From 4db1e1b83c5c2b2573dcc4d4124cf0ddafb674c3 Mon Sep 17 00:00:00 2001
From: Kemal Eren <kemal@kemaleren.com>
Date: Mon, 7 Oct 2013 23:17:52 -0700
Subject: [PATCH] handle case when there are no labels

---
 skimage/color/colorlabel.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/skimage/color/colorlabel.py b/skimage/color/colorlabel.py
index b87af980..9b878ecc 100644
--- a/skimage/color/colorlabel.py
+++ b/skimage/color/colorlabel.py
@@ -101,6 +101,9 @@ def label2rgb(label, image=None, colors=None, alpha=0.3,
             bg_color = _rgb_vector(bg_color)
             color_cycle = itertools.chain(bg_color, color_cycle)
 
+    if len(labels) == 0:
+        return img_layer
+
     label_to_color = np.zeros((max(labels) + 1, 3))
     for lab, c in zip(labels, color_cycle):
         label_to_color[lab] = c