yolov6 / yolov6 /data /datasets.py
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#!/usr/bin/env python3
# -*- coding:utf-8 -*-
import glob
import os
import os.path as osp
import random
import json
import time
from multiprocessing.pool import Pool
import cv2
import numpy as np
import torch
from PIL import ExifTags, Image, ImageOps
from torch.utils.data import Dataset
from tqdm import tqdm
from pathlib import Path
from .data_augment import (
augment_hsv,
letterbox,
mixup,
random_affine,
mosaic_augmentation,
)
from yolov6.utils.events import LOGGER
# Parameters
IMG_FORMATS = ["bmp", "jpg", "jpeg", "png", "tif", "tiff", "dng", "webp", "mpo"]
# Get orientation exif tag
for k, v in ExifTags.TAGS.items():
if v == "Orientation":
ORIENTATION = k
break
class TrainValDataset(Dataset):
# YOLOv6 train_loader/val_loader, loads images and labels for training and validation
def __init__(
self,
img_dir,
img_size=640,
batch_size=16,
augment=False,
hyp=None,
rect=False,
check_images=False,
check_labels=False,
stride=32,
pad=0.0,
rank=-1,
class_names=None,
task="train",
):
assert task.lower() in ("train", "val", "speed"), f"Not supported task: {task}"
t1 = time.time()
self.__dict__.update(locals())
self.main_process = self.rank in (-1, 0)
self.task = self.task.capitalize()
self.img_paths, self.labels = self.get_imgs_labels(self.img_dir)
if self.rect:
shapes = [self.img_info[p]["shape"] for p in self.img_paths]
self.shapes = np.array(shapes, dtype=np.float64)
self.batch_indices = np.floor(
np.arange(len(shapes)) / self.batch_size
).astype(
np.int
) # batch indices of each image
self.sort_files_shapes()
t2 = time.time()
if self.main_process:
LOGGER.info(f"%.1fs for dataset initialization." % (t2 - t1))
def __len__(self):
"""Get the length of dataset"""
return len(self.img_paths)
def __getitem__(self, index):
"""Fetching a data sample for a given key.
This function applies mosaic and mixup augments during training.
During validation, letterbox augment is applied.
"""
# Mosaic Augmentation
if self.augment and random.random() < self.hyp["mosaic"]:
img, labels = self.get_mosaic(index)
shapes = None
# MixUp augmentation
if random.random() < self.hyp["mixup"]:
img_other, labels_other = self.get_mosaic(
random.randint(0, len(self.img_paths) - 1)
)
img, labels = mixup(img, labels, img_other, labels_other)
else:
# Load image
img, (h0, w0), (h, w) = self.load_image(index)
# Letterbox
shape = (
self.batch_shapes[self.batch_indices[index]]
if self.rect
else self.img_size
) # final letterboxed shape
img, ratio, pad = letterbox(img, shape, auto=False, scaleup=self.augment)
shapes = (h0, w0), ((h / h0, w / w0), pad) # for COCO mAP rescaling
labels = self.labels[index].copy()
if labels.size:
w *= ratio
h *= ratio
# new boxes
boxes = np.copy(labels[:, 1:])
boxes[:, 0] = (
w * (labels[:, 1] - labels[:, 3] / 2) + pad[0]
) # top left x
boxes[:, 1] = (
h * (labels[:, 2] - labels[:, 4] / 2) + pad[1]
) # top left y
boxes[:, 2] = (
w * (labels[:, 1] + labels[:, 3] / 2) + pad[0]
) # bottom right x
boxes[:, 3] = (
h * (labels[:, 2] + labels[:, 4] / 2) + pad[1]
) # bottom right y
labels[:, 1:] = boxes
if self.augment:
img, labels = random_affine(
img,
labels,
degrees=self.hyp["degrees"],
translate=self.hyp["translate"],
scale=self.hyp["scale"],
shear=self.hyp["shear"],
new_shape=(self.img_size, self.img_size),
)
if len(labels):
h, w = img.shape[:2]
labels[:, [1, 3]] = labels[:, [1, 3]].clip(0, w - 1e-3) # x1, x2
labels[:, [2, 4]] = labels[:, [2, 4]].clip(0, h - 1e-3) # y1, y2
boxes = np.copy(labels[:, 1:])
boxes[:, 0] = ((labels[:, 1] + labels[:, 3]) / 2) / w # x center
boxes[:, 1] = ((labels[:, 2] + labels[:, 4]) / 2) / h # y center
boxes[:, 2] = (labels[:, 3] - labels[:, 1]) / w # width
boxes[:, 3] = (labels[:, 4] - labels[:, 2]) / h # height
labels[:, 1:] = boxes
if self.augment:
img, labels = self.general_augment(img, labels)
labels_out = torch.zeros((len(labels), 6))
if len(labels):
labels_out[:, 1:] = torch.from_numpy(labels)
# Convert
img = img.transpose((2, 0, 1))[::-1] # HWC to CHW, BGR to RGB
img = np.ascontiguousarray(img)
return torch.from_numpy(img), labels_out, self.img_paths[index], shapes
def load_image(self, index):
"""Load image.
