mirror of https://github.com/opencv/opencv.git
Open Source Computer Vision Library
https://opencv.org/
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
188 lines
6.5 KiB
188 lines
6.5 KiB
Matrix Reductions |
|
================= |
|
|
|
.. highlight:: cpp |
|
|
|
|
|
|
|
gpu::meanStdDev |
|
------------------- |
|
Computes a mean value and a standard deviation of matrix elements. |
|
|
|
.. ocv:function:: void gpu::meanStdDev(const GpuMat& mtx, Scalar& mean, Scalar& stddev) |
|
|
|
:param mtx: Source matrix. ``CV_8UC1`` matrices are supported for now. |
|
|
|
:param mean: Mean value. |
|
|
|
:param stddev: Standard deviation value. |
|
|
|
.. seealso:: :ocv:func:`meanStdDev` |
|
|
|
|
|
|
|
gpu::norm |
|
------------- |
|
Returns the norm of a matrix (or difference of two matrices). |
|
|
|
.. ocv:function:: double gpu::norm(const GpuMat& src1, int normType=NORM_L2) |
|
|
|
.. ocv:function:: double gpu::norm(const GpuMat& src1, int normType, GpuMat& buf) |
|
|
|
.. ocv:function:: double gpu::norm(const GpuMat& src1, const GpuMat& src2, int normType=NORM_L2) |
|
|
|
:param src1: Source matrix. Any matrices except 64F are supported. |
|
|
|
:param src2: Second source matrix (if any) with the same size and type as ``src1``. |
|
|
|
:param normType: Norm type. ``NORM_L1`` , ``NORM_L2`` , and ``NORM_INF`` are supported for now. |
|
|
|
:param buf: Optional buffer to avoid extra memory allocations. It is resized automatically. |
|
|
|
.. seealso:: :ocv:func:`norm` |
|
|
|
|
|
|
|
gpu::sum |
|
------------ |
|
Returns the sum of matrix elements. |
|
|
|
.. ocv:function:: Scalar gpu::sum(const GpuMat& src) |
|
|
|
.. ocv:function:: Scalar gpu::sum(const GpuMat& src, GpuMat& buf) |
|
|
|
:param src: Source image of any depth except for ``CV_64F`` . |
|
|
|
:param buf: Optional buffer to avoid extra memory allocations. It is resized automatically. |
|
|
|
.. seealso:: :ocv:func:`sum` |
|
|
|
|
|
|
|
gpu::absSum |
|
--------------- |
|
Returns the sum of absolute values for matrix elements. |
|
|
|
.. ocv:function:: Scalar gpu::absSum(const GpuMat& src) |
|
|
|
.. ocv:function:: Scalar gpu::absSum(const GpuMat& src, GpuMat& buf) |
|
|
|
:param src: Source image of any depth except for ``CV_64F`` . |
|
|
|
:param buf: Optional buffer to avoid extra memory allocations. It is resized automatically. |
|
|
|
|
|
|
|
gpu::sqrSum |
|
--------------- |
|
Returns the squared sum of matrix elements. |
|
|
|
.. ocv:function:: Scalar gpu::sqrSum(const GpuMat& src) |
|
|
|
.. ocv:function:: Scalar gpu::sqrSum(const GpuMat& src, GpuMat& buf) |
|
|
|
:param src: Source image of any depth except for ``CV_64F`` . |
|
|
|
:param buf: Optional buffer to avoid extra memory allocations. It is resized automatically. |
|
|
|
|
|
|
|
gpu::minMax |
|
--------------- |
|
Finds global minimum and maximum matrix elements and returns their values. |
|
|
|
.. ocv:function:: void gpu::minMax(const GpuMat& src, double* minVal, double* maxVal=0, const GpuMat& mask=GpuMat()) |
|
|
|
.. ocv:function:: void gpu::minMax(const GpuMat& src, double* minVal, double* maxVal, const GpuMat& mask, GpuMat& buf) |
|
|
|
:param src: Single-channel source image. |
|
|
|
:param minVal: Pointer to the returned minimum value. Use ``NULL`` if not required. |
|
|
|
:param maxVal: Pointer to the returned maximum value. Use ``NULL`` if not required. |
|
|
|
:param mask: Optional mask to select a sub-matrix. |
|
|
|
:param buf: Optional buffer to avoid extra memory allocations. It is resized automatically. |
|
|
|
The function does not work with ``CV_64F`` images on GPUs with the compute capability < 1.3. |
|
|
|
.. seealso:: :ocv:func:`minMaxLoc` |
