diff --git a/skimage/util/dtype.py b/skimage/util/dtype.py
index 2b971b9c..eef7f478 100644
--- a/skimage/util/dtype.py
+++ b/skimage/util/dtype.py
@@ -155,7 +155,7 @@ def convert(image, dtype, force_copy=False, uniform=False):
         if kind_in in "fi":
             sign_loss()
         prec_loss()
-        return image > dtype_in(0)
+        return image > dtype_in(dtype_range[dtype_in][1] / 2)
 
     if kind_in == 'b':
         # from binary image, to float and to integer