This function loads image by cv2, resize original image to target shape(img_size) with keeping ratio.
Returns:
Image, original shape of image, resized image shape
"""
path = self.img_paths[index]
im = cv2.imread(path)
assert im is not None, f"Image Not Found {path}, workdir: {os.getcwd()}"
h0, w0 = im.shape[:2] # origin shape
r = self.img_size / max(h0, w0)
if r != 1:
im = cv2.resize(
im,
(int(w0 * r), int(h0 * r)),
interpolation=cv2.INTER_AREA
if r < 1 and not self.augment
else cv2.INTER_LINEAR,
)
return im, (h0, w0), im.shape[:2]
@staticmethod
def collate_fn(batch):
"""Merges a list of samples to form a mini-batch of Tensor(s)"""
img, label, path, shapes = zip(*batch)
for i, l in enumerate(label):
l[:, 0] = i # add target image index for build_targets()
return torch.stack(img, 0), torch.cat(label, 0), path, shapes
def get_imgs_labels(self, img_dir):
assert osp.exists(img_dir), f"{img_dir} is an invalid directory path!"
valid_img_record = osp.join(
osp.dirname(img_dir), "." + osp.basename(img_dir) + ".json"
)
img_info = {}
NUM_THREADS = min(8, os.cpu_count())
# check images
if (
self.check_images or not osp.exists(valid_img_record)
) and self.main_process:
img_paths = glob.glob(osp.join(img_dir, "*"), recursive=True)
img_paths = sorted(
p for p in img_paths if p.split(".")[-1].lower() in IMG_FORMATS
)
assert img_paths, f"No images found in {img_dir}."
nc, msgs = 0, [] # number corrupt, messages
LOGGER.info(
f"{self.task}: Checking formats of images with {NUM_THREADS} process(es): "
)
with Pool(NUM_THREADS) as pool:
pbar = tqdm(
pool.imap(TrainValDataset.check_image, img_paths),
total=len(img_paths),
)
for img_path, shape_per_img, nc_per_img, msg in pbar:
if nc_per_img == 0: # not corrupted
img_info[img_path] = {"shape": shape_per_img}
nc += nc_per_img
if msg:
msgs.append(msg)
pbar.desc = f"{nc} image(s) corrupted"
pbar.close()
if msgs:
LOGGER.info("\n".join(msgs))
# save valid image paths.
with open(valid_img_record, "w") as f:
json.dump(img_info, f)
# check and load anns
label_dir = osp.join(
osp.dirname(osp.dirname(img_dir)), "labels", osp.basename(img_dir)
)
assert osp.exists(label_dir), f"{label_dir} is an invalid directory path!"
if not img_info:
with open(valid_img_record, "r") as f:
img_info = json.load(f)
assert (
img_info
), "No information in record files, please add option --check_images."
