Faster R-CNN 自定义Dataset
bilibili
spilt_data.py
files_path = "./VOCdevkit/VOC2012/Annotations"
if not os.path.exists(files_path):
print("文件夹不存在")
exit(1)
val_rate = 0.5
files_name = sorted([file.split(".")[0] for file in os.listdir(files_path)])
files_num = len(files_name)
val_index = random.sample(range(0, files_num), k=int(files_num*val_rate))
train_files = []
val_files = []
for index, file_name in enumerate(files_name):
if index in val_index:
val_files.append(file_name)
else:
train_files.append(file_name)
try:
train_f = open("train.txt", "x")
eval_f = open("val.txt", "x")
train_f.write("\n".join(train_files))
eval_f.write("\n".join(val_files))
except FileExistsError as e:
print(e)
exit(1)
my_dataset.py
from torch.utils.data import Dataset
import os
import torch
import json
from PIL import Image
from lxml import etree
class VOC2012DataSet(Dataset):
"""读取解析PASCAL VOC2012数据集"""
def __init__(self, voc_root, transforms, txt_name: str = "train.txt"):
self.root = os.path.join(voc_root, "VOCdevkit", "VOC2012")
self.img_root = os.path.join(self.root, "JPEGImages")
self.annotations_root = os.path.join(self.root, "Annotations")
# read train.txt or val.txt file
txt_path = os.path.join(self.root, "ImageSets", "Main", txt_name)
assert os.path.exists(txt_path), "not found {} file.".format(txt_name)
with open(txt_path) as read:
self.xml_list = [os.path.join(self.annotations_root, line.strip() + ".xml")
for line in read.readlines()]
# read class_indict
try:
json_file = open('./pascal_voc_classes.json', 'r')
self.class_dict = json.load(json_file)
except Exception as e:
print(e)
exit(-1)
self.transforms = transforms
def __len__(self):
return len(self.xml_list)
def __getitem__(self, idx):
# read xml
xml_path = self.xml_list[idx]
with open(xml_path) as fid:
xml_str = fid.read()
xml = etree.fromstring(xml_str)
data = self.parse_xml_to_dict(xml)["annotation"]
img_path = os.path.join(self.img_root, data["filename"])
image = Image.open(img_path)
if image.format != "JPEG":
raise ValueError("Image format not JPEG")
boxes = []
labels = []
iscrowd = []
for obj in data["object"]:
xmin = float(obj["bndbox"]["xmin"])
xmax = float(obj["bndbox"]["xmax"])
ymin = float(obj["bndbox"]["ymin"])
ymax = float(obj["bndbox"]["ymax"])
boxes.append([xmin, ymin, xmax, ymax])
labels.append(self.class_dict[obj["name"]])
iscrowd.append(int(obj["difficult"]))
# convert everything into a torch.Tensor
boxes = torch.as_tensor(boxes, dtype=torch.float32)
labels = torch.as_tensor(labels, dtype=torch.int64)
iscrowd = torch.as_tensor(iscrowd, dtype=torch.int64)
image_id = torch.tensor([idx])
area = (boxes[:, 3] - boxes[:, 1]) * (boxes[:, 2] - boxes[:, 0])
target = {
}
target["boxes"] = boxes
target["labels"] = labels
target["image_id"] = image_id
target["area"] = area
target["iscrowd"] = iscrowd
if self.transforms is not None:
image, target = self.transforms(image, target)
return image, target
def get_height_and_width(self, idx):
# read xml
xml_path = self.xml_list[idx]
with open(xml_path) as fid:
xml_str = fid.read()
xml = etree.fromstring(xml_str)
data = self.parse_xml_to_dict(xml)["annotation"]
data_height = int(data["size"]["height"])
data_width = int(data["size"]["width"])
return data_height, data_width
def parse_xml_to_dict(self, xml):
"""
将xml文件解析成字典形式，参考tensorflow的recursive_parse_xml_to_dict
Args:
xml: xml tree obtained by parsing XML file contents using lxml.etree
Returns:
Python dictionary holding XML contents.
