Map-Detect / datasets /data_utils.py
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import random
import numpy as np
from PIL import Image
from PIL import ImageFilter
import torchvision.transforms.functional as TF
from torchvision import transforms
import torch
def to_tensor_and_norm(imgs, labels):
# to tensor
imgs = [TF.to_tensor(img) for img in imgs]
labels = [torch.from_numpy(np.array(img, np.uint8)).unsqueeze(dim=0)
for img in labels]
imgs = [TF.normalize(img, mean=[0.5, 0.5, 0.5], std=[0.5, 0.5, 0.5])
for img in imgs]
return imgs, labels
class CDDataAugmentation:
def __init__(
self,
img_size,
with_random_hflip=False,
with_random_vflip=False,
with_random_rot=False,
with_random_crop=False,
with_scale_random_crop=False,
with_random_blur=False,
):
self.img_size = img_size
if self.img_size is None:
self.img_size_dynamic = True
else:
self.img_size_dynamic = False
self.with_random_hflip = with_random_hflip
self.with_random_vflip = with_random_vflip
self.with_random_rot = with_random_rot
self.with_random_crop = with_random_crop
self.with_scale_random_crop = with_scale_random_crop
self.with_random_blur = with_random_blur
def transform(self, imgs, labels, to_tensor=True):
"""
:param imgs: [ndarray,]
:param labels: [ndarray,]
:return: [ndarray,],[ndarray,]
"""
# resize image and covert to tensor
imgs = [TF.to_pil_image(img) for img in imgs]
if self.img_size is None:
self.img_size = None
if not self.img_size_dynamic:
if imgs[0].size != (self.img_size, self.img_size):
imgs = [TF.resize(img, [self.img_size, self.img_size], interpolation=3)
for img in imgs]
else:
self.img_size = imgs[0].size[0]
labels = [TF.to_pil_image(img) for img in labels]
if len(labels) != 0:
if labels[0].size != (self.img_size, self.img_size):
labels = [TF.resize(img, [self.img_size, self.img_size], interpolation=0)
for img in labels]
random_base = 0.5
if self.with_random_hflip and random.random() > 0.5:
imgs = [TF.hflip(img) for img in imgs]
labels = [TF.hflip(img) for img in labels]
if self.with_random_vflip and random.random() > 0.5:
imgs = [TF.vflip(img) for img in imgs]
labels = [TF.vflip(img) for img in labels]
if self.with_random_rot and random.random() > random_base:
angles = [90, 180, 270]
index = random.randint(0, 2)
angle = angles[index]
imgs = [TF.rotate(img, angle) for img in imgs]
labels = [TF.rotate(img, angle) for img in labels]
if self.with_random_crop and random.random() > 0:
i, j, h, w = transforms.RandomResizedCrop(size=self.img_size). \
get_params(img=imgs[0], scale=(0.8, 1.0), ratio=(1, 1))
imgs = [TF.resized_crop(img, i, j, h, w,
size=(self.img_size, self.img_size),
interpolation=Image.CUBIC)
for img in imgs]
labels = [TF.resized_crop(img, i, j, h, w,
size=(self.img_size, self.img_size),
interpolation=Image.NEAREST)
for img in labels]
if self.with_scale_random_crop:
# rescale
scale_range = [1, 1.2]
target_scale = scale_range[0] + random.random() * (scale_range[1] - scale_range[0])
imgs = [pil_rescale(img, target_scale, order=3) for img in imgs]
labels = [pil_rescale(img, target_scale, order=0) for img in labels]
# crop
imgsize = imgs[0].size # h, w
box = get_random_crop_box(imgsize=imgsize, cropsize=self.img_size)
imgs = [pil_crop(img, box, cropsize=self.img_size, default_value=0)
for img in imgs]
labels = [pil_crop(img, box, cropsize=self.img_size, default_value=255)
for img in labels]
if self.with_random_blur and random.random() > 0:
radius = random.random()
imgs = [img.filter(ImageFilter.GaussianBlur(radius=radius))
for img in imgs]
if to_tensor:
# to tensor
imgs = [TF.to_tensor(img) for img in imgs]
labels = [torch.from_numpy(np.array(img, np.uint8)).unsqueeze(dim=0)
for img in labels]
imgs = [TF.normalize(img, mean=[0.5, 0.5, 0.5],std=[0.5, 0.5, 0.5])
for img in imgs]
return imgs, labels
def pil_crop(image, box, cropsize, default_value):
assert isinstance(image, Image.Image)
img = np.array(image)
if len(img.shape) == 3:
cont = np.ones((cropsize, cropsize, img.shape[2]), img.dtype)*default_value
else:
cont = np.ones((cropsize, cropsize), img.dtype)*default_value
cont[box[0]:box[1], box[2]:box[3]] = img[box[4]:box[5], box[6]:box[7]]
return Image.fromarray(cont)
def get_random_crop_box(imgsize, cropsize):
h, w = imgsize
ch = min(cropsize, h)
cw = min(cropsize, w)
w_space = w - cropsize
h_space = h - cropsize
if w_space > 0:
cont_left = 0
img_left = random.randrange(w_space + 1)
else:
cont_left = random.randrange(-w_space + 1)
img_left = 0
if h_space > 0:
cont_top = 0
img_top = random.randrange(h_space + 1)
else:
cont_top = random.randrange(-h_space + 1)
img_top = 0
return cont_top, cont_top+ch, cont_left, cont_left+cw, img_top, img_top+ch, img_left, img_left+cw
def pil_rescale(img, scale, order):
assert isinstance(img, Image.Image)
height, width = img.size
target_size = (int(np.round(height*scale)), int(np.round(width*scale)))
return pil_resize(img, target_size, order)
def pil_resize(img, size, order):
assert isinstance(img, Image.Image)
if size[0] == img.size[0] and size[1] == img.size[1]:
return img
if order == 3:
resample = Image.BICUBIC
elif order == 0:
resample = Image.NEAREST
return img.resize(size[::-1], resample)