From 81e49b6686fc7263df5d51f28827baac136db022 Mon Sep 17 00:00:00 2001
From: Tony S Yu <tsyu80@gmail.com>
Date: Thu, 13 Sep 2012 21:37:52 -0400
Subject: [PATCH] DOC: Fix docstring note about conversion range

---
 skimage/util/dtype.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/skimage/util/dtype.py b/skimage/util/dtype.py
index eef7f478..d2a0dd61 100644
--- a/skimage/util/dtype.py
+++ b/skimage/util/dtype.py
@@ -360,7 +360,8 @@ def img_as_bool(image, force_copy=False):
 
     Notes
     -----
-    All non-zero elements are treated as True.
+    The upper half of the input dtype's positive range is True, and the lower
+    half is False. All negative values (if present) are False.
 
     """
     return convert(image, np.bool_, force_copy)