pub fn reduce(
src: &dyn ToInputArray,
dst: &mut dyn ToOutputArray,
dim: i32,
rtype: i32,
dtype: i32
) -> Result<()>Expand description
Reduces a matrix to a vector.
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 #REDUCE_MAX and #REDUCE_MIN , the output image should have the same type as the source one. In case of #REDUCE_SUM and #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.
The following code demonstrates its usage for a single channel matrix. example
And the following code demonstrates its usage for a two-channel matrix. example2
Parameters
- src: input 2D matrix.
- dst: output vector. Its size and type is defined by dim and dtype parameters.
- 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.
- rtype: reduction operation that could be one of #ReduceTypes
- dtype: when negative, the output vector will have the same type as the input matrix, otherwise, its type will be CV_MAKE_TYPE(CV_MAT_DEPTH(dtype), src.channels()).
See also
repeat, reduceArgMin, reduceArgMax
C++ default parameters
- dtype: -1