CFeatureExtraction.h

Go to the documentation of this file.

/* +---------------------------------------------------------------------------+
   |                     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 details in https://www.mrpt.org/License   |
   +---------------------------------------------------------------------------+
   */
#pragma once

#include <mrpt/img/CImage.h>
#include <mrpt/system/CTimeLogger.h>
#include <mrpt/vision/CFeature.h>
#include <mrpt/vision/TKeyPoint.h>
#include <mrpt/vision/utils.h>

namespace mrpt::vision
{
/** The central class from which images can be analyzed in search of different
 *kinds of interest points and descriptors computed for them.
 *  To extract features from an image, create an instance of
 *CFeatureExtraction,
 *   fill out its CFeatureExtraction::options field, including the algorithm to
 *use (see
 *   CFeatureExtraction::TOptions::featsType), and call
 *CFeatureExtraction::detectFeatures.
 *  This will return a set of features of the class mrpt::vision::CFeature,
 *which include
 *   details for each interest point as well as the desired descriptors and/or
 *patches.
 *
 *  By default, a 21x21 patch is extracted for each detected feature. If the
 *patch is not needed,
 *   set patchSize to 0 in CFeatureExtraction::options
 *
 *  The implemented <b>detection</b> algorithms are (see
 *CFeatureExtraction::TOptions::featsType):
 *      - KLT (Kanade-Lucas-Tomasi): A detector (no descriptor vector).
 *      - Harris: A detector (no descriptor vector).
 *      - BCD (Binary Corner Detector): A detector (no descriptor vector) (Not
 *implemented yet).
 *      - SIFT: An implementation of the SIFT detector and descriptor. The
 *implemention may be selected with
 *CFeatureExtraction::TOptions::SIFTOptions::implementation.
 *      - SURF: OpenCV's implementation of SURF detector and descriptor.
 *      - The FAST feature detector (OpenCV's implementation)
 *
 *  Additionally, given a list of interest points onto an image, the following
 *   <b>descriptors</b> can be computed for each point by calling
 *CFeatureExtraction::computeDescriptors :
 *      - SIFT descriptor (Lowe's descriptors).
 *      - SURF descriptor (OpenCV's implementation - Requires OpenCV 1.1.0 from
 *SVN
 *or later).
 *      - Intensity-domain spin images (SpinImage): Creates a vector descriptor
 *with the 2D histogram as a single row.
 *      - A circular patch in polar coordinates (Polar images): The matrix
 *descriptor is a 2D polar image centered at the interest point.
 *      - A log-polar image patch (Log-polar images): The matrix descriptor is
 *the
 *2D log-polar image centered at the interest point.
 *
 *
 * \note The descriptor "Intensity-domain spin images" is described in "A
 *sparse texture representation using affine-invariant regions", S Lazebnik, C
 *Schmid, J Ponce, 2003 IEEE Computer Society Conference on Computer Vision.
 * \sa mrpt::vision::CFeature
 * \ingroup mrptvision_features
 */
class CFeatureExtraction
{
   public:
    /** Timelogger: disabled by default */
    mrpt::system::CTimeLogger profiler{false};

    enum TSIFTImplementation
    {
        LoweBinary = 0 /* obsolete */,
        CSBinary /* obsolete */,
        VedaldiBinary /* obsolete */,
        Hess /* obsolete */,
        OpenCV /* DEFAULT */
    };

    /** The set of parameters for all the detectors & descriptor algorithms */
    struct TOptions : public mrpt::config::CLoadableOptions
    {
        TOptions() = default;
        TOptions(const TKeyPointMethod ft) : TOptions() { featsType = ft; }

        // See base docs
        void loadFromConfigFile(
            const mrpt::config::CConfigFileBase& c,
            const std::string& s) override;
        void dumpToTextStream(std::ostream& out) const override;

        /** Type of the extracted features */
        TKeyPointMethod featsType{featKLT};

        /** Size of the patch to extract, or 0 if no patch is desired
         * (default=21).
         */
        unsigned int patchSize{21};

        /** Whether to use a mask for determining the regions where not to look
         * for keypoints (default=false).
         */
        bool useMask{false};

        /** Whether to add the found features to the input feature list or clear
         * it before adding them (default=false).
         */
        bool addNewFeatures{false};

        /** Indicates if subpixel accuracy is desired for the extracted points
         * (only applicable to KLT and Harris features)
         */
        bool FIND_SUBPIXEL{true};

