Merge pull request #8238 from PkLab:fix_doc_ellipse

modules/imgproc/include/opencv2/imgproc.hpp

@@ -4198,13 +4198,14 @@ CV_EXPORTS_W void circle(InputOutputArray img, Point center, int radius,
 /** @brief Draws a simple or thick elliptic arc or fills an ellipse sector.
 
 The function cv::ellipse with less parameters draws an ellipse outline, a filled ellipse, an elliptic
-arc, or a filled ellipse sector. A piecewise-linear curve is used to approximate the elliptic arc
+arc, or a filled ellipse sector. The drawing code uses general parametric form.
+A piecewise-linear curve is used to approximate the elliptic arc
 boundary. If you need more control of the ellipse rendering, you can retrieve the curve using
-ellipse2Poly and then render it with polylines or fill it with fillPoly . If you use the first
-variant of the function and want to draw the whole ellipse, not an arc, pass startAngle=0 and
-endAngle=360 . The figure below explains the meaning of the parameters.
+cv::ellipse2Poly and then render it with polylines or fill it with cv::fillPoly. If you use the first
+variant of the function and want to draw the whole ellipse, not an arc, pass `startAngle=0` and
+`endAngle=360`. The figure below explains the meaning of the parameters to draw the blue arc.
 
-![Parameters of Elliptic Arc](pics/ellipse.png)
+![Parameters of Elliptic Arc](pics/ellipse.svg)
 
 @param img Image.
 @param center Center of the ellipse.