Merge pull request #5386 from StevenPuttemans:add_markers

modules/imgproc/include/opencv2/imgproc.hpp

@@ -3904,6 +3904,43 @@ a filled ellipse sector is to be drawn.
 CV_EXPORTS_W void ellipse(InputOutputArray img, const RotatedRect& box, const Scalar& color,
                         int thickness = 1, int lineType = LINE_8);
 
+/* ----------------------------------------------------------------------------------------- */
+/* ADDING A SET OF PREDEFINED MARKERS WHICH COULD BE USED TO HIGHLIGHT POSITIONS IN AN IMAGE */
+/* ----------------------------------------------------------------------------------------- */
+
+//! Possible set of marker types used for the cv::drawMarker function
+enum MarkerTypes
+{
+    MARKER_CROSS = 0,           //!< A crosshair marker shape
+    MARKER_TILTED_CROSS = 1,    //!< A 45 degree tilted crosshair marker shape
+    MARKER_STAR = 2,            //!< A star marker shape, combination of cross and tilted cross
+    MARKER_DIAMOND = 3,         //!< A diamond marker shape
+    MARKER_SQUARE = 4,          //!< A square marker shape
+    MARKER_TRIANGLE_UP = 5,     //!< An upwards pointing triangle marker shape
+    MARKER_TRIANGLE_DOWN = 6    //!< A downwards pointing triangle marker shape
+};
+
+/** @brief Draws a marker on a predefined position in an image.
+
+The function drawMarker draws a marker on a given position in the image. For the moment several
+marker types are supported, see cv::MarkerTypes for more information.
+
+@param img Image.
+@param position The point where the crosshair is positioned.
+@param markerType The specific type of marker you want to use, see cv::MarkerTypes
+@param color Line color.
+@param thickness Line thickness.
+@param line_type Type of the line, see cv::LineTypes
+@param markerSize The length of the marker axis [default = 20 pixels]
+ */
+CV_EXPORTS_W void drawMarker(CV_IN_OUT Mat& img, Point position, const Scalar& color,
+                             int markerType = MARKER_CROSS, int markerSize=20, int thickness=1,
+                             int line_type=8);
+
+/* ----------------------------------------------------------------------------------------- */
+/* END OF MARKER SECTION */
+/* ----------------------------------------------------------------------------------------- */
+
 /** @overload */
 CV_EXPORTS void fillConvexPoly(Mat& img, const Point* pts, int npts,
                                const Scalar& color, int lineType = LINE_8,

modules/imgproc/src/drawing.cpp

@@ -1654,6 +1654,71 @@ PolyLine( Mat& img, const Point* v, int count, bool is_closed,
     }
 }
 
+/* ----------------------------------------------------------------------------------------- */
+/* ADDING A SET OF PREDEFINED MARKERS WHICH COULD BE USED TO HIGHLIGHT POSITIONS IN AN IMAGE */
+/* ----------------------------------------------------------------------------------------- */
+
+void drawMarker(Mat& img, Point position, const Scalar& color, int markerType, int markerSize, int thickness, int line_type)
+{
+    switch(markerType)
+    {
+    // The cross marker case
+    case MARKER_CROSS:
+        line(img, Point(position.x-(markerSize/2), position.y), Point(position.x+(markerSize/2), position.y), color, thickness, line_type);
+        line(img, Point(position.x, position.y-(markerSize/2)), Point(position.x, position.y+(markerSize/2)), color, thickness, line_type);
+        break;
+
+    // The tilted cross marker case
+    case MARKER_TILTED_CROSS:
+        line(img, Point(position.x-(markerSize/2), position.y-(markerSize/2)), Point(position.x+(markerSize/2), position.y+(markerSize/2)), color, thickness, line_type);
+        line(img, Point(position.x+(markerSize/2), position.y-(markerSize/2)), Point(position.x-(markerSize/2), position.y+(markerSize/2)), color, thickness, line_type);
+        break;
+
+    // The star marker case
+    case MARKER_STAR:
+        line(img, Point(position.x-(markerSize/2), position.y), Point(position.x+(markerSize/2), position.y), color, thickness, line_type);
+        line(img, Point(position.x, position.y-(markerSize/2)), Point(position.x, position.y+(markerSize/2)), color, thickness, line_type);
+        line(img, Point(position.x-(markerSize/2), position.y-(markerSize/2)), Point(position.x+(markerSize/2), position.y+(markerSize/2)), color, thickness, line_type);
+        line(img, Point(position.x+(markerSize/2), position.y-(markerSize/2)), Point(position.x-(markerSize/2), position.y+(markerSize/2)), color, thickness, line_type);
+        break;
+
+    // The diamond marker case
+    case MARKER_DIAMOND:
+        line(img, Point(position.x, position.y-(markerSize/2)), Point(position.x+(markerSize/2), position.y), color, thickness, line_type);
+        line(img, Point(position.x+(markerSize/2), position.y), Point(position.x, position.y+(markerSize/2)), color, thickness, line_type);
+        line(img, Point(position.x, position.y+(markerSize/2)), Point(position.x-(markerSize/2), position.y), color, thickness, line_type);
+        line(img, Point(position.x-(markerSize/2), position.y), Point(position.x, position.y-(markerSize/2)), color, thickness, line_type);
+        break;
+
+    // The square marker case
+    case MARKER_SQUARE:
+        line(img, Point(position.x-(markerSize/2), position.y-(markerSize/2)), Point(position.x+(markerSize/2), position.y-(markerSize/2)), color, thickness, line_type);
+        line(img, Point(position.x+(markerSize/2), position.y-(markerSize/2)), Point(position.x+(markerSize/2), position.y+(markerSize/2)), color, thickness, line_type);
+        line(img, Point(position.x+(markerSize/2), position.y+(markerSize/2)), Point(position.x-(markerSize/2), position.y+(markerSize/2)), color, thickness, line_type);
+        line(img, Point(position.x-(markerSize/2), position.y+(markerSize/2)), Point(position.x-(markerSize/2), position.y-(markerSize/2)), color, thickness, line_type);
+        break;
+
+    // The triangle up marker case
+    case MARKER_TRIANGLE_UP:
+        line(img, Point(position.x-(markerSize/2), position.y+(markerSize/2)), Point(position.x+(markerSize/2), position.y+(markerSize/2)), color, thickness, line_type);
+        line(img, Point(position.x+(markerSize/2), position.y+(markerSize/2)), Point(position.x, position.y-(markerSize/2)), color, thickness, line_type);
+        line(img, Point(position.x, position.y-(markerSize/2)), Point(position.x-(markerSize/2), position.y-(markerSize/2)), color, thickness, line_type);
+        break;
+
+    // The triangle down marker case
+    case MARKER_TRIANGLE_DOWN:
+        line(img, Point(position.x-(markerSize/2), position.y-(markerSize/2)), Point(position.x+(markerSize/2), position.y-(markerSize/2)), color, thickness, line_type);
+        line(img, Point(position.x+(markerSize/2), position.y-(markerSize/2)), Point(position.x, position.y+(markerSize/2)), color, thickness, line_type);
+        line(img, Point(position.x, position.y+(markerSize/2)), Point(position.x-(markerSize/2), position.y-(markerSize/2)), color, thickness, line_type);
+        break;
+
+    // If any number that doesn't exist is entered as marker type, draw a cross marker, to avoid crashes
+    default:
+        drawMarker(img, position, color, MARKER_CROSS, markerSize, thickness, line_type);
+        break;
+    }
+}
+
 /****************************************************************************************\
 *                              External functions                                        *
 \****************************************************************************************/