From dcc2512f581f56fb887ae955ebe828071dee7b92 Mon Sep 17 00:00:00 2001
From: Naer Chang <naer.chang@gmail.com>
Date: Sat, 14 Mar 2015 02:56:29 -0400
Subject: [PATCH] issue 3710

added a check to prevent illegal access to operator[] when vector is empty
---
 modules/objdetect/src/cascadedetect.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/modules/objdetect/src/cascadedetect.cpp b/modules/objdetect/src/cascadedetect.cpp
index 1c0bbf1b0b..e34d5f6efa 100644
--- a/modules/objdetect/src/cascadedetect.cpp
+++ b/modules/objdetect/src/cascadedetect.cpp
@@ -1268,7 +1268,7 @@ void CascadeClassifierImpl::detectMultiScaleNoGrouping( InputArray _image, std::
         scales.push_back((float)factor);
     }
 
-    if( !featureEvaluator->setImage(gray, scales) )
+	if ( scales.size() == 0 || !featureEvaluator->setImage(gray, scales) )
         return;
 
     // OpenCL code