diff --git a/icons/prev.png b/icons/prev.png
new file mode 100644
index 00000000..31b45451
Binary files /dev/null and b/icons/prev.png differ
diff --git a/labelImg.py b/labelImg.py
index f633ecde..8a0b4b31 100755
--- a/labelImg.py
+++ b/labelImg.py
@@ -65,13 +65,17 @@ class MainWindow(QMainWindow, WindowMixin):
         # Whether we need to save or not.
         self.dirty = False
 
+        # Enble auto saving if pressing next
+        self.autoSaving = True
         self._noSelectionSlot = False
         self._beginner = True
         self.screencastViewer = "firefox"
         self.screencast = "https://youtu.be/p0nR2YsCY_U"
 
         # Main widgets and related state.
-        self.labelDialog = LabelDialog(parent=self)
+        predefined_classes = ['person', 'dog']
+        self.labelHist = predefined_classes
+        self.labelDialog = LabelDialog(parent=self, listItem=self.labelHist)
 
         self.labelList = QListWidget()
         self.itemsToShapes = {}
@@ -822,8 +826,14 @@ class MainWindow(QMainWindow, WindowMixin):
 
 
     def openNextImg(self, _value=False):
+        # Proceding next image without dialog if having any label
+        if self.autoSaving is True and self.defaultSaveDir is not None:
+            if self.dirty is True and self.hasLabels():
+                self.saveFile()
+
         if not self.mayContinue():
             return
+
         if len(self.mImgList) <= 0:
             return
         filename = self.mImgList.pop(0)
diff --git a/libs/labelDialog.py b/libs/labelDialog.py
index b9da6308..7f2b8992 100644
--- a/libs/labelDialog.py
+++ b/libs/labelDialog.py
@@ -49,3 +49,4 @@ class LabelDialog(QDialog):
     def listItemClick(self, tQListWidgetItem):
         text = tQListWidgetItem.text().trimmed()
         self.edit.setText(text)
+        self.validate()
diff --git a/libs/labelFile.py b/libs/labelFile.py
index aa86fe08..80108980 100644
--- a/libs/labelFile.py
+++ b/libs/labelFile.py
@@ -87,8 +87,18 @@ class LabelFile(object):
         for p in points:
             x = p[0]
             y = p[1]
-            xmin = min(x,xmin) 
-            ymin = min(y,ymin) 
-            xmax = max(x,xmax) 
-            ymax = max(y,ymax) 
+            xmin = min(x,xmin)
+            ymin = min(y,ymin)
+            xmax = max(x,xmax)
+            ymax = max(y,ymax)
+
+        # Martin Kersner, 2015/11/12
+        # 0-valued coordinates of BB caused an error while
+        # training faster-rcnn object detector.
+        if (xmin < 1):
+            xmin = 1
+
+        if (ymin < 1):
+            ymin = 1
+
         return (int(xmin), int(ymin), int(xmax), int(ymax))