Changed the signature of the minEnclosingTriangle function such that …

…it returns the area automatically. Moreover, the overloaded function was no longer required so it was removed. Sample code, documentation and unit tests were updated correspondingly.

modules/imgproc/doc/structural_analysis_and_shape_descriptors.rst

@@ -562,15 +562,11 @@ The function finds the four vertices of a rotated rectangle. This function is us
 
 minEnclosingTriangle
 ----------------------
-Finds a triangle of minimum area enclosing a 2D point set.
+Finds a triangle of minimum area enclosing a 2D point set and returns its area.
 
-.. ocv:function:: void minEnclosingTriangle( InputArray points, OutputArray triangle )
+.. ocv:function:: double minEnclosingTriangle( InputArray points, OutputArray triangle )
 
-.. ocv:function:: void minEnclosingTriangle( InputArray points, OutputArray triangle, double &area )
-
-.. ocv:pyfunction:: cv2.minEnclosingTriangle(points[, triangle]) -> triangle
-
-.. ocv:pyfunction:: cv2.minEnclosingTriangle(points[, triangle]) -> triangle, area
+.. ocv:pyfunction:: cv2.minEnclosingTriangle(points[, triangle]) -> retval, triangle
 
     :param points: Input vector of 2D points with depth ``CV_32S`` or ``CV_32F``, stored in:
 
@@ -580,9 +576,7 @@ Finds a triangle of minimum area enclosing a 2D point set.
 
     :param triangle: Output vector of three 2D points defining the vertices of the triangle. The depth of the OutputArray must be ``CV_32F``.
 
-    :param area: The area of the minimum enclosing triangle.
-
-The output for a given 2D point set is shown in the image below. The 2D points are depicted in *red* and the enclosing triangle in *yellow*.
+The function finds a triangle of minimum area enclosing the given set of 2D points and returns its area. The output for a given 2D point set is shown in the image below. 2D points are depicted in *red* and the enclosing triangle in *yellow*.
 
 .. image:: pics/minenclosingtriangle.png
     :height: 250px

modules/imgproc/include/opencv2/imgproc.hpp

@@ -1451,13 +1451,8 @@ CV_EXPORTS_W void boxPoints(RotatedRect box, OutputArray points);
 CV_EXPORTS_W void minEnclosingCircle( InputArray points,
                                       CV_OUT Point2f& center, CV_OUT float& radius );
 
-//! computes the minimal enclosing triangle for a set of points
-CV_EXPORTS_W void minEnclosingTriangle( InputArray points,
-                                        CV_OUT OutputArray triangle );
-
-//! computes the minimal enclosing triangle for a set of points
-CV_EXPORTS_W void minEnclosingTriangle( InputArray points,
-                                        CV_OUT OutputArray triangle, CV_OUT double& area );
+//! computes the minimal enclosing triangle for a set of points and returns its area
+CV_EXPORTS_W double minEnclosingTriangle( InputArray points, CV_OUT OutputArray triangle );
 
 //! matches two contours using one of the available algorithms
 CV_EXPORTS_W double matchShapes( InputArray contour1, InputArray contour2,

modules/imgproc/src/min_enclosing_triangle.cpp

@@ -269,27 +269,17 @@ static void updateSidesCA();
 ///////////////////////////////////// Main functions /////////////////////////////////////
 
 
-//! Find the minimum enclosing triangle and its area for the given set of points
+//! Find the minimum enclosing triangle for the given set of points and return its area
 /*!
 * @param points         Set of points
 * @param triangle       Minimum area triangle enclosing the given set of points
-* @param area           Area of the minimum area enclosing triangle
 */
-void cv::minEnclosingTriangle(cv::InputArray points,
-                              CV_OUT cv::OutputArray triangle, CV_OUT double &area) {
-    minEnclosingTriangle::findMinEnclosingTriangle(points, triangle, area);
-}
-
-//! Find the minimum enclosing triangle and its area for the given set of points
-/*!
-* @param points         Set of points
-* @param triangle       Minimum area triangle enclosing the given set of points
-*/
-void cv::minEnclosingTriangle(cv::InputArray points,
-                              CV_OUT cv::OutputArray triangle) {
+double cv::minEnclosingTriangle(cv::InputArray points, CV_OUT cv::OutputArray triangle) {
     double area;
 
     minEnclosingTriangle::findMinEnclosingTriangle(points, triangle, area);
+
+    return area;
 }
 
 

modules/imgproc/test/test_convhull.cpp

@@ -801,7 +801,6 @@ class CV_MinTriangleTest : public CV_BaseShapeDescrTest
 
     std::vector<cv::Point2f> convexPolygon;
     std::vector<cv::Point2f> triangle;
-    double area;
 };
 
 
@@ -827,7 +826,7 @@ void CV_MinTriangleTest::run_func()
 
     cv::cvarrToMat(points).convertTo(pointsAsVector, CV_32F);
 
-    cv::minEnclosingTriangle(pointsAsVector, triangle, area);
+    cv::minEnclosingTriangle(pointsAsVector, triangle);
     cv::convexHull(pointsAsVector, convexPolygon, true, true);
 }