/*******************************************************

* Copyright (c) 2015, ArrayFire

* All rights reserved.

*

* This file is distributed under 3-clause BSD license.

* The complete license agreement can be obtained at:

* http://arrayfire.com/licenses/BSD-3-Clause

********************************************************/

#include <Array.hpp>

#include <arith.hpp>

#include <err_cuda.hpp>

#include <kernel/homography.hpp>

#include <af/dim4.hpp>

#include <algorithm>

#include <limits>

using af::dim4;

namespace arrayfire {

namespace cuda {

#define RANSACConfidence 0.99f

#define LMEDSConfidence 0.99f

#define LMEDSOutlierRatio 0.4f

template<typename T>

int homography(Array<T> &bestH, const Array<float> &x_src,

const Array<float> &y_src, const Array<float> &x_dst,

const Array<float> &y_dst, const Array<float> &initial,

const af_homography_type htype, const float inlier_thr,

const unsigned iterations) {

const af::dim4 idims = x_src.dims();

const unsigned nsamples = idims[0];

unsigned iter = iterations;

Array<float> err = createEmptyArray<float>(dim4());

if (htype == AF_HOMOGRAPHY_LMEDS) {

iter = ::std::min(

iter, (unsigned)(log(1.f - LMEDSConfidence) /

log(1.f - pow(1.f - LMEDSOutlierRatio, 4.f))));

err = createValueArray<float>(af::dim4(nsamples, iter),

std::numeric_limits<float>::max());

}

af::dim4 rdims(4, iter);

Array<float> fctr = createValueArray<float>(rdims, (float)nsamples);

Array<float> rnd = arithOp<float, af_mul_t>(initial, fctr, rdims);

Array<T> tmpH = createValueArray<T>(af::dim4(9, iter), (T)0);

return kernel::computeH<T>(bestH, tmpH, err, x_src, y_src, x_dst, y_dst,

rnd, iter, nsamples, inlier_thr, htype);

}

#define INSTANTIATE(T) \

template int homography<T>( \

Array<T> & H, const Array<float> &x_src, const Array<float> &y_src, \

const Array<float> &x_dst, const Array<float> &y_dst, \

const Array<float> &initial, const af_homography_type htype, \

const float inlier_thr, const unsigned iterations);

INSTANTIATE(float)

INSTANTIATE(double)

} // namespace cuda

} // namespace arrayfire