From 1f4f50b9dc2e4713abb6a5dee5dc4d0e8a766685 Mon Sep 17 00:00:00 2001
From: Vladislav Sovrasov <sovrasov.vlad@gmail.com>
Date: Tue, 18 Oct 2016 14:16:14 +0300
Subject: [PATCH] findContours: integrate workaroung to allow contours
 detection on image border

---
 modules/imgproc/src/contours.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/modules/imgproc/src/contours.cpp b/modules/imgproc/src/contours.cpp
index d59c5a17df..427cd050b1 100644
--- a/modules/imgproc/src/contours.cpp
+++ b/modules/imgproc/src/contours.cpp
@@ -1878,13 +1878,14 @@ void cv::findContours( InputOutputArray _image, OutputArrayOfArrays _contours,
 
     CV_Assert(_contours.empty() || (_contours.channels() == 2 && _contours.depth() == CV_32S));
 
-    Mat image = _image.getMat();
+    Mat image;
+    copyMakeBorder(_image, image, 1, 1, 1, 1, BORDER_CONSTANT, Scalar(0));
     MemStorage storage(cvCreateMemStorage());
     CvMat _cimage = image;
     CvSeq* _ccontours = 0;
     if( _hierarchy.needed() )
         _hierarchy.clear();
-    cvFindContours(&_cimage, storage, &_ccontours, sizeof(CvContour), mode, method, offset);
+    cvFindContours(&_cimage, storage, &_ccontours, sizeof(CvContour), mode, method, offset + Point(-1, -1));
     if( !_ccontours )
     {
         _contours.clear();