@@ -483,88 +483,6 @@ Draws several polygonal curves.
The function ``polylines`` draws one or more polygonal curves.
drawContours
----------------
Draws contours outlines or filled contours.
.. ocv:function:: void drawContours( InputOutputArray image, InputArrayOfArrays contours, int contourIdx, const Scalar& color, int thickness=1, int lineType=8, InputArray hierarchy=noArray(), int maxLevel=INT_MAX, Point offset=Point() )
:param contours: All the input contours. Each contour is stored as a point vector.
:param contourIdx: Parameter indicating a contour to draw. If it is negative, all the contours are drawn.
:param color: Color of the contours.
:param thickness: Thickness of lines the contours are drawn with. If it is negative (for example, ``thickness=CV_FILLED`` ), the contour interiors are
drawn.
:param lineType: Line connectivity. See :ocv:func:`line` for details.
:param hierarchy: Optional information about hierarchy. It is only needed if you want to draw only some of the contours (see ``maxLevel`` ).
:param maxLevel: Maximal level for drawn contours. If it is 0, only
the specified contour is drawn. If it is 1, the function draws the contour(s) and all the nested contours. If it is 2, the function draws the contours, all the nested contours, all the nested-to-nested contours, and so on. This parameter is only taken into account when there is ``hierarchy`` available.
:param offset: Optional contour shift parameter. Shift all the drawn contours by the specified :math:`\texttt{offset}=(dx,dy)` .
:param contour: Pointer to the first contour.
:param external_color: Color of external contours.
:param hole_color: Color of internal contours (holes).
The function draws contour outlines in the image if
:math:`\texttt{thickness} \ge 0` or fills the area bounded by the contours if
:math:`\texttt{thickness}<0` . The example below shows how to retrieve connected components from the binary image and label them: ::
#include "cv.h"
#include "highgui.h"
using namespace cv;
int main( int argc, char** argv )
{
Mat src;
// the first command-line parameter must be a filename of the binary
// (black-n-white) image
if( argc != 2 || !(src=imread(argv[1], 0)).data)
return -1;
Mat dst = Mat::zeros(src.rows, src.cols, CV_8UC3);
src = src > 1;
namedWindow( "Source", 1 );
imshow( "Source", src );
vector<vector<Point> > contours;
vector<Vec4i> hierarchy;
findContours( src, contours, hierarchy,
CV_RETR_CCOMP, CV_CHAIN_APPROX_SIMPLE );
// iterate through all the top-level contours,
// draw each connected component with its own random color
@@ -166,6 +166,87 @@ The function retrieves contours from the binary image using the algorithm
.. note:: If you use the new Python interface then the ``CV_`` prefix has to be omitted in contour retrieval mode and contour approximation method parameters (for example, use ``cv2.RETR_LIST`` and ``cv2.CHAIN_APPROX_NONE`` parameters). If you use the old Python interface then these parameters have the ``CV_`` prefix (for example, use ``cv.CV_RETR_LIST`` and ``cv.CV_CHAIN_APPROX_NONE``).
drawContours
----------------
Draws contours outlines or filled contours.
.. ocv:function:: void drawContours( InputOutputArray image, InputArrayOfArrays contours, int contourIdx, const Scalar& color, int thickness=1, int lineType=8, InputArray hierarchy=noArray(), int maxLevel=INT_MAX, Point offset=Point() )
:param contours: All the input contours. Each contour is stored as a point vector.
:param contourIdx: Parameter indicating a contour to draw. If it is negative, all the contours are drawn.
:param color: Color of the contours.
:param thickness: Thickness of lines the contours are drawn with. If it is negative (for example, ``thickness=CV_FILLED`` ), the contour interiors are
drawn.
:param lineType: Line connectivity. See :ocv:func:`line` for details.
:param hierarchy: Optional information about hierarchy. It is only needed if you want to draw only some of the contours (see ``maxLevel`` ).
:param maxLevel: Maximal level for drawn contours. If it is 0, only
the specified contour is drawn. If it is 1, the function draws the contour(s) and all the nested contours. If it is 2, the function draws the contours, all the nested contours, all the nested-to-nested contours, and so on. This parameter is only taken into account when there is ``hierarchy`` available.
:param offset: Optional contour shift parameter. Shift all the drawn contours by the specified :math:`\texttt{offset}=(dx,dy)` .
:param contour: Pointer to the first contour.
:param externalColor: Color of external contours.
:param holeColor: Color of internal contours (holes).
The function draws contour outlines in the image if
:math:`\texttt{thickness} \ge 0` or fills the area bounded by the contours if
:math:`\texttt{thickness}<0` . The example below shows how to retrieve connected components from the binary image and label them: ::
#include "cv.h"
#include "highgui.h"
using namespace cv;
int main( int argc, char** argv )
{
Mat src;
// the first command-line parameter must be a filename of the binary
// (black-n-white) image
if( argc != 2 || !(src=imread(argv[1], 0)).data)
return -1;
Mat dst = Mat::zeros(src.rows, src.cols, CV_8UC3);
src = src > 1;
namedWindow( "Source", 1 );
imshow( "Source", src );
vector<vector<Point> > contours;
vector<Vec4i> hierarchy;
findContours( src, contours, hierarchy,
CV_RETR_CCOMP, CV_CHAIN_APPROX_SIMPLE );
// iterate through all the top-level contours,
// draw each connected component with its own random color