img_paths = list(img_info.keys())
label_paths = [
osp.join(label_dir, osp.basename(p).split(".")[0] + ".txt")
for p in img_paths
]
if (
self.check_labels or "labels" not in img_info[img_paths[0]]
): # key 'labels' not saved in img_info
nm, nf, ne, nc, msgs = 0, 0, 0, 0, [] # number corrupt, messages
LOGGER.info(
f"{self.task}: Checking formats of labels with {NUM_THREADS} process(es): "
)
with Pool(NUM_THREADS) as pool:
pbar = pool.imap(
TrainValDataset.check_label_files, zip(img_paths, label_paths)
)
pbar = tqdm(pbar, total=len(label_paths)) if self.main_process else pbar
for (
img_path,
labels_per_file,
nc_per_file,
nm_per_file,
nf_per_file,
ne_per_file,
msg,
) in pbar:
if img_path:
img_info[img_path]["labels"] = labels_per_file
else:
img_info.pop(img_path)
nc += nc_per_file
nm += nm_per_file
nf += nf_per_file
ne += ne_per_file
if msg:
msgs.append(msg)
if self.main_process:
pbar.desc = f"{nf} label(s) found, {nm} label(s) missing, {ne} label(s) empty, {nc} invalid label files"
if self.main_process:
pbar.close()
with open(valid_img_record, "w") as f:
json.dump(img_info, f)
if msgs:
LOGGER.info("\n".join(msgs))
if nf == 0:
LOGGER.warning(
f"WARNING: No labels found in {osp.dirname(self.img_paths[0])}. "
)
else:
with open(valid_img_record) as f:
img_info = json.load(f)
if self.task.lower() == "val":
assert (
self.class_names
), "Class names is required when converting labels to coco format for evaluating."
save_dir = osp.join(osp.dirname(osp.dirname(img_dir)), "annotations")
if not osp.exists(save_dir):
os.mkdir(save_dir)
save_path = osp.join(
save_dir, "instances_" + osp.basename(img_dir) + ".json"
)
if not osp.exists(save_path):
TrainValDataset.generate_coco_format_labels(
img_info, self.class_names, save_path
)
img_paths, labels = list(
zip(
*[
(
img_path,
np.array(info["labels"], dtype=np.float32)
if info["labels"]
else np.zeros((0, 5), dtype=np.float32),
)
for img_path, info in img_info.items()
]
)
)
self.img_info = img_info
LOGGER.info(
f"{self.task}: Final numbers of valid images: {len(img_paths)}/ labels: {len(labels)}. "
)
return img_paths, labels
def get_mosaic(self, index):
"""Gets images and labels after mosaic augments"""
indices = [index] + random.choices(
range(0, len(self.img_paths)), k=3
) # 3 additional image indices
random.shuffle(indices)
imgs, hs, ws, labels = [], [], [], []
for index in indices:
img, _, (h, w) = self.load_image(index)
labels_per_img = self.labels[index]
imgs.append(img)
hs.append(h)
ws.append(w)
labels.append(labels_per_img)
img, labels = mosaic_augmentation(self.img_size, imgs, hs, ws, labels, self.hyp)
return img, labels
def general_augment(self, img, labels):
"""Gets images and labels after general augment
This function applies hsv, random ud-flip and random lr-flips augments.
"""
nl = len(labels)
# HSV color-space
augment_hsv(
img,
hgain=self.hyp["hsv_h"],
sgain=self.hyp["hsv_s"],
vgain=self.hyp["hsv_v"],
)
# Flip up-down
if random.random() < self.hyp["flipud"]:
img = np.flipud(img)
if nl:
labels[:, 2] = 1 - labels[:, 2]
# Flip left-right
if random.random() < self.hyp["fliplr"]:
img = np.fliplr(img)
if nl:
labels[:, 1] = 1 - labels[:, 1]
return img, labels
def sort_files_shapes(self):
# Sort by aspect ratio
batch_num = self.batch_indices[-1] + 1
s = self.shapes # wh
ar = s[:, 1] / s[:, 0] # aspect ratio
irect = ar.argsort()
self.img_paths = [self.img_paths[i] for i in irect]
self.labels = [self.labels[i] for i in irect]
self.shapes = s[irect] # wh
ar = ar[irect]
# Set training image shapes
shapes = [[1, 1]] * batch_num
for i in range(batch_num):
ari = ar[self.batch_indices == 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.img_size / self.stride + self.pad).astype(
np.int
)
* self.stride
)
@staticmethod
def check_image(im_file):
