:param minVal:Pointer to returned minimum value, should not be NULL
:param maxVal:Pointer to returned maximum value, should not be NULL
:param minLoc:Pointer to returned minimum location (in 2D case), should not be NULL
:param maxLoc:Pointer to returned maximum location (in 2D case) should not be NULL
:param mask:The optional mask used to select a sub-array
The functions minMaxLoc find minimum and maximum element values and their positions. The extremums are searched across the whole array, or, if mask is not an empty array, in the specified array region. The functions do not work with multi-channel arrays.