From 044d38a051703b96525027474c2a7e3de7c85025 Mon Sep 17 00:00:00 2001
From: Vadim Pisarevsky <vadim.pisarevsky@itseez.com>
Date: Tue, 9 Oct 2012 22:38:04 +0400
Subject: [PATCH] expanded cv::threshold parallelization to other threading
 frameworks; fixed potential bug with unprocessed bottom of the image; fixed
 build problem in stitching

---
 modules/imgproc/src/thresh.cpp     | 34 +++++++++++++-----------------
 samples/cpp/stitching_detailed.cpp |  1 +
 2 files changed, 16 insertions(+), 19 deletions(-)

diff --git a/modules/imgproc/src/thresh.cpp b/modules/imgproc/src/thresh.cpp
index 1fb4847e8..06bd02af5 100644
--- a/modules/imgproc/src/thresh.cpp
+++ b/modules/imgproc/src/thresh.cpp
@@ -661,7 +661,7 @@ getThreshVal_Otsu_8u( const Mat& _src )
     return max_val;
 }
 
-class ThresholdRunner
+class ThresholdRunner : public ParallelLoopBody
 {
 public:
     ThresholdRunner(Mat _src, Mat _dst, int _nStripes, double _thresh, double _maxval, int _thresholdType)
@@ -676,10 +676,11 @@ public:
         thresholdType = _thresholdType;
     }
 
-    void operator () ( const BlockedRange& range ) const
+    void operator () ( const Range& range ) const
     {
-        int row0 = std::min(cvRound(range.begin() * src.rows / nStripes), src.rows);
-        int row1 = std::min(cvRound(range.end() * src.rows / nStripes), src.rows);
+        int row0 = std::min(cvRound(range.start * src.rows / nStripes), src.rows);
+        int row1 = range.end >= nStripes ? src.rows :
+            std::min(cvRound(range.end * src.rows / nStripes), src.rows);
 
         /*if(0)
             printf("Size = (%d, %d), range[%d,%d), row0 = %d, row1 = %d\n",
@@ -756,12 +757,10 @@ double cv::threshold( InputArray _src, OutputArray _dst, double thresh, double m
             }
             else
                 src.copyTo(dst);
+            return thresh;
         }
-        else
-        {
-            parallel_for(BlockedRange(0, nStripes),
-                         ThresholdRunner(src, dst, nStripes, (uchar)ithresh, (uchar)imaxval, type));
-        }
+        thresh = ithresh;
+        maxval = imaxval;
     }
     else if( src.depth() == CV_16S )
     {
@@ -785,21 +784,18 @@ double cv::threshold( InputArray _src, OutputArray _dst, double thresh, double m
             }
             else
                 src.copyTo(dst);
+            return thresh;
         }
-        else
-        {
-            parallel_for(BlockedRange(0, nStripes),
-                         ThresholdRunner(src, dst, nStripes, (short)ithresh, (short)imaxval, type));
-        }
+        thresh = ithresh;
+        maxval = imaxval;
     }
     else if( src.depth() == CV_32F )
-    {
-        parallel_for(BlockedRange(0, nStripes),
-                     ThresholdRunner(src, dst, nStripes, (float)thresh, (float)maxval, type));
-    }
+        ;
     else
         CV_Error( CV_StsUnsupportedFormat, "" );
-
+        
+    parallel_for_(Range(0, nStripes),
+                  ThresholdRunner(src, dst, nStripes, thresh, maxval, type));
     return thresh;
 }
 
diff --git a/samples/cpp/stitching_detailed.cpp b/samples/cpp/stitching_detailed.cpp
index 1e461174d..cbd050d7c 100644
--- a/samples/cpp/stitching_detailed.cpp
+++ b/samples/cpp/stitching_detailed.cpp
@@ -41,6 +41,7 @@
 //
 //M*/
 
+#include <iostream>
 #include <fstream>
 #include <string>
 #include "opencv2/opencv_modules.hpp"