Move OpenVX integrations to imgproc to OpenVX HAL

Covered functions:
- medianBlur
- Sobel
- Canny
- pyrDown
- BoxFilter
- equalizeHist
- GaussianBlur
- remap
- threshold

modules/imgproc/src/histogram.cpp

@@ -3396,43 +3396,6 @@ static bool ocl_equalizeHist(InputArray _src, OutputArray _dst)
 
 #endif
 
-#ifdef HAVE_OPENVX
-namespace cv
-{
-static bool openvx_equalize_hist(Mat srcMat, Mat dstMat)
-{
-    using namespace ivx;
-
-    try
-    {
-        Context context = ovx::getOpenVXContext();
-        Image srcImage = Image::createFromHandle(context, Image::matTypeToFormat(srcMat.type()),
-                                                 Image::createAddressing(srcMat), srcMat.data);
-        Image dstImage = Image::createFromHandle(context, Image::matTypeToFormat(dstMat.type()),
-                                                 Image::createAddressing(dstMat), dstMat.data);
-
-        IVX_CHECK_STATUS(vxuEqualizeHist(context, srcImage, dstImage));
-
-#ifdef VX_VERSION_1_1
-        //we should take user memory back before release
-        //(it's not done automatically according to standard)
-        srcImage.swapHandle(); dstImage.swapHandle();
-#endif
-    }
-    catch (const RuntimeError & e)
-    {
-        VX_DbgThrow(e.what());
-    }
-    catch (const WrapperError & e)
-    {
-        VX_DbgThrow(e.what());
-    }
-
-    return true;
-}
-}
-#endif
-
 void cv::equalizeHist( InputArray _src, OutputArray _dst )
 {
     CV_INSTRUMENT_REGION();
@@ -3449,9 +3412,6 @@ void cv::equalizeHist( InputArray _src, OutputArray _dst )
     _dst.create( src.size(), src.type() );
     Mat dst = _dst.getMat();
 
-    CV_OVX_RUN(!ovx::skipSmallImages<VX_KERNEL_EQUALIZE_HISTOGRAM>(src.cols, src.rows),
-               openvx_equalize_hist(src, dst))
-
     CALL_HAL(equalizeHist, cv_hal_equalize_hist, src.data, src.step, dst.data, dst.step, src.cols, src.rows);
 
     Mutex histogramLockInstance;