| 34 | |
| 35 | template<typename T> |
| 36 | Array<T> gaussianKernel(const int rows, const int cols, const double sigma_r, |
| 37 | const double sigma_c) { |
| 38 | const dim4 odims = dim4(rows, cols); |
| 39 | double sigma = 0; |
| 40 | |
| 41 | Array<T> tmp = createValueArray<T>(odims, scalar<T>(0)); |
| 42 | Array<T> half = createValueArray<T>(odims, 0.5); |
| 43 | Array<T> zero = createValueArray<T>(odims, scalar<T>(0)); |
| 44 | |
| 45 | if (cols > 1) { |
| 46 | Array<T> wt = range<T>(dim4(cols, rows), 0); |
| 47 | Array<T> w = transpose<T>(wt, false); |
| 48 | |
| 49 | Array<T> c = createValueArray<T>( |
| 50 | odims, scalar<T>(static_cast<double>(cols - 1) / 2.0)); |
| 51 | w = arithOp<T, af_sub_t>(w, c, odims); |
| 52 | |
| 53 | sigma = sigma_c > 0 ? sigma_c : 0.25 * cols; |
| 54 | Array<T> sig = createValueArray<T>(odims, sigma); |
| 55 | w = arithOp<T, af_div_t>(w, sig, odims); |
| 56 | |
| 57 | w = arithOp<T, af_mul_t>(w, w, odims); |
| 58 | tmp = arithOp<T, af_add_t>(w, tmp, odims); |
| 59 | } |
| 60 | |
| 61 | if (rows > 1) { |
| 62 | Array<T> w = range<T>(dim4(rows, cols), 0); |
| 63 | |
| 64 | Array<T> r = createValueArray<T>( |
| 65 | odims, scalar<T>(static_cast<double>(rows - 1) / 2.0)); |
| 66 | w = arithOp<T, af_sub_t>(w, r, odims); |
| 67 | |
| 68 | sigma = sigma_r > 0 ? sigma_r : 0.25 * rows; |
| 69 | Array<T> sig = createValueArray<T>(odims, sigma); |
| 70 | |
| 71 | w = arithOp<T, af_div_t>(w, sig, odims); |
| 72 | w = arithOp<T, af_mul_t>(w, w, odims); |
| 73 | tmp = arithOp<T, af_add_t>(w, tmp, odims); |
| 74 | } |
| 75 | |
| 76 | tmp = arithOp<T, af_mul_t>(half, tmp, odims); |
| 77 | tmp = arithOp<T, af_sub_t>(zero, tmp, odims); |
| 78 | tmp = unaryOp<T, af_exp_t>(tmp); |
| 79 | |
| 80 | // Use this instead of (2 * pi * sig^2); |
| 81 | // This ensures the window adds up to 1 |
| 82 | T norm_factor = getScalar<T>(reduce_all<af_add_t, T, T>(tmp)); |
| 83 | |
| 84 | Array<T> norm = createValueArray(odims, norm_factor); |
| 85 | Array<T> res = arithOp<T, af_div_t>(tmp, norm, odims); |
| 86 | |
| 87 | return res; |
| 88 | } |
| 89 | |
| 90 | af_err af_gaussian_kernel(af_array *out, const int rows, const int cols, |
| 91 | const double sigma_r, const double sigma_c) { |
no test coverage detected