opencv/modules/gpuimgproc/doc/imgproc.rst

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Image Processing
================
.. highlight:: cpp
gpu::meanShiftFiltering
---------------------------
Performs mean-shift filtering for each point of the source image.
.. ocv:function:: void gpu::meanShiftFiltering( const GpuMat& src, GpuMat& dst, int sp, int sr, TermCriteria criteria=TermCriteria(TermCriteria::MAX_ITER + TermCriteria::EPS, 5, 1), Stream& stream=Stream::Null() )
:param src: Source image. Only ``CV_8UC4`` images are supported for now.
:param dst: Destination image containing the color of mapped points. It has the same size and type as ``src`` .
:param sp: Spatial window radius.
:param sr: Color window radius.
:param criteria: Termination criteria. See :ocv:class:`TermCriteria`.
It maps each point of the source image into another point. As a result, you have a new color and new position of each point.
gpu::meanShiftProc
----------------------
Performs a mean-shift procedure and stores information about processed points (their colors and positions) in two images.
.. ocv:function:: void gpu::meanShiftProc( const GpuMat& src, GpuMat& dstr, GpuMat& dstsp, int sp, int sr, TermCriteria criteria=TermCriteria(TermCriteria::MAX_ITER + TermCriteria::EPS, 5, 1), Stream& stream=Stream::Null() )
:param src: Source image. Only ``CV_8UC4`` images are supported for now.
:param dstr: Destination image containing the color of mapped points. The size and type is the same as ``src`` .
:param dstsp: Destination image containing the position of mapped points. The size is the same as ``src`` size. The type is ``CV_16SC2`` .
:param sp: Spatial window radius.
:param sr: Color window radius.
:param criteria: Termination criteria. See :ocv:class:`TermCriteria`.
.. seealso:: :ocv:func:`gpu::meanShiftFiltering`
gpu::meanShiftSegmentation
------------------------------
Performs a mean-shift segmentation of the source image and eliminates small segments.
.. ocv:function:: void gpu::meanShiftSegmentation(const GpuMat& src, Mat& dst, int sp, int sr, int minsize, TermCriteria criteria = TermCriteria(TermCriteria::MAX_ITER + TermCriteria::EPS, 5, 1))
:param src: Source image. Only ``CV_8UC4`` images are supported for now.
:param dst: Segmented image with the same size and type as ``src`` .
:param sp: Spatial window radius.
:param sr: Color window radius.
:param minsize: Minimum segment size. Smaller segments are merged.
:param criteria: Termination criteria. See :ocv:class:`TermCriteria`.
gpu::MatchTemplateBuf
---------------------
.. ocv:struct:: gpu::MatchTemplateBuf
Class providing memory buffers for :ocv:func:`gpu::matchTemplate` function, plus it allows to adjust some specific parameters. ::
struct CV_EXPORTS MatchTemplateBuf
{
Size user_block_size;
GpuMat imagef, templf;
std::vector<GpuMat> images;
std::vector<GpuMat> image_sums;
std::vector<GpuMat> image_sqsums;
};
You can use field `user_block_size` to set specific block size for :ocv:func:`gpu::matchTemplate` function. If you leave its default value `Size(0,0)` then automatic estimation of block size will be used (which is optimized for speed). By varying `user_block_size` you can reduce memory requirements at the cost of speed.
gpu::matchTemplate
----------------------
Computes a proximity map for a raster template and an image where the template is searched for.
.. ocv:function:: void gpu::matchTemplate(const GpuMat& image, const GpuMat& templ, GpuMat& result, int method, Stream &stream = Stream::Null())
.. ocv:function:: void gpu::matchTemplate(const GpuMat& image, const GpuMat& templ, GpuMat& result, int method, MatchTemplateBuf &buf, Stream& stream = Stream::Null())
:param image: Source image. ``CV_32F`` and ``CV_8U`` depth images (1..4 channels) are supported for now.
:param templ: Template image with the size and type the same as ``image`` .
:param result: Map containing comparison results ( ``CV_32FC1`` ). If ``image`` is *W x H* and ``templ`` is *w x h*, then ``result`` must be *W-w+1 x H-h+1*.
:param method: Specifies the way to compare the template with the image.
:param buf: Optional buffer to avoid extra memory allocations and to adjust some specific parameters. See :ocv:struct:`gpu::MatchTemplateBuf`.
