Image Warping ============= .. highlight:: cpp gpu::remap -------------- Applies a generic geometrical transformation to an image. .. ocv:function:: void gpu::remap( const GpuMat& src, GpuMat& dst, const GpuMat& xmap, const GpuMat& ymap, int interpolation, int borderMode=BORDER_CONSTANT, Scalar borderValue=Scalar(), Stream& stream=Stream::Null() ) :param src: Source image. :param dst: Destination image with the size the same as ``xmap`` and the type the same as ``src`` . :param xmap: X values. Only ``CV_32FC1`` type is supported. :param ymap: Y values. Only ``CV_32FC1`` type is supported. :param interpolation: Interpolation method (see :ocv:func:`resize` ). ``INTER_NEAREST`` , ``INTER_LINEAR`` and ``INTER_CUBIC`` are supported for now. :param borderMode: Pixel extrapolation method (see :ocv:func:`borderInterpolate` ). ``BORDER_REFLECT101`` , ``BORDER_REPLICATE`` , ``BORDER_CONSTANT`` , ``BORDER_REFLECT`` and ``BORDER_WRAP`` are supported for now. :param borderValue: Value used in case of a constant border. By default, it is 0. :param stream: Stream for the asynchronous version. The function transforms the source image using the specified map: .. math:: \texttt{dst} (x,y) = \texttt{src} (xmap(x,y), ymap(x,y)) Values of pixels with non-integer coordinates are computed using the bilinear interpolation. .. seealso:: :ocv:func:`remap` gpu::resize --------------- Resizes an image. .. ocv:function:: void gpu::resize(const GpuMat& src, GpuMat& dst, Size dsize, double fx=0, double fy=0, int interpolation = INTER_LINEAR, Stream& stream = Stream::Null()) :param src: Source image. :param dst: Destination image with the same type as ``src`` . The size is ``dsize`` (when it is non-zero) or the size is computed from ``src.size()`` , ``fx`` , and ``fy`` . :param dsize: Destination image size. If it is zero, it is computed as: .. math:: \texttt{dsize = Size(round(fx*src.cols), round(fy*src.rows))} Either ``dsize`` or both ``fx`` and ``fy`` must be non-zero. :param fx: Scale factor along the horizontal axis. If it is zero, it is computed as: .. math:: \texttt{(double)dsize.width/src.cols} :param fy: Scale factor along the vertical axis. If it is zero, it is computed as: .. math:: \texttt{(double)dsize.height/src.rows} :param interpolation: Interpolation method. ``INTER_NEAREST`` , ``INTER_LINEAR`` and ``INTER_CUBIC`` are supported for now. :param stream: Stream for the asynchronous version. .. seealso:: :ocv:func:`resize` gpu::warpAffine ------------------- Applies an affine transformation to an image. .. ocv:function:: void gpu::warpAffine( const GpuMat& src, GpuMat& dst, const Mat& M, Size dsize, int flags=INTER_LINEAR, int borderMode=BORDER_CONSTANT, Scalar borderValue=Scalar(), Stream& stream=Stream::Null() ) :param src: Source image. ``CV_8U`` , ``CV_16U`` , ``CV_32S`` , or ``CV_32F`` depth and 1, 3, or 4 channels are supported. :param dst: Destination image with the same type as ``src`` . The size is ``dsize`` . :param M: *2x3* transformation matrix. :param dsize: Size of the destination image. :param flags: Combination of interpolation methods (see :ocv:func:`resize`) and the optional flag ``WARP_INVERSE_MAP`` specifying that ``M`` is an inverse transformation ( ``dst=>src`` ). Only ``INTER_NEAREST`` , ``INTER_LINEAR`` , and ``INTER_CUBIC`` interpolation methods are supported. :param stream: Stream for the asynchronous version. .. seealso:: :ocv:func:`warpAffine` gpu::buildWarpAffineMaps ------------------------ Builds transformation maps for affine transformation. .. ocv:function:: void gpu::buildWarpAffineMaps(const Mat& M, bool inverse, Size dsize, GpuMat& xmap, GpuMat& ymap, Stream& stream = Stream::Null()) :param M: *2x3* transformation matrix. :param inverse: Flag specifying that ``M`` is an inverse transformation ( ``dst=>src`` ). :param dsize: Size of the destination image. :param xmap: X values with ``CV_32FC1`` type. :param ymap: Y values with ``CV_32FC1`` type. :param stream: Stream for the asynchronous version. .. seealso:: :ocv:func:`gpu::warpAffine` , :ocv:func:`gpu::remap` gpu::warpPerspective ------------------------ Applies a perspective transformation to an image. .. ocv:function:: void