\section{Matrix Reductions}


\cvCppFunc{gpu::sum}
Returns sum of array elements.

\cvdefCpp{Scalar sum(const GpuMat\& src);\newline
Scalar sum(const GpuMat\& src, GpuMat\& buf);}

\begin{description}
\cvarg{src}{Source image of any depth excepting 64F, single-channel.}
\cvarg{buf}{Optional buffer. It's resized automatically.}
\end{description}

See also: \cvCppCross{sum}.


\cvCppFunc{gpu::sqrSum}
Returns squared sum of array elements.

\cvdefCpp{Scalar sqrSum(const GpuMat\& src);\newline
Scalar sqrSum(const GpuMat\& src, GpuMat\& buf);}
\begin{description}
\cvarg{src}{Source image of any depth excepting 64F, single-channel.}
\cvarg{buf}{Optional buffer. It's resized automatically.}
\end{description}


\cvCppFunc{gpu::minMax}
Finds global minimum and maximum array elements and returns their values.

\cvdefCpp{void minMax(const GpuMat\& src, double* minVal,\par
  double* maxVal=0, const GpuMat\& mask=GpuMat());\newline
void minMax(const GpuMat\& src, double* minVal, double* maxVal,\par
  const GpuMat\& mask, GpuMat\& buf);}
\begin{description}
\cvarg{src}{Single-channel source image.}
\cvarg{minVal}{Pointer to returned minimum value. \texttt{NULL} if not required.}
\cvarg{maxVal}{Pointer to returned maximum value. \texttt{NULL} if not required.}
\cvarg{mask}{Optional mask to select a sub-array.}
\cvarg{buf}{Optional buffer. It's resized automatically.}
\end{description}

Function doesn't work with 64F images on GPU with compute capability $<$ 1.3.\newline
See also: \cvCppCross{minMaxLoc}.


\cvCppFunc{gpu::minMaxLoc}
Finds global minimum and maximum array elements and returns their values with locations.

\cvdefCpp{void minMaxLoc(const GpuMat\& src, double\* minVal, double* maxVal=0,\par
  Point* minLoc=0, Point* maxLoc=0,\par
  const GpuMat\& mask=GpuMat());\newline
void minMaxLoc(const GpuMat\& src, double* minVal, double* maxVal,\par
  Point* minLoc, Point* maxLoc, const GpuMat\& mask,\par
  GpuMat\& valbuf, GpuMat\& locbuf);}
\begin{description}
\cvarg{src}{Single-channel source image.}
\cvarg{minVal}{Pointer to returned minimum value. \texttt{NULL} if not required.}
\cvarg{maxVal}{Pointer to returned maximum value. \texttt{NULL} if not required.}
\cvarg{minValLoc}{Pointer to returned minimum location. \texttt{NULL} if not required.}
\cvarg{maxValLoc}{Pointer to returned maximum location. \texttt{NULL} if not required.}
\cvarg{mask}{Optional mask to select a sub-array.}
\cvarg{valbuf}{Optional values buffer. It's resized automatically.}
\cvarg{locbuf}{Optional location buffer. It's resized automatically.}
\end{description}

Function doesn't work with 64F images on GPU with compute capability $<$ 1.3.\newline
See also: \cvCppCross{minMaxLoc}.


\cvCppFunc{gpu::countNonZero}
Counts non-zero array elements.

\cvdefCpp{int countNonZero(const GpuMat\& src);\newline
int countNonZero(const GpuMat\& src, GpuMat\& buf);}
\begin{description}
\cvarg{src}{Single-channel source image.}
\cvarg{buf}{Optional buffer. It's resized automatically.}
\end{description}

Function doesn't work with 64F images on GPU with compute capability $<$ 1.3.\newline
See also: \cvCppCross{countNonZero}.