From 152c5d393ffda15c92943b1f53f5266b1f26b08a Mon Sep 17 00:00:00 2001
From: Luke Campagnola <luke.campagnola@gmail.com>
Date: Wed, 7 Sep 2016 17:56:00 -0700
Subject: [PATCH] Fixed bool / monochrome image display, added more unit tests

---
 pyqtgraph/functions.py                          |  2 ++
 pyqtgraph/graphicsItems/HistogramLUTItem.py     |  4 ++--
 pyqtgraph/graphicsItems/ImageItem.py            |  6 ++++--
 pyqtgraph/graphicsItems/tests/test_ImageItem.py | 12 ++++++++++++
 pyqtgraph/tests/image_testing.py                |  2 +-
 5 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/pyqtgraph/functions.py b/pyqtgraph/functions.py
index 9199fea7..d79c350f 100644
--- a/pyqtgraph/functions.py
+++ b/pyqtgraph/functions.py
@@ -959,6 +959,8 @@ def makeARGB(data, lut=None, levels=None, scale=None, useRGBA=False):
         elif data.dtype.kind == 'i':
             s = 2**(data.itemsize*8 - 1)
             levels = np.array([-s, s-1])
+        elif data.dtype.kind == 'b':
+            levels = np.array([0,1])
         else:
             raise Exception('levels argument is required for float input types')
     if not isinstance(levels, np.ndarray):
diff --git a/pyqtgraph/graphicsItems/HistogramLUTItem.py b/pyqtgraph/graphicsItems/HistogramLUTItem.py
index c46dbbbe..31764250 100644
--- a/pyqtgraph/graphicsItems/HistogramLUTItem.py
+++ b/pyqtgraph/graphicsItems/HistogramLUTItem.py
@@ -179,8 +179,8 @@ class HistogramLUTItem(GraphicsWidget):
         return self.lut
 
     def regionChanged(self):
-        #if self.imageItem is not None:
-            #self.imageItem.setLevels(self.region.getRegion())
+        if self.imageItem() is not None:
+            self.imageItem().setLevels(self.region.getRegion())
         self.sigLevelChangeFinished.emit(self)
         #self.update()
 
diff --git a/pyqtgraph/graphicsItems/ImageItem.py b/pyqtgraph/graphicsItems/ImageItem.py
index 26897cf0..3d45ad77 100644
--- a/pyqtgraph/graphicsItems/ImageItem.py
+++ b/pyqtgraph/graphicsItems/ImageItem.py
@@ -379,12 +379,14 @@ class ImageItem(GraphicsObject):
                 eflsize = 2**(image.itemsize*8)
                 ind = np.arange(eflsize)
                 minlev, maxlev = levels
+                levdiff = maxlev - minlev
+                levdiff = 1 if levdiff == 0 else levdiff  # don't allow division by 0
                 if lut is None:
-                    efflut = fn.rescaleData(ind, scale=255./(maxlev-minlev), 
+                    efflut = fn.rescaleData(ind, scale=255./levdiff, 
                                             offset=minlev, dtype=np.ubyte)
                 else:
                     lutdtype = np.min_scalar_type(lut.shape[0]-1)
-                    efflut = fn.rescaleData(ind, scale=(lut.shape[0]-1)/(maxlev-minlev),
+                    efflut = fn.rescaleData(ind, scale=(lut.shape[0]-1)/levdiff,
                                             offset=minlev, dtype=lutdtype, clip=(0, lut.shape[0]-1))
                     efflut = lut[efflut]
                 
diff --git a/pyqtgraph/graphicsItems/tests/test_ImageItem.py b/pyqtgraph/graphicsItems/tests/test_ImageItem.py
index e247abe3..4f310bc3 100644
--- a/pyqtgraph/graphicsItems/tests/test_ImageItem.py
+++ b/pyqtgraph/graphicsItems/tests/test_ImageItem.py
@@ -60,6 +60,18 @@ def test_ImageItem(transpose=False):
     img.setLevels([127, 128])
     assertImageApproved(w, 'imageitem/gradient_mono_byte_levels', 'Mono byte gradient w/ levels to isolate diagonal.')
 
+    # test monochrome image
+    data = np.zeros((10, 10), dtype='uint8')
+    data[:5,:5] = 1
+    data[5:,5:] = 1
+    img.setImage(data)
+    assertImageApproved(w, 'imageitem/monochrome', 'Ubyte image with only 0,1 values.')
+    
+    # test bool
+    data = data.astype(bool)
+    img.setImage(data)
+    assertImageApproved(w, 'imageitem/bool', 'Boolean mask.')
+
     # test RGBA byte
     data = np.zeros((100, 100, 4), dtype='ubyte')
     data[..., 0] = np.linspace(0, 255, 100).reshape(100, 1)
diff --git a/pyqtgraph/tests/image_testing.py b/pyqtgraph/tests/image_testing.py
index 135ef59b..628bde1a 100644
--- a/pyqtgraph/tests/image_testing.py
+++ b/pyqtgraph/tests/image_testing.py
@@ -42,7 +42,7 @@ Procedure for unit-testing with images:
 # pyqtgraph should be tested against. When adding or changing test images,
 # create and push a new tag and update this variable. To test locally, begin
 # by creating the tag in your ~/.pyqtgraph/test-data repository.
-testDataTag = 'test-data-5'
+testDataTag = 'test-data-6'
 
 
 import time