Merge pull request #4149 from LaurentBerger:ThreshGaussianFloat

modules/imgproc/src/thresh.cpp

@@ -1301,11 +1301,17 @@ void cv::adaptiveThreshold( InputArray _src, OutputArray _dst, double maxValue,
     if( src.data != dst.data )
         mean = dst;
 
-    if( method == ADAPTIVE_THRESH_MEAN_C )
+    if (method == ADAPTIVE_THRESH_MEAN_C)
         boxFilter( src, mean, src.type(), Size(blockSize, blockSize),
                    Point(-1,-1), true, BORDER_REPLICATE );
-    else if( method == ADAPTIVE_THRESH_GAUSSIAN_C )
-        GaussianBlur( src, mean, Size(blockSize, blockSize), 0, 0, BORDER_REPLICATE );
+    else if (method == ADAPTIVE_THRESH_GAUSSIAN_C)
+    {
+        Mat srcfloat,meanfloat;
+        src.convertTo(srcfloat,CV_32F);
+        meanfloat=srcfloat;
+        GaussianBlur(srcfloat, meanfloat, Size(blockSize, blockSize), 0, 0, BORDER_REPLICATE);
+        meanfloat.convertTo(dst, src.type());
+    }
     else
         CV_Error( CV_StsBadFlag, "Unknown/unsupported adaptive threshold method" );