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FEAT: Adding gaussian kernel to all backends
1 parent 78d41ec commit d21b107

4 files changed

Lines changed: 130 additions & 0 deletions

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‎include/af/compatible.h‎

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@@ -9,6 +9,7 @@
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#pragma once
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#include <af/array.h>
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#include <af/image.h>
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#ifdef __cplusplus
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namespace af
@@ -24,5 +25,8 @@ AFAPI array loadimage(const char* filename, const bool is_color=false);
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AFAPI void saveimage(const char* filename, const array& in);
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AFAPI array gaussiankernel(const int rows, const int cols, const double sig_r = 0, const double sig_c = 0);
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}
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#endif

‎include/af/image.h‎

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@@ -74,6 +74,8 @@ AFAPI array gray2rgb(const array& in, const float rFactor=1.0, const float gFact
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AFAPI array histequal(const array& in, const array& hist);
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AFAPI array gaussianKernel(const int rows, const int cols, const double sig_r = 0, const double sig_c = 0);
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}
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#endif
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@@ -155,6 +157,10 @@ extern "C" {
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AFAPI af_err af_histequal(af_array *out, const af_array in, const af_array hist);
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AFAPI af_err af_gaussian_kernel(af_array *out,
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const int rows, const int cols,
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const double sigma_r, const double sigma_c);
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#ifdef __cplusplus
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}
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#endif

‎src/api/c/gaussian_kernel.cpp‎

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/*******************************************************
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* Copyright (c) 2014, ArrayFire
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* All rights reserved.
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*
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* This file is distributed under 3-clause BSD license.
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* The complete license agreement can be obtained at:
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* http://arrayfire.com/licenses/BSD-3-Clause
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********************************************************/
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#include <af/dim4.hpp>
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#include <af/defines.h>
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#include <af/image.h>
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#include <err_common.hpp>
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#include <backend.hpp>
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#include <handle.hpp>
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#include <reduce.hpp>
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#include <arith.hpp>
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#include <math.hpp>
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#include <unary.hpp>
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#include <iota.hpp>
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#include <reduce.hpp>
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#include <transpose.hpp>
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using namespace detail;
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template<typename T>
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Array<T> gaussianKernel(const int rows, const int cols, const double sigma_r, const double sigma_c)
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{
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const dim4 odims = dim4(rows, cols);
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double sigma = 0;
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Array<T> tmp = createValueArray<T>(odims, scalar<T>(0));
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Array<T> half = createValueArray<T>(odims, 0.5);
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Array<T> zero = createValueArray<T>(odims, scalar<T>(0));
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if (cols > 1) {
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Array<T> wt = iota<T>(dim4(cols, rows), 0);
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Array<T> w = transpose<T>(wt, false);
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Array<T> c = createValueArray<T>(odims, scalar<T>((double)(cols - 1) / 2.0));
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w = arithOp<T, af_sub_t>(w, c, odims);
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sigma = sigma_c > 0 ? sigma_c : 0.25 * cols;
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Array<T> sig = createValueArray<T>(odims, sigma);
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w = arithOp<T, af_div_t>(w, sig, odims);
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w = arithOp<T, af_mul_t>(w, w, odims);
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tmp = arithOp<T, af_add_t>(w, tmp, odims);
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}
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if (rows > 1) {
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Array<T> w = iota<T>(dim4(rows, cols), 0);
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Array<T> r = createValueArray<T>(odims, scalar<T>((double)(rows - 1) / 2.0));
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w = arithOp<T, af_sub_t>(w, r, odims);
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sigma = sigma_r > 0 ? sigma_r : 0.25 * rows;
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Array<T> sig = createValueArray<T>(odims, sigma);
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w = arithOp<T, af_div_t>(w, sig, odims);
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w = arithOp<T, af_mul_t>(w, w, odims);
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tmp = arithOp<T, af_add_t>(w, tmp, odims);
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}
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tmp = arithOp<T, af_mul_t>(half, tmp, odims);
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tmp = arithOp<T, af_sub_t>(zero, tmp, odims);
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tmp = unaryOp<T, af_exp_t>(tmp);
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// Use this instead of (2 * pi * sig^2);
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// This ensures the window adds up to 1
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T norm_factor = reduce_all<af_add_t, T, T>(tmp);
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Array<T> norm = createValueArray(odims, norm_factor);
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Array<T> res = arithOp<T, af_div_t>(tmp, norm, odims);
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return res;
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}
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af_err af_gaussian_kernel(af_array *out,
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const int rows, const int cols,
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const double sigma_r, const double sigma_c)
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{
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af_array res;
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try {
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res = getHandle<float>(gaussianKernel<float>(rows, cols, sigma_r, sigma_c));
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std::swap(*out, res);
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}CATCHALL;
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return AF_SUCCESS;
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}

‎src/api/cpp/gaussian_kernel.cpp‎

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/*******************************************************
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* Copyright (c) 2014, ArrayFire
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* All rights reserved.
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*
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* This file is distributed under 3-clause BSD license.
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* The complete license agreement can be obtained at:
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* http://arrayfire.com/licenses/BSD-3-Clause
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********************************************************/
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#include <af/dim4.hpp>
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#include <af/image.h>
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#include <af/algorithm.h>
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#include <af/compatible.h>
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#include "error.hpp"
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namespace af{
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array gaussianKernel(const int rows, const int cols,
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const double sig_r, const double sig_c)
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{
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af_array res;
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AF_THROW(af_gaussian_kernel(&res, rows, cols, sig_r, sig_c));
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return array(res);
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}
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// Compatible function
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array gaussiankernel(const int rows, const int cols,
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const double sig_r, const double sig_c)
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{
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return gaussianKernel(rows, cols, sig_r, sig_c);
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}
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}

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