        /** KLT Options */
        struct TKLTOptions
        {
            /** size of the block of pixels used */
            int radius{5};
            /** (default=0.05f) for rejecting weak local maxima
             * (with min_eig < threshold*max(eig_image) */
            float threshold{0.05f};
            /** minimum distance between features */
            float min_distance{5.0f};
        } KLTOptions;

        /** Harris Options */
        struct THarrisOptions
        {
            /** (default=0.005) for rejecting weak local maxima
             * (with min_eig < threshold*max(eig_image)) */
            float threshold{0.005f};
            /** standard deviation for the gaussian smoothing function */
            float sigma{3.0f};
            /** size of the block of pixels used */
            int radius{3};
            /** minimum distance between features */
            float min_distance{5.0f};
            double k{0.04};
        } harrisOptions;

        /** BCD Options */
        struct TBCDOptions
        {
        } BCDOptions;

        /** FAST Options */
        struct TFASTOptions
        {
            /** default= 20 */
            int threshold = 20;
            /** (default=5) minimum distance between features (in pixels) */
            unsigned int min_distance = 5;
            /** Default = true */
            bool nonmax_suppression{true};
            /** (default=false) If true, use CImage::KLT_response to compute the
             * response at each point.
             */
            bool use_KLT_response{false};
            /** Used if use_KLT_response==true */
            int KLT_response_half_win_size{4};
        } FASTOptions;

        /** ORB Options */
        struct TORBOptions
        {
            TORBOptions() = default;
            size_t n_levels{1};
            size_t min_distance{0};
            float scale_factor{1.2f};
            bool extract_patch{false};
        } ORBOptions;

        /** SIFT Options  */
        struct TSIFTOptions
        {
            TSIFTOptions() = default;
            TSIFTImplementation implementation{OpenCV};  //!< Default: OpenCV
            int octaveLayers{3};
            double threshold{0.04};  //!< default= 0.04
            double edgeThreshold{10};  //!< default= 10
        } SIFTOptions;

        /** SURF Options */
        struct TSURFOptions
        {
            TSURFOptions() = default;

            /** Compute the rotation invariant SURF */
            bool rotation_invariant{true};
            int hessianThreshold{600};
            int nOctaves{2};
            int nLayersPerOctave{4};
        } SURFOptions;

        /** SpinImages Options */
        struct TSpinImagesOptions
        {
            /** Number of bins in the "intensity" axis of the 2D histogram
             * (default=10). */
            unsigned int hist_size_intensity{10};
            /** Number of bins in the "distance" axis of the 2D histogram
             * (default=10).*/
            unsigned int hist_size_distance{10};
            /** Standard deviation in "distance", used for the "soft histogram"
             * (default=0.4 pixels) */
            float std_dist{.4f};
            /** Standard deviation in "intensity", used for the "soft histogram"
             * (default=20 units [0,255]) */
            float std_intensity{20};
            /** Maximum radius of the area of which the histogram is built, in
             * pixel units (default=20 pixels) */
            unsigned int radius{20};
        } SpinImagesOptions;

        /** PolarImagesOptions options  */
        struct TPolarImagesOptions
        {
            /** Number of bins in the "angular" axis of the polar image
             * (default=8). */
            unsigned int bins_angle{8};
            /** Number of bins in the "distance" axis of the polar image
             * (default=6). */
            unsigned int bins_distance{6};
            /** Maximum radius of the area of which the polar image is built, in
             * pixel units (default=20 pixels) */
            unsigned int radius{20};
        } PolarImagesOptions;

        /** LogPolarImagesOptions Options
         */
        struct TLogPolarImagesOptions
        {
            /** Maximum radius of the area of which the log polar image is
             * built, in pixel units (default=30 pixels) */
            unsigned int radius{30};
            /** (default=16) Log-Polar image patch will have dimensions WxH,
             * with: W=num_angles,  H= rho_scale*log(radius) */
            unsigned int num_angles{16};
            /** (default=5) Log-Polar image patch will have dimensions WxH,
             * with:  W=num_angles,  H=rho_scale * log(radius) */
            double rho_scale{5};
        } LogPolarImagesOptions;

        // # added by Raghavender Sahdev
        /** AKAZEOptions Options */
        struct TAKAZEOptions
        {
            /** AKAZE::DESCRIPTOR_MLDB maps to 5 in open cv;
             * http://docs.opencv.org/trunk/d8/d30/classcv_1_1AKAZE.html */
            int descriptor_type{5};
            int descriptor_size{0};
            int descriptor_channels{3};
            float threshold{0.001f};
            int nOctaves{4};
            int nOctaveLayers{4};
            /** KAZE::DIFF_PM_G2 maps to 1;
             * http://docs.opencv.org/trunk/d3/d61/classcv_1_1KAZE.html */
            int diffusivity{1};
        } AKAZEOptions;