gpu::warpPerspective( const GpuMat& src, GpuMat& dst, const Mat& M, Size dsize, int flags=INTER_LINEAR, int borderMode=BORDER_CONSTANT, Scalar borderValue=Scalar(), Stream& stream=Stream::Null() ) :param src: Source image. ``CV_8U`` , ``CV_16U`` , ``CV_32S`` , or ``CV_32F`` depth and 1, 3, or 4 channels are supported. :param dst: Destination image with the same type as ``src`` . The size is ``dsize`` . :param M: *3x3* transformation matrix. :param dsize: Size of the destination image. :param flags: Combination of interpolation methods (see :ocv:func:`resize` ) and the optional flag ``WARP_INVERSE_MAP`` specifying that ``M`` is the inverse transformation ( ``dst => src`` ). Only ``INTER_NEAREST`` , ``INTER_LINEAR`` , and ``INTER_CUBIC`` interpolation methods are supported. :param stream: Stream for the asynchronous version. .. seealso:: :ocv:func:`warpPerspective` gpu::buildWarpPerspectiveMaps ----------------------------- Builds transformation maps for perspective transformation. .. ocv:function:: void gpu::buildWarpAffineMaps(const Mat& M, bool inverse, Size dsize, GpuMat& xmap, GpuMat& ymap, Stream& stream = Stream::Null()) :param M: *3x3* transformation matrix. :param inverse: Flag specifying that ``M`` is an inverse transformation ( ``dst=>src`` ). :param dsize: Size of the destination image. :param xmap: X values with ``CV_32FC1`` type. :param ymap: Y values with ``CV_32FC1`` type. :param stream: Stream for the asynchronous version. .. seealso:: :ocv:func:`gpu::warpPerspective` , :ocv:func:`gpu::remap` gpu::rotate --------------- Rotates an image around the origin (0,0) and then shifts it. .. ocv:function:: void gpu::rotate(const GpuMat& src, GpuMat& dst, Size dsize, double angle, double xShift = 0, double yShift = 0, int interpolation = INTER_LINEAR, Stream& stream = Stream::Null()) :param src: Source image. Supports 1, 3 or 4 channels images with ``CV_8U`` , ``CV_16U`` or ``CV_32F`` depth. :param dst: Destination image with the same type as ``src`` . The size is ``dsize`` . :param dsize: Size of the destination image. :param angle: Angle of rotation in degrees. :param xShift: Shift along the horizontal axis. :param yShift: Shift along the vertical axis. :param interpolation: Interpolation method. Only ``INTER_NEAREST`` , ``INTER_LINEAR`` , and ``INTER_CUBIC`` are supported. :param stream: Stream for the asynchronous version. .. seealso:: :ocv:func:`gpu::warpAffine` gpu::buildWarpPlaneMaps ----------------------- Builds plane warping maps. .. ocv:function:: void gpu::buildWarpPlaneMaps( Size src_size, Rect dst_roi, const Mat & K, const Mat& R, const Mat & T, float scale, GpuMat& map_x, GpuMat& map_y, Stream& stream=Stream::Null() ) :param stream: Stream for the asynchronous version. gpu::buildWarpCylindricalMaps ----------------------------- Builds cylindrical warping maps. .. ocv:function:: void gpu::buildWarpCylindricalMaps( Size src_size, Rect dst_roi, const Mat & K, const Mat& R, float scale, GpuMat& map_x, GpuMat& map_y, Stream& stream=Stream::Null() ) :param stream: Stream for the asynchronous version. gpu::buildWarpSphericalMaps --------------------------- Builds spherical warping maps. .. ocv:function:: void gpu::buildWarpSphericalMaps( Size src_size, Rect dst_roi, const Mat & K, const Mat& R, float scale, GpuMat& map_x, GpuMat& map_y, Stream& stream=Stream::Null() ) :param stream: Stream for the asynchronous version. gpu::pyrDown ------------------- Smoothes an image and downsamples it. .. ocv:function:: void gpu::pyrDown(const GpuMat& src, GpuMat& dst, Stream& stream = Stream::Null()) :param src: Source image. :param dst: Destination image. Will have ``Size((src.cols+1)/2, (src.rows+1)/2)`` size and the same type as ``src`` . :param stream: Stream for the asynchronous version. .. seealso:: :ocv:func:`pyrDown` gpu::pyrUp ------------------- Upsamples an image and then smoothes it. .. ocv:function:: void gpu::pyrUp(const GpuMat& src, GpuMat& dst, Stream& stream = Stream::Null()) :param src: Source image. :param dst: Destination image. Will have ``Size(src.cols*2, src.rows*2)`` size and the same type as ``src`` . :param stream: Stream for the asynchronous version. .. seealso:: :ocv:func:`pyrUp`