loader.py

from torch.utils.data import Dataset, DataLoader
import torch
import numpy as np
import random
import os
from PIL import Image
from einops.layers.torch import Rearrange
from scipy.ndimage.morphology import binary_dilation
from torch.utils.data import Dataset
from torchvision import transforms
from scipy import ndimage
from utils import *


# ===== normalize over the dataset 
def dataset_normalized(imgs):
    imgs_normalized = np.empty(imgs.shape)
    imgs_std = np.std(imgs)
    imgs_mean = np.mean(imgs)
    imgs_normalized = (imgs-imgs_mean)/imgs_std
    for i in range(imgs.shape[0]):
        imgs_normalized[i] = ((imgs_normalized[i] - np.min(imgs_normalized[i])) / (np.max(imgs_normalized[i])-np.min(imgs_normalized[i])))
    return imgs_normalized


## Temporary
class isic_loader(Dataset):
    """ dataset class for Brats datasets
    """
    def __init__(self, path_Data, train = True, Test = False):
        super(isic_loader, self)
        self.train = train
        if train:
          self.data   = np.load(path_Data+'data_train.npy')
          self.mask   = np.load(path_Data+'mask_train.npy')
        else:
          if Test:
            self.data   = np.load(path_Data+'data_test.npy')
            self.mask   = np.load(path_Data+'mask_test.npy')
          else:
            self.data   = np.load(path_Data+'data_val.npy')
            self.mask   = np.load(path_Data+'mask_val.npy')          
        
        self.data   = dataset_normalized(self.data)
        self.mask   = np.expand_dims(self.mask, axis=3)
        self.mask   = self.mask/255.
        

    def __getitem__(self, indx):
        img = self.data[indx]
        seg = self.mask[indx]
        if self.train:
            if random.random() > 0.5:
                img, seg = self.random_rot_flip(img, seg)
            if random.random() > 0.5:
                img, seg = self.random_rotate(img, seg)
        
        seg = torch.tensor(seg.copy())
        img = torch.tensor(img.copy())
        img = img.permute( 2, 0, 1)
        seg = seg.permute( 2, 0, 1)
      #  print(seg)

        return img, seg
    
    def random_rot_flip(self,image, label):
        k = np.random.randint(0, 4)
        image = np.rot90(image, k)
        label = np.rot90(label, k)
        axis = np.random.randint(0, 2)
        image = np.flip(image, axis=axis).copy()
        label = np.flip(label, axis=axis).copy()
        return image, label
    
    def random_rotate(self,image, label):
        angle = np.random.randint(20, 80)
        image = ndimage.rotate(image, angle, order=0, reshape=False)
        label = ndimage.rotate(label, angle, order=0, reshape=False)
        return image, label


               
    def __len__(self):
        return len(self.data)