diff --git a/OBIA/OBIABase.py b/OBIA/OBIABase.py
index 113697a5f6bd6ed90c4f869971e627bb5ce2002a..ff0bd8d8f78e1a9a116e2411c1190b0a1f9ee6be 100644
--- a/OBIA/OBIABase.py
+++ b/OBIA/OBIABase.py
@@ -332,12 +332,29 @@ class OBIABase:
         obj.SetParameterOutputImagePixelType('out', otb.ImagePixelType_uint16)
         obj.ExecuteAndWriteOutput()
 
-    def true_pred_bypixel(self, labels, predicted_classes): #TOBECHANGED
-        pred_c = np.zeros(np.max(self.ref_obj_layer)+1)
+    def true_pred_bypixel(self, labels, predicted_classes):
+        pred_c = np.zeros(np.max(self.ref_db['orig_label']).astype(int)+1)
         pred_c[labels] = predicted_classes
-        pred = pred_c[self.ref_obj_layer]
+        support = []
+        for tn, t in self.tiled_objects(on_ref=True):
+            support.append(t[np.isin(t, labels)])
+        support = np.concatenate(support)
+        pred = pred_c[support]
         true_c = np.zeros(np.max(self.ref_db['orig_label']).astype(int)+1)
         # ATTENTION: works if "labels" is sorted (as provided by get_reference_...)
         true_c[labels] = self.ref_db.loc[self.ref_db['orig_label'].isin(labels),'class'].to_numpy(dtype=int)
-        true = true_c[self.ref_obj_layer]
+        true = true_c[support]
         return pred[pred>0], true[pred>0]
+
+    def tiled_objects(self, on_ref=False):
+        assert(self.tiles is not None)
+        idx = -1 if on_ref else 0
+        r = otb.itkRegion()
+        for tn, t in self.tiles.items():
+            r['index'][0], r['index'][1] = t[0], t[1]
+            r['size'][0], r['size'][1] = t[2], t[3]
+            self.ref_obj_layer_pipe[idx].PropagateRequestedRegion('out', r)
+            arr = self.ref_obj_layer_pipe[idx].GetImageAsNumpyArray('out').astype(np.uint32)
+            yield tn, arr
+
+