compute_derivative_kernels  296 modules/features2d/src/kaze/nldiffusion_functions.cpp     compute_derivative_kernels(kx, ky, xorder, yorder, scale);
compute_derivative_kernels   33 modules/features2d/src/kaze/nldiffusion_functions.h void compute_derivative_kernels(cv::OutputArray _kx, cv::OutputArray _ky, int dx, int dy, int scale);