:param stream: Stream for the asynchronous version.
The following methods are supported for the ``CV_8U`` depth images for now:
* ``CV_TM_SQDIFF``
* ``CV_TM_SQDIFF_NORMED``
* ``CV_TM_CCORR``
* ``CV_TM_CCORR_NORMED``
* ``CV_TM_CCOEFF``
* ``CV_TM_CCOEFF_NORMED``
The following methods are supported for the ``CV_32F`` images for now:
* ``CV_TM_SQDIFF``
* ``CV_TM_CCORR``
.. seealso:: :ocv:func:`matchTemplate`
gpu::Canny
-------------------
Finds edges in an image using the [Canny86]_ algorithm.
.. ocv:function:: void gpu::Canny(const GpuMat& image, GpuMat& edges, double low_thresh, double high_thresh, int apperture_size = 3, bool L2gradient = false)
.. ocv:function:: void gpu::Canny(const GpuMat& image, CannyBuf& buf, GpuMat& edges, double low_thresh, double high_thresh, int apperture_size = 3, bool L2gradient = false)
.. ocv:function:: void gpu::Canny(const GpuMat& dx, const GpuMat& dy, GpuMat& edges, double low_thresh, double high_thresh, bool L2gradient = false)
.. ocv:function:: void gpu::Canny(const GpuMat& dx, const GpuMat& dy, CannyBuf& buf, GpuMat& edges, double low_thresh, double high_thresh, bool L2gradient = false)
:param image: Single-channel 8-bit input image.
:param dx: First derivative of image in the vertical direction. Support only ``CV_32S`` type.
:param dy: First derivative of image in the horizontal direction. Support only ``CV_32S`` type.
:param edges: Output edge map. It has the same size and type as ``image`` .
:param low_thresh: First threshold for the hysteresis procedure.
:param high_thresh: Second threshold for the hysteresis procedure.
:param apperture_size: Aperture size for the :ocv:func:`Sobel` operator.
:param L2gradient: Flag indicating whether a more accurate :math:`L_2` norm :math:`=\sqrt{(dI/dx)^2 + (dI/dy)^2}` should be used to compute the image gradient magnitude ( ``L2gradient=true`` ), or a faster default :math:`L_1` norm :math:`=|dI/dx|+|dI/dy|` is enough ( ``L2gradient=false`` ).
:param buf: Optional buffer to avoid extra memory allocations (for many calls with the same sizes).
.. seealso:: :ocv:func:`Canny`
gpu::bilateralFilter
--------------------
Performs bilateral filtering of passed image
.. ocv:function:: void gpu::bilateralFilter( const GpuMat& src, GpuMat& dst, int kernel_size, float sigma_color, float sigma_spatial, int borderMode=BORDER_DEFAULT, Stream& stream=Stream::Null() )
:param src: Source image. Supports only (channles != 2 && depth() != CV_8S && depth() != CV_32S && depth() != CV_64F).
:param dst: Destination imagwe.
:param kernel_size: Kernel window size.
:param sigma_color: Filter sigma in the color space.
:param sigma_spatial: Filter sigma in the coordinate space.
:param borderMode: Border type. See :ocv:func:`borderInterpolate` for details. ``BORDER_REFLECT101`` , ``BORDER_REPLICATE`` , ``BORDER_CONSTANT`` , ``BORDER_REFLECT`` and ``BORDER_WRAP`` are supported for now.
:param stream: Stream for the asynchronous version.
.. seealso::
:ocv:func:`bilateralFilter`
gpu::blendLinear
-------------------
Performs linear blending of two images.
.. ocv:function:: void gpu::blendLinear(const GpuMat& img1, const GpuMat& img2, const GpuMat& weights1, const GpuMat& weights2, GpuMat& result, Stream& stream = Stream::Null())
:param img1: First image. Supports only ``CV_8U`` and ``CV_32F`` depth.
:param img2: Second image. Must have the same size and the same type as ``img1`` .
:param weights1: Weights for first image. Must have tha same size as ``img1`` . Supports only ``CV_32F`` type.
:param weights2: Weights for second image. Must have tha same size as ``img2`` . Supports only ``CV_32F`` type.
:param result: Destination image.
:param stream: Stream for the asynchronous version.