From d5539975d799962a434c3240b3a752aa6e05187d Mon Sep 17 00:00:00 2001
From: Vadim Pisarevsky <vadim.pisarevsky@gmail.com>
Date: Wed, 7 Aug 2013 22:34:29 +0400
Subject: [PATCH] polished the patch

---
 modules/core/src/dxt.cpp | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/modules/core/src/dxt.cpp b/modules/core/src/dxt.cpp
index 9766752ae7..c76705f1b3 100644
--- a/modules/core/src/dxt.cpp
+++ b/modules/core/src/dxt.cpp
@@ -1547,7 +1547,11 @@ void cv::dft( InputArray _src0, OutputArray _dst, int flags, int nonzero_rows )
 
         spec = 0;
 #ifdef HAVE_IPP
-        if( depth == CV_32F && len*count >= 64 ) // use IPP DFT if available
+        if(
+#if IPP_VERSION_MAJOR >= 7
+           depth == CV_32F && // IPP 7.x and 8.0 have bug somewhere in double-precision DFT
+#endif
+           len*count >= 64 ) // use IPP DFT if available
         {
             int specsize=0, initsize=0, worksize=0;
             IppDFTGetSizeFunc getSizeFunc = 0;
@@ -1556,20 +1560,28 @@ void cv::dft( InputArray _src0, OutputArray _dst, int flags, int nonzero_rows )
             if( real_transform && stage == 0 )
             {
                 if( depth == CV_32F )
-                    getSizeFunc = (IppDFTGetSizeFunc)ippsDFTGetSize_R_32f,
+                {
+                    getSizeFunc = ippsDFTGetSize_R_32f;
                     initFunc = (IppDFTInitFunc)ippsDFTInit_R_32f;
+                }
                 else
-                    getSizeFunc = (IppDFTGetSizeFunc)ippsDFTGetSize_R_64f,
+                {
+                    getSizeFunc = ippsDFTGetSize_R_64f;
                     initFunc = (IppDFTInitFunc)ippsDFTInit_R_64f;
+                }
             }
             else
             {
                 if( depth == CV_32F )
-                    getSizeFunc = (IppDFTGetSizeFunc)ippsDFTGetSize_C_32fc,
+                {
+                    getSizeFunc = ippsDFTGetSize_C_32fc;
                     initFunc = (IppDFTInitFunc)ippsDFTInit_C_32fc;
+                }
                 else
-                    getSizeFunc = (IppDFTGetSizeFunc)ippsDFTGetSize_C_64fc,
+                {
+                    getSizeFunc = ippsDFTGetSize_C_64fc;
                     initFunc = (IppDFTInitFunc)ippsDFTInit_C_64fc;
+                }
             }
             if( getSizeFunc(len, ipp_norm_flag, ippAlgHintNone, &specsize, &initsize, &worksize) >= 0 )
             {
-- 
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