From b9c2d88e69b507ec05efc2085305696ef279b919 Mon Sep 17 00:00:00 2001
From: Utkarsh Sinha <sinha.utkarsh1990@gmail.com>
Date: Mon, 10 Apr 2017 20:43:33 -0700
Subject: [PATCH] If the user passes an empty output matrix, initialize it to
 identity.

---
 modules/video/src/ecc.cpp | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/modules/video/src/ecc.cpp b/modules/video/src/ecc.cpp
index d11419e402..377b775072 100644
--- a/modules/video/src/ecc.cpp
+++ b/modules/video/src/ecc.cpp
@@ -325,6 +325,16 @@ double cv::findTransformECC(InputArray templateImage,
     CV_Assert(!src.empty());
     CV_Assert(!dst.empty());
 
+    // If the user passed an un-initialized warpMatrix, initialize to identity
+    if(map.empty()) {
+        int rowCount = 2;
+        if(motionType == MOTION_HOMOGRAPHY)
+            rowCount = 3;
+
+        warpMatrix.create(rowCount, 3, CV_32FC1);
+        map = warpMatrix.getMat();
+        map = Mat::eye(rowCount, 3, CV_32F);
+    }
 
     if( ! (src.type()==dst.type()))
         CV_Error( Error::StsUnmatchedFormats, "Both input images must have the same data type" );
-- 
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