HoughPoint2Line: fixed unsuccessful build

modules/ximgproc/include/opencv2/ximgproc/fast_hough_transform.hpp

@@ -141,10 +141,10 @@ CV_EXPORTS_W void FastHoughTransform( InputArray  src,
 * @brief   Calculates coordinates of line segment corresponded by point in Hough space.
 * @param   houghPoint  Point in Hough space.
 * @param   srcImgInfo The source (input) image of Hough transform.
-* @param   line       Coordinates of line segment corresponded by point in Hough space.
 * @param   angleRange  The part of Hough space where point is situated, see cv::AngleRangeOption
 * @param   makeSkew    Specifies to do or not to do image skewing, see cv::HoughDeskewOption
 * @param   rules       Specifies strictness of line segment calculating, see cv::RulesOption
+* @retval  [Vec4i]     Coordinates of line segment corresponded by point in Hough space.
 * @remarks If rules parameter set to RO_STRICT
            then returned line cut along the border of source image.
 * @remarks If rules parameter set to RO_WEAK then in case of point, which belongs
@@ -152,9 +152,8 @@ CV_EXPORTS_W void FastHoughTransform( InputArray  src,
 *
 * The function calculates coordinates of line segment corresponded by point in Hough space.
 */
-CV_EXPORTS_W void HoughPoint2Line( const Point &houghPoint,
+CV_EXPORTS_W Vec4i HoughPoint2Line(const Point &houghPoint,
                                    InputArray  srcImgInfo,
-                                   Vec4i       &line,
                                    int         angleRange = ARO_315_135,
                                    int         makeSkew = HDO_DESKEW,
                                    int         rules = RO_IGNORE_BORDERS );

modules/ximgproc/samples/fast_hough_transform.cpp

@@ -194,9 +194,7 @@ bool getLocalExtr(vector<Vec4i> &lines,
 
     for (size_t i = 0; i < weightedPoints.size(); ++i)
     {
-        Vec4i houghLine(0, 0, 0, 0);
-        HoughPoint2Line(weightedPoints[i].second, src, houghLine);
-        lines.push_back(houghLine);
+        lines.push_back(HoughPoint2Line(weightedPoints[i].second, src));
     }
     return true;
 }

modules/ximgproc/src/fast_hough_transform.cpp

@@ -835,12 +835,11 @@ static void crossSegments(Point             &point,
     point.y =  cvRound(line1.u.y + mul * (line1.v.y - line1.u.y));
 }
 
-void HoughPoint2Line(const Point &houghPoint,
-                     InputArray  srcImgInfo,
-                     Vec4i       &line,
-                     int         angleRange,
-                     int         makeSkew,
-                     int         rules)
+Vec4i HoughPoint2Line(const Point &houghPoint,
+                      InputArray  srcImgInfo,
+                      int         angleRange,
+                      int         makeSkew,
+                      int         rules)
 {
     Mat srcImgInfoMat = srcImgInfo.getMat();
 
@@ -907,8 +906,7 @@ void HoughPoint2Line(const Point &houghPoint,
 
     if (!ret)
     {
-        line = Vec4i(dstLine.v.x, dstLine.v.y, dstLine.u.x, dstLine.u.y);
-        return;
+        return Vec4i(dstLine.v.x, dstLine.v.y, dstLine.u.x, dstLine.u.y);
     }
 
     if (rules & RO_IGNORE_BORDERS)
@@ -933,8 +931,7 @@ void HoughPoint2Line(const Point &houghPoint,
             break;
         }
 
-        line = Vec4i(dstLine.v.x, dstLine.v.y, dstLine.u.x, dstLine.u.y);
-        return;
+        return Vec4i(dstLine.v.x, dstLine.v.y, dstLine.u.x, dstLine.u.y);
     }
 
     Point minIntersectPoint(0, 0);
@@ -1020,7 +1017,7 @@ void HoughPoint2Line(const Point &houghPoint,
         break;
     }
 
-    line = Vec4i(dstLine.v.x, dstLine.v.y, dstLine.u.x, dstLine.u.y);
+    return Vec4i(dstLine.v.x, dstLine.v.y, dstLine.u.x, dstLine.u.y);
 }
 
 //-----------------------------------------------------------------------------

modules/ximgproc/test/test_fast_hough_transform.cpp

@@ -286,9 +286,8 @@ int TestFHT::validate_line(Mat const& fht,
     {
         Point fht_max(-1, -1);
         minMaxLoc(fht_channels[ch], 0, 0, 0, &fht_max);
-        Vec4i src_line;
-        HoughPoint2Line(fht_max, src, src_line,
-                        ARO_315_135, HDO_DESKEW, RO_STRICT);
+        Vec4i src_line =  HoughPoint2Line(fht_max, src,
+                                          ARO_315_135, HDO_DESKEW, RO_STRICT);
 
         double const a = src_line[1] - src_line[3];
         double const b = src_line[2] - src_line[0];