From f4123a4e36c7a82061f6024c61245aa9ef144950 Mon Sep 17 00:00:00 2001
From: Martin Zackrisson <martin.zackrisson@gmail.com>
Date: Mon, 30 May 2016 11:29:35 +0200
Subject: [PATCH] Added missing documentation about raised error

---
 skimage/filters/thresholding.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/skimage/filters/thresholding.py b/skimage/filters/thresholding.py
index 285af6d4..ccd88be4 100644
--- a/skimage/filters/thresholding.py
+++ b/skimage/filters/thresholding.py
@@ -110,6 +110,12 @@ def threshold_otsu(image, nbins=256):
     threshold : float
         Upper threshold value. All pixels intensities that less or equal of
         this value assumed as foreground.
+        
+    Raises
+    ------
+    
+    ValueError
+         If `image` only contains a single grayscale value.
 
     References
     ----------