From 2db502a9cce1f6ff6605805c12c5d6bb90da91cd Mon Sep 17 00:00:00 2001
From: Luke Campagnola <luke.campagnola@gmail.com>
Date: Thu, 16 Nov 2017 09:25:27 -0800
Subject: [PATCH] Fix bug when switching level mode

---
 pyqtgraph/graphicsItems/HistogramLUTItem.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/pyqtgraph/graphicsItems/HistogramLUTItem.py b/pyqtgraph/graphicsItems/HistogramLUTItem.py
index e6d692e6..90e2e790 100644
--- a/pyqtgraph/graphicsItems/HistogramLUTItem.py
+++ b/pyqtgraph/graphicsItems/HistogramLUTItem.py
@@ -293,7 +293,6 @@ class HistogramLUTItem(GraphicsWidget):
         
         self.levelMode = mode
         self._showRegions()
-        self.imageChanged()
         
         # do our best to preserve old levels
         if mode == 'mono':
@@ -302,7 +301,12 @@ class HistogramLUTItem(GraphicsWidget):
         else:
             levels = [oldLevels] * 4
             self.setLevels(rgba=levels)
+            
+        # force this because calling self.setLevels might not set the imageItem
+        # levels if there was no change to the region item
+        self.imageItem().setLevels(self.getLevels())
         
+        self.imageChanged()
         self.update()
 
     def _showRegions(self):