OpenCv计算直方图cv::calcHist

/** @brief Calculates a histogram of a set of arrays.
The functions calcHist calculate the histogram of one or more arrays. The elements of a tuple used
to increment a histogram bin are taken from the corresponding input arrays at the same location. The
sample below shows how to compute a 2D Hue-Saturation histogram for a color image.
**/
CV_EXPORTS void calcHist( const Mat* images, int nimages,
const int* channels, InputArray mask,
OutputArray hist, int dims, const int* histSize,
const float** ranges, bool uniform = true, bool accumulate = false );

/** @overloadthis variant uses cv::SparseMat for output*/
CV_EXPORTS void calcHist( const Mat* images, int nimages,
const int* channels, InputArray mask,
SparseMat& hist, int dims, const int* histSize,
const float** ranges, bool uniform = true, bool accumulate = false );

/** @overload */
CV_EXPORTS_W void calcHist( InputArrayOfArrays images,
const std::vector& channels, InputArray mask,
OutputArray hist, const std::vector& histSize,
const std::vector& ranges, bool accumulate = false );