From dd8589c3523ade76ddb887c92ebbec78b17d70fe Mon Sep 17 00:00:00 2001
From: StevenPuttemans <steven.puttemans@kuleuven.be>
Date: Thu, 6 Aug 2015 14:59:15 +0200
Subject: [PATCH] change as suggested by original programmer and user of ecc
 software

---
 modules/video/src/ecc.cpp | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/modules/video/src/ecc.cpp b/modules/video/src/ecc.cpp
index cc08ac005c..d11419e402 100644
--- a/modules/video/src/ecc.cpp
+++ b/modules/video/src/ecc.cpp
@@ -298,11 +298,7 @@ static void update_warping_matrix_ECC (Mat& map_matrix, const Mat& update, const
     }
     if (motionType == MOTION_EUCLIDEAN) {
         double new_theta = updatePtr[0];
-        if (mapPtr[3]>0)
-            new_theta += acos(mapPtr[0]);
-
-        if (mapPtr[3]<0)
-            new_theta -= acos(mapPtr[0]);
+        new_theta += asin(mapPtr[3]);
 
         mapPtr[2] += updatePtr[1];
         mapPtr[5] += updatePtr[2];