Update lanenet_back_end.py

add focal loss.
SEURickyFang · Jul 9, 2020 · b7c431c · b7c431c
1 parent c1246f4
commit b7c431c
Showing 1 changed file with 19 additions and 2 deletions.
diff --git a/lanenet_model/lanenet_back_end.py b/lanenet_model/lanenet_back_end.py
@@ -75,7 +75,20 @@ def _multi_category_focal_loss(cls, onehot_labels, logits, classes_weights, gamm
         :param gamma:
         :return:
         """
-        raise NotImplementedError('Func has not been implemented')
+        epsilon = 1.e-7
+        alpha = tf.multiply(onehot_labels, classes_weights)
+        alpha = tf.cast(alpha, tf.float32)
+        gamma = float(gamma)
+        y_true = tf.cast(onehot_labels, tf.float32)
+        y_pred = tf.nn.softmax(logits, dim=-1)
+        y_pred = tf.clip_by_value(y_pred, epsilon, 1. - epsilon)
+        y_t = tf.multiply(y_true, y_pred) + tf.multiply(1-y_true, 1-y_pred)
+        ce = -tf.log(y_t)
+        weight = tf.pow(tf.subtract(1., y_t), gamma)
+        fl = tf.multiply(tf.multiply(weight, ce), alpha)
+        loss = tf.reduce_mean(fl)
+
+        return loss
 
     def compute_loss(self, binary_seg_logits, binary_label,
                      instance_seg_logits, instance_label,
@@ -122,7 +135,11 @@ def compute_loss(self, binary_seg_logits, binary_label,
                         classes_weights=inverse_weights
                     )
                 elif self._binary_loss_type == 'focal':
-                    raise NotImplementedError
+                    binary_segmenatation_loss = self._multi_category_focal_loss(
+                    onehot_labels=binary_label_onehot,
+                    logits=binary_seg_logits,
+                    classes_weights=inverse_weights
+                    )
                 else:
                     raise NotImplementedError