"""
if len(xml) == 0: # 遍历到底层，直接返回tag对应的信息
return {
xml.tag: xml.text}
result = {
}
for child in xml:
child_result = self.parse_xml_to_dict(child) # 递归遍历标签信息
if child.tag != 'object':
result[child.tag] = child_result[child.tag]
else:
if child.tag not in result: # 因为object可能有多个，所以需要放入列表里
result[child.tag] = []
result[child.tag].append(child_result[child.tag])
return {
xml.tag: result}
def coco_index(self, idx):
"""
该方法是专门为pycocotools统计标签信息准备，不对图像和标签作任何处理
由于不用去读取图片，可大幅缩减统计时间
Args:
idx: 输入需要获取图像的索引
"""
# read xml
xml_path = self.xml_list[idx]
with open(xml_path) as fid:
xml_str = fid.read()
xml = etree.fromstring(xml_str)
data = self.parse_xml_to_dict(xml)["annotation"]
data_height = int(data["size"]["height"])
data_width = int(data["size"]["width"])
# img_path = os.path.join(self.img_root, data["filename"])
# image = Image.open(img_path)
# if image.format != "JPEG":
# raise ValueError("Image format not JPEG")
boxes = []
labels = []
iscrowd = []
for obj in data["object"]:
xmin = float(obj["bndbox"]["xmin"])
xmax = float(obj["bndbox"]["xmax"])
ymin = float(obj["bndbox"]["ymin"])
ymax = float(obj["bndbox"]["ymax"])
boxes.append([xmin, ymin, xmax, ymax])
labels.append(self.class_dict[obj["name"]])
iscrowd.append(int(obj["difficult"]))
# convert everything into a torch.Tensor
boxes = torch.as_tensor(boxes, dtype=torch.float32)
labels = torch.as_tensor(labels, dtype=torch.int64)
iscrowd = torch.as_tensor(iscrowd, dtype=torch.int64)
image_id = torch.tensor([idx])
area = (boxes[:, 3] - boxes[:, 1]) * (boxes[:, 2] - boxes[:, 0])
target = {
}
target["boxes"] = boxes
target["labels"] = labels
target["image_id"] = image_id
target["area"] = area
target["iscrowd"] = iscrowd
return (data_height, data_width), target
@staticmethod
def collate_fn(batch):
return tuple(zip(*batch))
# import transforms
# from draw_box_utils import draw_box
# from PIL import Image
# import json
# import matplotlib.pyplot as plt
# import torchvision.transforms as ts
# import random
#
# # read class_indict
# category_index = {}
# try:
# json_file = open('./pascal_voc_classes.json', 'r')
# class_dict = json.load(json_file)
# category_index = {v: k for k, v in class_dict.items()}
# except Exception as e:
# print(e)
# exit(-1)
#
# data_transform = {
# "train": transforms.Compose([transforms.ToTensor(),
# transforms.RandomHorizontalFlip(0.5)]),
# "val": transforms.Compose([transforms.ToTensor()])
# }
#
# # load train data set
# train_data_set = VOC2012DataSet(os.getcwd(), data_transform["train"], True)
# print(len(train_data_set))
# for index in random.sample(range(0, len(train_data_set)), k=5):
# img, target = train_data_set[index]
# img = ts.ToPILImage()(img)
# draw_box(img,
# target["boxes"].numpy(),
# target["labels"].numpy(),
# [1 for i in range(len(target["labels"].numpy()))],
# category_index,
# thresh=0.5,
# line_thickness=5)
# plt.imshow(img)
# plt.show()
transforms.py
class Compose(object):
"""组合多个transform函数"""
def __init__(self, transforms):
self.transforms = transforms
def __call__(self, image, target):
for t in self.transforms:
image, target = t(image, target)
return image, target
class ToTensor(object):
"""将PIL图像转为Tensor"""
def __call__(self, image, target):
image = F.to_tensor(image)
return image, target
class RandomHorizontalFlip(object):
"""随机水平翻转图像以及bboxes"""
def __init__(self, prob=0.5):
self.prob = prob
def __call__(self, image, target):
if random.random() < self.prob:
height, width = image.shape[-2:]
image = image.flip(-1) # 水平翻转图片
bbox = target["boxes"]
# bbox: xmin, ymin, xmax, ymax
bbox[:, [0, 2]] = width - bbox[:, [2, 0]] # 翻转对应bbox坐标信息
target["boxes"] = bbox
return image, target