|
|
|
|
|
|
|
gpu::minMaxLoc |
|
------------------ |
|
Finds global minimum and maximum matrix elements and returns their values with locations. |
|
|
|
.. ocv:function:: void gpu::minMaxLoc(const GpuMat& src, double* minVal, double* maxVal=0, Point* minLoc=0, Point* maxLoc=0, const GpuMat& mask=GpuMat()) |
|
|
|
.. ocv:function:: void gpu::minMaxLoc(const GpuMat& src, double* minVal, double* maxVal, Point* minLoc, Point* maxLoc, const GpuMat& mask, GpuMat& valbuf, GpuMat& locbuf) |
|
|
|
:param src: Single-channel source image. |
|
|
|
:param minVal: Pointer to the returned minimum value. Use ``NULL`` if not required. |
|
|
|
:param maxVal: Pointer to the returned maximum value. Use ``NULL`` if not required. |
|
|
|
:param minValLoc: Pointer to the returned minimum location. Use ``NULL`` if not required. |
|
|
|
:param maxValLoc: Pointer to the returned maximum location. Use ``NULL`` if not required. |
|
|
|
:param mask: Optional mask to select a sub-matrix. |
|
|
|
:param valbuf: Optional values buffer to avoid extra memory allocations. It is resized automatically. |
|
|
|
:param locbuf: Optional locations buffer to avoid extra memory allocations. It is resized automatically. |
|
|
|
The function does not work with ``CV_64F`` images on GPU with the compute capability < 1.3. |
|
|
|
.. seealso:: :ocv:func:`minMaxLoc` |
|
|
|
|
|
|
|
gpu::countNonZero |
|
--------------------- |
|
Counts non-zero matrix elements. |
|
|
|
.. ocv:function:: int gpu::countNonZero(const GpuMat& src) |
|
|
|
.. ocv:function:: int gpu::countNonZero(const GpuMat& src, GpuMat& buf) |
|
|
|
:param src: Single-channel source image. |
|
|
|
:param buf: Optional buffer to avoid extra memory allocations. It is resized automatically. |
|
|
|
The function does not work with ``CV_64F`` images on GPUs with the compute capability < 1.3. |
|
|
|
.. seealso:: :ocv:func:`countNonZero` |
|
|
|
|
|
|
|
gpu::reduce |
|
------ |
|
Reduces a matrix to a vector. |
|
|
|
.. ocv:function:: void gpu::reduce(const GpuMat& mtx, GpuMat& vec, int dim, int reduceOp, int dtype = -1, Stream& stream = Stream::Null()) |
|
|
|
:param mtx: Source 2D matrix. |
|
|
|
:param vec: Destination vector. Its size and type is defined by ``dim`` and ``dtype`` parameters. |
|
|
|
:param dim: Dimension index along which the matrix is reduced. 0 means that the matrix is reduced to a single row. 1 means that the matrix is reduced to a single column. |
|
|
|
:param reduceOp: Reduction operation that could be one of the following: |
|
|
|
* **CV_REDUCE_SUM** The output is the sum of all rows/columns of the matrix. |
|
|
|
* **CV_REDUCE_AVG** The output is the mean vector of all rows/columns of the matrix. |
|
|
|
* **CV_REDUCE_MAX** The output is the maximum (column/row-wise) of all rows/columns of the matrix. |
|
|
|
* **CV_REDUCE_MIN** The output is the minimum (column/row-wise) of all rows/columns of the matrix. |
|
|
|
:param dtype: When it is negative, the destination vector will have the same type as the source matrix. Otherwise, its type will be ``CV_MAKE_TYPE(CV_MAT_DEPTH(dtype), mtx.channels())`` . |
|
|
|
The function ``reduce`` reduces the matrix to a vector by treating the matrix rows/columns as a set of 1D vectors and performing the specified operation on the vectors until a single row/column is obtained. For example, the function can be used to compute horizontal and vertical projections of a raster image. In case of ``CV_REDUCE_SUM`` and ``CV_REDUCE_AVG`` , the output may have a larger element bit-depth to preserve accuracy. And multi-channel arrays are also supported in these two reduction modes. |
|
|
|
.. seealso:: :ocv:func:`reduce`
|
|
|