boost::gil::threshold_adaptive

template<
    typename SrcView,
    typename DstView>
void
threshold_adaptive(
    SrcView const& src_view,
    DstView const& dst_view,
    std::size_t kernel_size,
    threshold_adaptive_method method = threshold_adaptive_method::mean,
    threshold_direction direction = threshold_direction::regular,
    int constant = 0);