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# Drawing Functions for Keylines and Matches

## drawLineMatches

Draws the found matches of keylines from two images.

C++:`` void `drawLineMatches`(const Mat& img1, const std::vector<KeyLine>& keylines1, const Mat& img2, const std::vector<KeyLine>& keylines2, const std::vector<DMatch>& matches1to2, Mat& outImg, const Scalar& matchColor=Scalar::all(-1), const Scalar& singleLineColor=Scalar::all(-1), const std::vector<char>& matchesMask=std::vector<char>(), int flags=DrawLinesMatchesFlags::DEFAULT )

  Parameters: | img1 – first image keylines1 – keylines extracted from first image img2 – second image keylines2 – keylines extracted from second image matches1to2 – vector of matches outImg – output matrix to draw on matchColor – drawing color for matches (chosen randomly in case of default value) singleLineColor – drawing color for keylines (chosen randomly in case of default value) matchesMask – mask to indicate which matches must be drawn flags – drawing flags

Note

If both matchColor and singleLineColor are set to their default values, function draws matched lines and line connecting them with same color

The structure of drawing flags is shown in the following:

    /* struct for drawing options */
    struct CV_EXPORTS DrawLinesMatchesFlags
    {
            enum
            {
                DEFAULT = 0, // Output image matrix will be created (Mat::create),
                             // i.e. existing memory of output image may be reused.
                             // Two source images, matches, and single keylines
                             // will be drawn.
                DRAW_OVER_OUTIMG = 1, // Output image matrix will not be
                               // created (using Mat::create). Matches will be drawn
                               // on existing content of output image.
                NOT_DRAW_SINGLE_LINES = 2 // Single keylines will not be drawn.
            };
    };

## drawKeylines

Draws keylines.

C++:`` void `drawKeylines`(const Mat& image, const std::vector<KeyLine>& keylines, Mat& outImage, const Scalar& color=Scalar::all(-1), int flags=DrawLinesMatchesFlags::DEFAULT )

  Parameters: | image – input image keylines – keylines to be drawn outImage – output image to draw on color – color of lines to be drawn (if set to defaul value, color is chosen randomly) flags – drawing flags

## Related pages

- Binary descriptors for lines extracted from an image
- BinaryDescriptor Class
- Matching with binary descriptors

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### Navigation

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