Images Warping — OpenCV 2.4.10.0 documentation

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# Images Warping

## detail::RotationWarper

class `detail::``RotationWarper`

Rotation-only model image warper interface.

    class CV_EXPORTS RotationWarper
    {
    public:
        virtual ~RotationWarper() {}

        virtual Point2f warpPoint(const Point2f &pt, const Mat &K, const Mat &R) = 0;

        virtual Rect buildMaps(Size src_size, const Mat &K, const Mat &R, Mat &xmap, Mat &ymap) = 0;

        virtual Point warp(const Mat &src, const Mat &K, const Mat &R, int interp_mode, int border_mode,
                           Mat &dst) = 0;

        virtual void warpBackward(const Mat &src, const Mat &K, const Mat &R, int interp_mode, int border_mode,
                                  Size dst_size, Mat &dst) = 0;

        virtual Rect warpRoi(Size src_size, const Mat &K, const Mat &R) = 0;
    };

## detail::RotationWarper::warpPoint

Projects the image point.

C++:`` Point2f `detail::RotationWarper::``warpPoint`(const Point2f& pt, const Mat& K, const Mat& R)

  Parameters: | pt – Source point K – Camera intrinsic parameters R – Camera rotation matrix
  Returns: | Projected point

## detail::RotationWarper::buildMaps

Builds the projection maps according to the given camera data.

C++:`` Rect `detail::RotationWarper::``buildMaps`(Size src_size, const Mat& K, const Mat& R, Mat& xmap, Mat& ymap)

  Parameters: | src_size – Source image size K – Camera intrinsic parameters R – Camera rotation matrix xmap – Projection map for the x axis ymap – Projection map for the y axis
  Returns: | Projected image minimum bounding box

## detail::RotationWarper::warp

Projects the image.

C++:`` Point `detail::RotationWarper::``warp`(const Mat& src, const Mat& K, const Mat& R, int interp_mode, int border_mode, Mat& dst)

  Parameters: | src – Source image K – Camera intrinsic parameters R – Camera rotation matrix interp_mode – Interpolation mode border_mode – Border extrapolation mode dst – Projected image
  Returns: | Project image top-left corner

## detail::RotationWarper::warpBackward

Projects the image backward.

C++:`` void `detail::RotationWarper::``warpBackward`(const Mat& src, const Mat& K, const Mat& R, int interp_mode, int border_mode, Size dst_size, Mat& dst)

  Parameters: | src – Projected image K – Camera intrinsic parameters R – Camera rotation matrix interp_mode – Interpolation mode border_mode – Border extrapolation mode dst_size – Backward-projected image size dst – Backward-projected image

## detail::RotationWarper::warpRoi

C++:`` Rect `detail::RotationWarper::``warpRoi`(Size src_size, const Mat& K, const Mat& R)

  Parameters: | src_size – Source image bounding box K – Camera intrinsic parameters R – Camera rotation matrix
  Returns: | Projected image minimum bounding box

## detail::ProjectorBase

struct `detail::``ProjectorBase`

Base class for warping logic implementation.

    struct CV_EXPORTS ProjectorBase
    {
        void setCameraParams(const Mat &K = Mat::eye(3, 3, CV_32F),
                            const Mat &R = Mat::eye(3, 3, CV_32F),
                            const Mat &T = Mat::zeros(3, 1, CV_32F));

        float scale;
        float k[9];
        float rinv[9];
        float r_kinv[9];
        float k_rinv[9];
        float t[3];
    };

## detail::RotationWarperBase

class `detail::``RotationWarperBase`

Base class for rotation-based warper using a detail::ProjectorBase derived class.

    template <class P>
    class CV_EXPORTS RotationWarperBase : public RotationWarper
    {
    public:
        Point2f warpPoint(const Point2f &pt, const Mat &K, const Mat &R);

        Rect buildMaps(Size src_size, const Mat &K, const Mat &R, Mat &xmap, Mat &ymap);

        Point warp(const Mat &src, const Mat &K, const Mat &R, int interp_mode, int border_mode,
                Mat &dst);

        void warpBackward(const Mat &src, const Mat &K, const Mat &R, int interp_mode, int border_mode,
                        Size dst_size, Mat &dst);

        Rect warpRoi(Size src_size, const Mat &K, const Mat &R);

    protected:

        // Detects ROI of the destination image. It's correct for any projection.
        virtual void detectResultRoi(Size src_size, Point &dst_tl, Point &dst_br);

        // Detects ROI of the destination image by walking over image border.
        // Correctness for any projection isn't guaranteed.
        void detectResultRoiByBorder(Size src_size, Point &dst_tl, Point &dst_br);

        P projector_;
    };

## detail::PlaneWarper

class `detail::``PlaneWarper` : public `detail::``RotationWarperBase<PlaneProjector>`

Warper that maps an image onto the z = 1 plane.

    class CV_EXPORTS PlaneWarper : public RotationWarperBase<PlaneProjector>
    {
    public:
        PlaneWarper(float scale = 1.f) { projector_.scale = scale; }

        void setScale(float scale) { projector_.scale = scale; }

        Point2f warpPoint(const Point2f &pt, const Mat &K, const Mat &R, const Mat &T);

        Rect buildMaps(Size src_size, const Mat &K, const Mat &R, const Mat &T, Mat &xmap, Mat &ymap);

        Point warp(const Mat &src, const Mat &K, const Mat &R, const Mat &T, int interp_mode, int border_mode,
                   Mat &dst);

        Rect warpRoi(Size src_size, const Mat &K, const Mat &R, const Mat &T);

    protected:
        void detectResultRoi(Size src_size, Point &dst_tl, Point &dst_br);
    };

See also

`detail::RotationWarper`

## detail::PlaneWarper::PlaneWarper

Construct an instance of the plane warper class.

C++:`` void `detail::PlaneWarper::``PlaneWarper`(float scale=1.f)

  Parameters: | scale – Projected image scale multiplier

## detail::SphericalWarper

class `detail::``SphericalWarper` : public `detail::``RotationWarperBase<SphericalProjector>`

Warper that maps an image onto the unit sphere located at the origin.

    class CV_EXPORTS SphericalWarper : public RotationWarperBase<SphericalProjector>
    {
    public:
        SphericalWarper(float scale) { projector_.scale = scale; }

    protected:
        void detectResultRoi(Size src_size, Point &dst_tl, Point &dst_br);
    };

See also

`detail::RotationWarper`

## detail::SphericalWarper::SphericalWarper

Construct an instance of the spherical warper class.

C++:`` void `detail::SphericalWarper::``SphericalWarper`(float scale)

  Parameters: | scale – Projected image scale multiplier

## detail::CylindricalWarper

class `detail::``CylindricalWarper` : public `detail::``RotationWarperBase<CylindricalProjector>`

Warper that maps an image onto the x*x + z*z = 1 cylinder.

    class CV_EXPORTS CylindricalWarper : public RotationWarperBase<CylindricalProjector>
    {
    public:
        CylindricalWarper(float scale) { projector_.scale = scale; }

    protected:
        void detectResultRoi(Size src_size, Point &dst_tl, Point &dst_br)
        {
            RotationWarperBase<CylindricalProjector>::detectResultRoiByBorder(src_size, dst_tl, dst_br);
        }
    };

See also

`detail::RotationWarper`

## detail::CylindricalWarper::CylindricalWarper

Construct an instance of the cylindrical warper class.

C++:`` void `detail::CylindricalWarper::``CylindricalWarper`(float scale)

  Parameters: | scale – Projected image scale multiplier

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