Function gaussian1D

src/backend/opencl/kernel/sift.hpp:76–89

template<typename T>
void gaussian1D(T* out, const int dim, double sigma = 0.0) {
    if (!(sigma > 0)) sigma = 0.25 * dim;

    T sum = (T)0;
    for (int i = 0; i < dim; i++) {
        int x = i - (dim - 1) / 2;
        T el  = 1. / sqrt(2 * PI_VAL * sigma * sigma) *
               exp(-((x * x) / (2 * (sigma * sigma))));
        out[i] = el;
        sum += el;
    }

    for (int k = 0; k < dim; k++) out[k] /= sum;
}

template<typename T>
Param gaussFilter(float sigma) {