CFeatureExtraction_AKAZE.cpp

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          https://www.mrpt.org/                         |
   |                                                                        |
   | Copyright (c) 2005-2020, Individual contributors, see AUTHORS file     |
   | See: https://www.mrpt.org/Authors - All rights reserved.               |
   | Released under BSD License. See: https://www.mrpt.org/License          |
   +------------------------------------------------------------------------+ */

/*---------------------------------------------------------------
    APPLICATION: CFeatureExtraction
    FILE: CFeatureExtraction_AKAZE.cpp
    AUTHOR: Raghavender Sahdev <raghavendersahdev@gmail.com>
  ---------------------------------------------------------------*/

#include "vision-precomp.h"  // Precompiled headers
// Universal include for all versions of OpenCV
#include <mrpt/3rdparty/do_opencv_includes.h>

#include <mrpt/io/CMemoryStream.h>
#include <mrpt/system/os.h>
#include <mrpt/vision/CFeatureExtraction.h>  // important import

using namespace mrpt::vision;
using namespace mrpt::img;
using namespace mrpt::math;
using namespace mrpt::img;
using namespace mrpt;
using namespace std;

void CFeatureExtraction::extractFeaturesAKAZE(
    const mrpt::img::CImage& inImg, CFeatureList& feats, unsigned int init_ID,
    unsigned int nDesiredFeatures, [[maybe_unused]] const TImageROI& ROI)
{
    MRPT_START
    mrpt::system::CTimeLoggerEntry tle(profiler, "extractFeaturesAKAZE");

#if MRPT_HAS_OPENCV
#if MRPT_OPENCV_VERSION_NUM < 0x300
    THROW_EXCEPTION("This function requires OpenCV > 3.0.0");
#else

    using namespace cv;
    vector<KeyPoint> cv_feats;  // The opencv keypoint output vector
    // Make sure we operate on a gray-scale version of the image:
    const CImage inImg_gray(inImg, FAST_REF_OR_CONVERT_TO_GRAY);

#if MRPT_OPENCV_VERSION_NUM >= 0x300

    Mat theImg = inImg_gray.asCvMat<Mat>(SHALLOW_COPY);
    Ptr<AKAZE> akaze = AKAZE::create(
#if MRPT_OPENCV_VERSION_NUM >= 0x400
        static_cast<cv::AKAZE::DescriptorType>(
            options.AKAZEOptions.descriptor_type),
#else
        options.AKAZEOptions.descriptor_type,
#endif
        options.AKAZEOptions.descriptor_size,
        options.AKAZEOptions.descriptor_channels,
        options.AKAZEOptions.threshold, options.AKAZEOptions.nOctaves,
        options.AKAZEOptions.nOctaveLayers,
#if MRPT_OPENCV_VERSION_NUM >= 0x400
        static_cast<cv::KAZE::DiffusivityType>(options.AKAZEOptions.diffusivity)
#else
        options.AKAZEOptions.diffusivity
#endif
    );

    akaze->detect(theImg, cv_feats);

    // *All* the features have been extracted.
    const size_t N = cv_feats.size();

#endif
    // sort the AKAZE features by line length
    for (size_t i = 0; i < N; i++)
    {
        for (size_t j = i + 1; j < N; j++)
        {
            if (cv_feats.at(j).response > cv_feats.at(i).response)
            {
                KeyPoint temp_point = cv_feats.at(i);
                cv_feats.at(i) = cv_feats.at(j);
                cv_feats.at(j) = temp_point;
            }
        }
    }

    unsigned int nMax =
        (nDesiredFeatures != 0 && N > nDesiredFeatures) ? nDesiredFeatures : N;
    const int offset = (int)this->options.patchSize / 2 + 1;
    const size_t size_2 = options.patchSize / 2;
    const size_t imgH = inImg.getHeight();
    const size_t imgW = inImg.getWidth();
    unsigned int i = 0;
    unsigned int cont = 0;
    TFeatureID nextID = init_ID;

    if (!options.addNewFeatures) feats.clear();

    while (cont != nMax && i != N)
    {
        // Take the next feature from the ordered list of good features:
        const KeyPoint& kp = cv_feats[i];
        i++;

        // Patch out of the image??
        const int xBorderInf = (int)floor(kp.pt.x - size_2);
        const int xBorderSup = (int)floor(kp.pt.x + size_2);
        const int yBorderInf = (int)floor(kp.pt.y - size_2);
        const int yBorderSup = (int)floor(kp.pt.y + size_2);

        if (!(xBorderSup < (int)imgW && xBorderInf > 0 &&
              yBorderSup < (int)imgH && yBorderInf > 0))
            continue;  // nope, skip.

        // All tests passed: add new feature:
        CFeature ft;
        ft.type = featAKAZE;
        ft.keypoint.ID = nextID++;
        ft.keypoint.pt.x = kp.pt.x;
        ft.keypoint.pt.y = kp.pt.y;
        ft.response = kp.response;
        ft.orientation = kp.angle;
        ft.keypoint.octave = kp.octave;
        ft.patchSize = options.patchSize;  // The size of the feature patch

        if (options.patchSize > 0)
        {
            ft.patch.emplace();
            inImg.extract_patch(
                *ft.patch, round(kp.pt.x) - offset, round(kp.pt.y) - offset,
                options.patchSize,
                options.patchSize);  // Image patch surronding the feature
        }
        feats.emplace_back(std::move(ft));
        ++cont;
    }

#endif
#endif
    MRPT_END
}