diff --git a/pyqtgraph/exporters/ImageExporter.py b/pyqtgraph/exporters/ImageExporter.py
index 69c02508..e600afc9 100644
--- a/pyqtgraph/exporters/ImageExporter.py
+++ b/pyqtgraph/exporters/ImageExporter.py
@@ -58,17 +58,17 @@ class ImageExporter(Exporter):
                     filter.insert(0, p)
             self.fileSaveDialog(filter=filter)
             return
-            
-        targetRect = QtCore.QRect(0, 0, self.params['width'], self.params['height'])
-        sourceRect = self.getSourceRect()
-        
-        
-        #self.png = QtGui.QImage(targetRect.size(), QtGui.QImage.Format_ARGB32)
-        #self.png.fill(pyqtgraph.mkColor(self.params['background']))
-        w, h = self.params['width'], self.params['height']
+
+        w = int(self.params['width'])
+        h = int(self.params['height'])
         if w == 0 or h == 0:
-            raise Exception("Cannot export image with size=0 (requested export size is %dx%d)" % (w,h))
-        bg = np.empty((self.params['height'], self.params['width'], 4), dtype=np.ubyte)
+            raise Exception("Cannot export image with size=0 (requested "
+                            "export size is %dx%d)" % (w, h))
+
+        targetRect = QtCore.QRect(0, 0, w, h)
+        sourceRect = self.getSourceRect()
+
+        bg = np.empty((h, w, 4), dtype=np.ubyte)
         color = self.params['background']
         bg[:,:,0] = color.blue()
         bg[:,:,1] = color.green()