From a81374c1d7f139513d7ff7e2fbafea0e3a30615d Mon Sep 17 00:00:00 2001
From: ttagu99 <ttagu99@gmail.com>
Date: Tue, 14 Apr 2015 10:01:53 +0900
Subject: [PATCH] findcontour_example check image empty

---
 .../tutorial_code/ShapeDescriptors/findContours_demo.cpp | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/samples/cpp/tutorial_code/ShapeDescriptors/findContours_demo.cpp b/samples/cpp/tutorial_code/ShapeDescriptors/findContours_demo.cpp
index bff125f2f0..4db93494c8 100644
--- a/samples/cpp/tutorial_code/ShapeDescriptors/findContours_demo.cpp
+++ b/samples/cpp/tutorial_code/ShapeDescriptors/findContours_demo.cpp
@@ -26,8 +26,13 @@ void thresh_callback(int, void* );
  */
 int main( int, char** argv )
 {
-  /// Load source image and convert it to gray
-  src = imread( argv[1], 1 );
+  /// Load source image
+  src = imread(argv[1]);
+  if (src.empty())
+  {
+    cerr << "No image supplied ..." << endl;
+    return -1;
+  }
 
   /// Convert image to gray and blur it
   cvtColor( src, src_gray, COLOR_BGR2GRAY );