imread(im_file)
if im is None:
continue
b += im.nbytes
if not os.access(Path(im_file).parent, os.W_OK):
self.cache = None
LOGGER.info(f"{self.prefix}Skipping caching images to disk, directory not writeable ⚠️")
return False
disk_required = b * self.ni / n * (1 + safety_margin) # bytes required to cache dataset to disk
total, used, free = shutil.disk_usage(Path(self.im_files[0]).parent)
if disk_required > free:
self.cache = None
LOGGER.info(
f"{self.prefix}{disk_required / gb:.1f}GB disk space required, "
f"with {int(safety_margin * 100)}% safety margin but only "
f"{free / gb:.1f}/{total / gb:.1f}GB free, not caching images to disk ⚠️"
)
return False
return True
def check_cache_ram(self, safety_margin=0.5):
"""Check image caching requirements vs available memory."""
b, gb = 0, 1 << 30 # bytes of cached images, bytes per gigabytes
n = min(self.ni, 30) # extrapolate from 30 random images
for _ in range(n):
im = cv2.imread(random.choice(self.im_files)) # sample image
if im is None:
continue
ratio = self.imgsz / max(im.shape[0], im.shape[1]) # max(h, w) # ratio
b += im.nbytes * ratio**2
mem_required = b * self.ni / n * (1 + safety_margin) # GB required to cache dataset into RAM
mem = psutil.virtual_memory()
if mem_required > mem.available:
self.cache = None
LOGGER.info(
f"{self.prefix}{mem_required / gb:.1f}GB RAM required to cache images "
f"with {int(safety_margin * 100)}% safety margin but only "
f"{mem.available / gb:.1f}/{mem.total / gb:.1f}GB available, not caching images ⚠️"
)
return False
return True
def set_rectangle(self):
"""Sets the shape of bounding boxes for YOLO detections as rectangles."""
bi = np.floor(np.arange(self.ni) / self.batch_size).astype(int) # batch index
nb = bi[-1] + 1 # number of batches
s = np.array([x.pop("shape") for x in self.labels]) # hw
ar = s[:, 0] / s[:, 1] # aspect ratio
irect = ar.argsort()
self.im_files = [self.im_files[i] for i in irect]
self.labels = [self.labels[i] for i in irect]
ar = ar[irect]
# Set training image shapes
shapes = [[1, 1]] * nb
for i in range(nb):
ari = ar[bi == i]
mini, maxi = ari.min(), ari.max()
if maxi < 1:
shapes[i] = [maxi, 1]
elif mini > 1:
shapes[i] = [1, 1 / mini]
self.batch_shapes = np.ceil(np.array(shapes) * self.imgsz / self.stride + self.pad).astype(int) * self.stride
self.batch = bi # batch index of image
def __getitem__(self, index):
"""Returns transformed label information for given index."""
return self.transforms(self.get_image_and_label(index))
def get_image_and_label(self, index):
"""Get and return label information from the dataset."""
label = deepcopy(self.labels[index]) # requires deepcopy() https://github.com/ultralytics/ultralytics/pull/1948
label.pop("shape", None) # shape is for rect, remove it
label["img"], label["ori_shape"], label["resized_shape"] = self.load_image(index)
label["ratio_pad"] = (
label["resized_shape"][0] / label["ori_shape"][0],
label["resized_shape"][1] / label["ori_shape"][1],
) # for evaluation
if self.rect:
label["rect_shape"] = self.batch_shapes[self.batch[index]]
return self.update_labels_info(label)
def __len__(self):
"""Returns the length of the labels list for the dataset."""
return len(self.labels)
def update_labels_info(self, label):
"""Custom your label format here."""
return label
def build_transforms(self, hyp=None):
"""
Users can customize augmentations here.
Example:
```python
if self.augment:
# Training transforms
return Compose([])
else:
# Val transforms
return Compose([])
```
"""
raise NotImplementedError
def get_labels(self):
"""
Users can customize their own format here.
Note:
Ensure output is a dictionary with the following keys:
```python
dict(
im_file=im_file,
shape=shape, # format: (height, width)
cls=cls,
bboxes=bboxes, # xywh
segments=segments, # xy
keypoints=keypoints, # xy
normalized=True, # or False
bbox_format="xyxy", # or xywh, ltwh
)
```
"""
raise NotImplementedError
|