imgproc(getPerspectiveTransform): add solveMethod parameter

drop compatibility workaround via runtime parameter

modules/imgproc/include/opencv2/imgproc.hpp

@@ -2359,9 +2359,6 @@ coordinate origin is assumed to be the top-left corner).
  */
 CV_EXPORTS_W Mat getRotationMatrix2D( Point2f center, double angle, double scale );
 
-//! returns 3x3 perspective transformation for the corresponding 4 point pairs.
-CV_EXPORTS Mat getPerspectiveTransform( const Point2f src[], const Point2f dst[] );
-
 /** @brief Calculates an affine transform from three pairs of the corresponding points.
 
 The function calculates the \f$2 \times 3\f$ matrix of an affine transform so that:
@@ -2404,10 +2401,15 @@ where
 
 @param src Coordinates of quadrangle vertices in the source image.
 @param dst Coordinates of the corresponding quadrangle vertices in the destination image.
+@param solveMethod method passed to cv::solve (#DecompTypes)
 
 @sa  findHomography, warpPerspective, perspectiveTransform
  */
-CV_EXPORTS_W Mat getPerspectiveTransform( InputArray src, InputArray dst );
+CV_EXPORTS_W Mat getPerspectiveTransform(InputArray src, InputArray dst, int solveMethod = DECOMP_LU);
+
+/** @overload */
+CV_EXPORTS Mat getPerspectiveTransform(const Point2f src[], const Point2f dst[], int solveMethod = DECOMP_LU);
+
 
 CV_EXPORTS_W Mat getAffineTransform( InputArray src, InputArray dst );
 

modules/imgproc/perf/perf_warp.cpp

@@ -290,4 +290,23 @@ PERF_TEST(Transform, getPerspectiveTransform_1000)
     SANITY_CHECK_NOTHING();
 }
 
+PERF_TEST(Transform, getPerspectiveTransform_QR_1000)
+{
+    unsigned int size = 8;
+    Mat source(1, size/2, CV_32FC2);
+    Mat destination(1, size/2, CV_32FC2);
+    Mat transformCoefficient;
+
+    declare.in(source, destination, WARMUP_RNG);
+
+    PERF_SAMPLE_BEGIN()
+    for (int i = 0; i < 1000; i++)
+    {
+        transformCoefficient = getPerspectiveTransform(source, destination, DECOMP_QR);
+    }
+    PERF_SAMPLE_END()
+
+    SANITY_CHECK_NOTHING();
+}
+
 } // namespace

modules/imgproc/src/imgwarp.cpp

@@ -3039,7 +3039,7 @@ cv::Mat cv::getRotationMatrix2D( Point2f center, double angle, double scale )
  * where:
  *   cij - matrix coefficients, c22 = 1
  */
-cv::Mat cv::getPerspectiveTransform( const Point2f src[], const Point2f dst[] )
+cv::Mat cv::getPerspectiveTransform(const Point2f src[], const Point2f dst[], int solveMethod)
 {
     CV_INSTRUMENT_REGION()
 
@@ -3062,9 +3062,7 @@ cv::Mat cv::getPerspectiveTransform( const Point2f src[], const Point2f dst[] )
         b[i+4] = dst[i].y;
     }
 
-    static int param_IMGPROC_GETPERSPECTIVETRANSFORM_SOLVE_METHOD =
-        (int)utils::getConfigurationParameterSizeT("OPENCV_IMGPROC_GETPERSPECTIVETRANSFORM_SOLVE_METHOD", (size_t)DECOMP_LU);
-    solve(A, B, X, param_IMGPROC_GETPERSPECTIVETRANSFORM_SOLVE_METHOD);
+    solve(A, B, X, solveMethod);
     M.ptr<double>()[8] = 1.;
 
     return M;
@@ -3153,11 +3151,11 @@ void cv::invertAffineTransform(InputArray _matM, OutputArray __iM)
         CV_Error( CV_StsUnsupportedFormat, "" );
 }
 
-cv::Mat cv::getPerspectiveTransform(InputArray _src, InputArray _dst)
+cv::Mat cv::getPerspectiveTransform(InputArray _src, InputArray _dst, int solveMethod)
 {
     Mat src = _src.getMat(), dst = _dst.getMat();
     CV_Assert(src.checkVector(2, CV_32F) == 4 && dst.checkVector(2, CV_32F) == 4);
-    return getPerspectiveTransform((const Point2f*)src.data, (const Point2f*)dst.data);
+    return getPerspectiveTransform((const Point2f*)src.data, (const Point2f*)dst.data, solveMethod);
 }
 
 cv::Mat cv::getAffineTransform(InputArray _src, InputArray _dst)