diff --git a/load.py b/load.py
new file mode 100644
index 0000000..a981f03
--- /dev/null
+++ b/load.py
@@ -0,0 +1,47 @@
+import os
+import random
+import numpy as np
+from PIL import Image
+from functools import partial
+from utils import resize_and_crop, get_square
+
+
+def get_ids(dir):
+    """Returns a list of the ids in the directory"""
+    return (f[:-4] for f in os.listdir(dir))
+
+def split_ids(ids, n=2):
+    """Split each id in n, creating n tuples (id, k) for each id"""
+    return ((id, i) for i in range(n) for id in ids)
+
+def shuffle_ids(ids):
+    """Returns a shuffle list od the ids"""
+    lst = list(ids)
+    random.shuffle(lst)
+    return lst
+
+def to_cropped_imgs(ids, dir, suffix):
+    """From a list of tuples, returns the correct cropped img (left or right)"""
+    for id, pos in ids:
+        im = resize_and_crop(Image.open(dir + id + suffix))
+        yield get_square(im, pos)
+
+
+
+def get_imgs_and_masks():
+    """From the list of ids, return the couples (img, mask)"""
+    dir_img = 'data/train/'
+    dir_mask = 'data/train_masks/'
+
+    ids = get_ids(dir_img)
+    ids = split_ids(ids)
+    ids = shuffle_ids(ids)
+
+    imgs = to_cropped_imgs(ids, dir_img, '.jpg')
+
+    # need to transform from HWC to CHW
+    imgs_switched = map(partial(np.transpose, axes=[2, 0, 1]), imgs)
+
+    masks = to_cropped_imgs(ids, dir_mask, '_mask.gif')
+
+    return zip(imgs_switched, masks)
diff --git a/utils.py b/utils.py
index 2664254..9732526 100644
--- a/utils.py
+++ b/utils.py
@@ -1,16 +1,18 @@
 import PIL
+import numpy as np
 
-def split_into_squares(img):
-    """Extract a left and a right square from ndarray"""
+def get_square(img, pos):
+    """Extract a left or a right square from PILimg"""
     """shape : (H, W, C))"""
+    img = np.array(img)
+
     h = img.shape[0]
     w = img.shape[1]
 
-
-    left = img[:, :h]
-    right = img[:, -h:]
-
-    return left, right
+    if pos == 0:
+        return img[:, :h]
+    else:
+        return img[:, -h:]
 
 def resize_and_crop(pilimg, scale=0.5, final_height=640):
     w = pilimg.size[0]