fixed unnecessary reconstruction in seamlessclone

fixed unnecessary reconstruction in seamlessclone by using only the
required rectangular area in input images

modules/photo/src/seamless_cloning.cpp

@@ -56,15 +56,13 @@ void cv::seamlessClone(InputArray _src, InputArray _dst, InputArray _mask, Point
     const Mat mask = _mask.getMat();
     _blend.create(dest.size(), CV_8UC3);
     Mat blend = _blend.getMat();
+    dest.copyTo(blend);
 
     int minx = INT_MAX, miny = INT_MAX, maxx = INT_MIN, maxy = INT_MIN;
     int h = mask.size().height;
     int w = mask.size().width;
 
     Mat gray = Mat(mask.size(),CV_8UC1);
-    Mat dst_mask = Mat::zeros(dest.size(),CV_8UC1);
-    Mat cs_mask = Mat::zeros(src.size(),CV_8UC3);
-    Mat cd_mask = Mat::zeros(dest.size(),CV_8UC3);
 
     if(mask.channels() == 3)
         cvtColor(mask, gray, COLOR_BGR2GRAY );
@@ -100,19 +98,16 @@ void cv::seamlessClone(InputArray _src, InputArray _dst, InputArray _mask, Point
     Rect roi_d(minyd,minxd,leny,lenx);
     Rect roi_s(miny,minx,leny,lenx);
 
-    Mat destinationROI = dst_mask(roi_d);
-    Mat sourceROI = cs_mask(roi_s);
+    Mat destinationROI = dest(roi_d).clone();
 
-    gray(roi_s).copyTo(destinationROI);
+    Mat sourceROI = Mat::zeros(leny, lenx, src.type());
     src(roi_s).copyTo(sourceROI,gray(roi_s));
-    src(roi_s).copyTo(patch, gray(roi_s));
-
-    destinationROI = cd_mask(roi_d);
-    cs_mask(roi_s).copyTo(destinationROI);
 
+    Mat maskROI = gray(roi_s);
+    Mat recoveredROI = blend(roi_d);
 
     Cloning obj;
-    obj.normalClone(dest,cd_mask,dst_mask,blend,flags);
+    obj.normalClone(destinationROI,sourceROI,maskROI,recoveredROI,flags);
 
 }