# verify an image.
nc, msg = 0, ""
try:
im = Image.open(im_file)
im.verify() # PIL verify
shape = im.size # (width, height)
im_exif = im._getexif()
if im_exif and ORIENTATION in im_exif:
rotation = im_exif[ORIENTATION]
if rotation in (6, 8):
shape = (shape[1], shape[0])
assert (shape[0] > 9) & (shape[1] > 9), f"image size {shape} <10 pixels"
assert im.format.lower() in IMG_FORMATS, f"invalid image format {im.format}"
if im.format.lower() in ("jpg", "jpeg"):
with open(im_file, "rb") as f:
f.seek(-2, 2)
if f.read() != b"\xff\xd9": # corrupt JPEG
ImageOps.exif_transpose(Image.open(im_file)).save(
im_file, "JPEG", subsampling=0, quality=100
)
msg += f"WARNING: {im_file}: corrupt JPEG restored and saved"
return im_file, shape, nc, msg
except Exception as e:
nc = 1
msg = f"WARNING: {im_file}: ignoring corrupt image: {e}"
return im_file, None, nc, msg
@staticmethod
def check_label_files(args):
img_path, lb_path = args
nm, nf, ne, nc, msg = 0, 0, 0, 0, "" # number (missing, found, empty, message
try:
if osp.exists(lb_path):
nf = 1 # label found
with open(lb_path, "r") as f:
labels = [
x.split() for x in f.read().strip().splitlines() if len(x)
]
labels = np.array(labels, dtype=np.float32)
if len(labels):
assert all(
len(l) == 5 for l in labels
), f"{lb_path}: wrong label format."
assert (
labels >= 0
).all(), f"{lb_path}: Label values error: all values in label file must > 0"
assert (
labels[:, 1:] <= 1
).all(), f"{lb_path}: Label values error: all coordinates must be normalized"
_, indices = np.unique(labels, axis=0, return_index=True)
if len(indices) < len(labels): # duplicate row check
labels = labels[indices] # remove duplicates
msg += f"WARNING: {lb_path}: {len(labels) - len(indices)} duplicate labels removed"
labels = labels.tolist()
else:
ne = 1 # label empty
labels = []
else:
nm = 1 # label missing
labels = []
return img_path, labels, nc, nm, nf, ne, msg
except Exception as e:
nc = 1
msg = f"WARNING: {lb_path}: ignoring invalid labels: {e}"
return None, None, nc, nm, nf, ne, msg
@staticmethod
def generate_coco_format_labels(img_info, class_names, save_path):
# for evaluation with pycocotools
dataset = {"categories": [], "annotations": [], "images": []}
for i, class_name in enumerate(class_names):
dataset["categories"].append(
{"id": i, "name": class_name, "supercategory": ""}
)
ann_id = 0
LOGGER.info(f"Convert to COCO format")
for i, (img_path, info) in enumerate(tqdm(img_info.items())):
labels = info["labels"] if info["labels"] else []
path = Path(img_path)
img_id = int(path.stem) if path.stem.isnumeric() else path.stem
img_w, img_h = info["shape"]
dataset["images"].append(
{
"file_name": os.path.basename(img_path),
"id": img_id,
"width": img_w,
"height": img_h,
}
)
if labels:
for label in labels:
c, x, y, w, h = label[:5]
# convert x,y,w,h to x1,y1,x2,y2
x1 = (x - w / 2) * img_w
y1 = (y - h / 2) * img_h
x2 = (x + w / 2) * img_w
y2 = (y + h / 2) * img_h
# cls_id starts from 0
cls_id = int(c)
w = max(0, x2 - x1)
h = max(0, y2 - y1)
dataset["annotations"].append(
{
"area": h * w,
"bbox": [x1, y1, w, h],
"category_id": cls_id,
"id": ann_id,
"image_id": img_id,
"iscrowd": 0,
# mask
"segmentation": [],
}
)
ann_id += 1
with open(save_path, "w") as f:
json.dump(dataset, f)
LOGGER.info(
f"Convert to COCO format finished. Resutls saved in {save_path}"
)