implement binarization methods

requirements.txt

@@ -10,3 +10,4 @@ metrics==0.3.3
 tf_keras_vis==0.8.5
 elasticdeform==0.5.0
 blinker==1.4
+scikit-image==0.22.0

src/data_generator.py

@@ -6,9 +6,11 @@
 # > Local dependencies
 
 # > Third party libraries
+import cv2
 import tensorflow as tf
 import elasticdeform.tf as etf
 import tensorflow_addons as tfa
+from skimage.filters import threshold_otsu, threshold_sauvola
 
 class DataGenerator(tf.keras.utils.Sequence):
 
@@ -44,8 +46,26 @@ def elastic_transform(self, original):
         X_deformed = etf.deform_grid(original, displacement_val, axis=(0, 1), order=3)
         return X_deformed
 
-    def load_images(self, imagePath):
-        image = tf.io.read_file(imagePath[0])
+    def binarize_sauvola(self, tensor):
+        np_array = tensor.numpy()
+        window_size = 51
+
+        sauvola_thresh = threshold_sauvola(np_array, window_size=window_size)
+        binary_sauvola = (np_array > sauvola_thresh) * 1
+
+        return tf.convert_to_tensor(binary_sauvola)
+
+    def binarize_otsu(self, tensor):
+        np_array = tensor.numpy()
+
+        np_array = cv2.cvtColor(np_array, cv2.COLOR_RGB2GRAY)
+
+        otsu_threshold = threshold_otsu(np_array)
+
+        return tf.convert_to_tensor((np_array > otsu_threshold) * 1)
+
+    def load_images(self, image_path):
+        image = tf.io.read_file(image_path[0])
         image = tf.image.decode_png(image, channels=self.channels)
         image = tf.image.resize(image, (self.height, 99999), preserve_aspect_ratio=True) / 255.0
         if self.distort_jpeg: