From 0a32fc3bb36b1a37e6514ba8e5ae2bfa0e79a09a Mon Sep 17 00:00:00 2001
From: Alexander Alekhin <alexander.a.alekhin@gmail.com>
Date: Sun, 22 Mar 2020 02:18:37 +0000
Subject: [PATCH] stereo: smallRegionRemoval() is not inplace

---
 modules/stereo/src/matching.hpp           | 13 ++++++++++---
 modules/stereo/src/stereo_binary_bm.cpp   |  2 +-
 modules/stereo/src/stereo_binary_sgbm.cpp |  2 +-
 3 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/modules/stereo/src/matching.hpp b/modules/stereo/src/matching.hpp
index 10d30a636..c57546062 100644
--- a/modules/stereo/src/matching.hpp
+++ b/modules/stereo/src/matching.hpp
@@ -493,6 +493,7 @@ namespace cv
             template <typename T>
             void smallRegionRemoval(const Mat &currentMap, int t, Mat &out)
             {
+                CV_Assert(currentMap.data != out.data && "inplace is not supported");
                 CV_Assert(currentMap.cols == out.cols);
                 CV_Assert(currentMap.rows == out.rows);
                 CV_Assert(t >= 0);
@@ -511,16 +512,22 @@ namespace cv
                 int speckle_size = 0;
                 st = 0;
                 dr = 0;
-                for (int i = 1; i < height - 1; i++)
+                for (int i = 0; i < height; i++)
                 {
                     int iw = i * width;
-                    for (int j = 1; j < width - 1; j++)
+                    for (int j = 0; j < width; j++)
                     {
+                        if (i < 1 || i >= height - 1 || j < 1 || j >= width - 1)
+                        {
+                            outputMap[iw + j] = 0;
+                            continue;
+                        }
+
                         if (map[iw + j] != 0)
                         {
                             outputMap[iw + j] = map[iw + j];
                         }
-                        else if (map[iw + j] == 0)
+                        else // if (map[iw + j] == 0)
                         {
                             T nr = 1;
                             T avg = 0;
diff --git a/modules/stereo/src/stereo_binary_bm.cpp b/modules/stereo/src/stereo_binary_bm.cpp
index d6e280bdf..ba4cb007e 100644
--- a/modules/stereo/src/stereo_binary_bm.cpp
+++ b/modules/stereo/src/stereo_binary_bm.cpp
@@ -402,7 +402,7 @@ namespace cv
 
                 if(params.regionRemoval == CV_SPECKLE_REMOVAL_AVG_ALGORITHM)
                 {
-                    smallRegionRemoval<uint8_t>(disp0,params.speckleWindowSize,disp0);
+                    smallRegionRemoval<uint8_t>(disp0.clone(),params.speckleWindowSize,disp0);
                 }
                 else if(params.regionRemoval == CV_SPECKLE_REMOVAL_ALGORITHM)
                 {
diff --git a/modules/stereo/src/stereo_binary_sgbm.cpp b/modules/stereo/src/stereo_binary_sgbm.cpp
index ded25c7c9..2b23cccf3 100644
--- a/modules/stereo/src/stereo_binary_sgbm.cpp
+++ b/modules/stereo/src/stereo_binary_sgbm.cpp
@@ -697,7 +697,7 @@ namespace cv
                     aux.create(height,width,CV_16S);
                     Median1x9Filter<short>(disp, aux);
                     Median9x1Filter<short>(aux,disp);
-                    smallRegionRemoval<short>(disp, params.speckleWindowSize, disp);
+                    smallRegionRemoval<short>(disp.clone(), params.speckleWindowSize, disp);
                 }
                 else if(params.regionRemoval == CV_SPECKLE_REMOVAL_ALGORITHM)
                 {