        /** LSDOptions Options */
        struct TLSDOptions
        {
            int scale{2};
            int nOctaves{1};
        } LSDOptions;

        /** BLDOptions Descriptor Options */
        struct TBLDOptions
        {
            int ksize_{11};
            int reductionRatio{2};
            int widthOfBand{7};
            int numOfOctave{1};
        } BLDOptions;

        /** LATCHOptions Descriptor */
        struct TLATCHOptions
        {
            int bytes{32};
            bool rotationInvariance{true};
            int half_ssd_size{3};
        } LATCHOptions;
    };

    /** Set all the parameters of the desired method here before calling
     * detectFeatures() */
    TOptions options;

    /** Extract features from the image based on the method defined in
     * TOptions. \param img (input) The image from where to extract the
     * images. \param feats (output) A complete list of features (containing
     * a patch for each one of them if options.patchsize > 0). \param
     * nDesiredFeatures (op. input) Number of features to be extracted.
     * Default: all possible.
     *
     * \sa computeDescriptors
     */
    void detectFeatures(
        const mrpt::img::CImage& img, CFeatureList& feats,
        const unsigned int init_ID = 0, const unsigned int nDesiredFeatures = 0,
        const TImageROI& ROI = TImageROI());

    /** Compute one (or more) descriptors for the given set of interest
     * points onto the image, which may have been filled out manually or
     * from \a detectFeatures \param in_img (input) The image from where to
     * compute the descriptors. \param inout_features (input/output) The
     * list of features whose descriptors are going to be computed. \param
     * in_descriptor_list (input) The bitwise OR of one or several
     * descriptors defined in TDescriptorType.
     *
     *  Each value in "in_descriptor_list" represents one descriptor to be
     * computed, for example:
     *  \code
     *    // This call will compute both, SIFT and Spin-Image descriptors
     * for a list of feature points lstFeats. fext.computeDescriptors(img,
     * lstFeats, descSIFT | descSpinImages ); \endcode
     *
     * \note The SIFT descriptors for already located features can only be
     * computed through the Hess and
     *        CSBinary implementations which may be specified in
     * CFeatureExtraction::TOptions::SIFTOptions.
     *
     * \note This call will also use additional parameters from \a options
     */
    void computeDescriptors(
        const mrpt::img::CImage& in_img, CFeatureList& inout_features,
        TDescriptorType in_descriptor_list);

   private:
    /** Compute the SIFT descriptor of the provided features into the input
    image
    * \param in_img (input) The image from where to compute the descriptors.
    * \param in_features (input/output) The list of features whose
    descriptors are going to be computed.
    *
    * \note The SIFT descriptors for already located features can only be
    computed through the Hess and
            CSBinary implementations which may be specified in
    CFeatureExtraction::TOptions::SIFTOptions.
    */
    void internal_computeSiftDescriptors(
        const mrpt::img::CImage& in_img, CFeatureList& in_features);

    /** Compute the SURF descriptor of the provided features into the input
     * image
     * \param in_img (input) The image from where to compute the
     * descriptors. \param in_features (input/output) The list of features
     * whose descriptors are going to be computed.
     */
    void internal_computeSurfDescriptors(
        const mrpt::img::CImage& in_img, CFeatureList& in_features);

    /** Compute the ORB descriptor of the provided features into the input
     * image \param in_img (input) The image from where to compute the
     * descriptors. \param in_features (input/output) The list of features
     * whose descriptors are going to be computed.
     */
    void internal_computeORBDescriptors(
        const mrpt::img::CImage& in_img, CFeatureList& in_features);

    /** Compute the intensity-domain spin images descriptor of the provided
     * features into the input image
     * \param in_img (input) The image from where to compute the
     * descriptors. \param in_features (input/output) The list of features
     * whose descriptors are going to be computed.
     *
     * \note Additional parameters from
     * CFeatureExtraction::TOptions::SpinImagesOptions are used in this
     * method.
     */
    void internal_computeSpinImageDescriptors(
        const mrpt::img::CImage& in_img, CFeatureList& in_features);

    /** Compute a polar-image descriptor of the provided features into the
     * input image \param in_img (input) The image from where to compute the
     * descriptors. \param in_features (input/output) The list of features
     * whose descriptors are going to be computed.
     *
     * \note Additional parameters from
     * CFeatureExtraction::TOptions::PolarImagesOptions are used in this
     * method.
     */
    void internal_computePolarImageDescriptors(
        const mrpt::img::CImage& in_img, CFeatureList& in_features);

    /** Compute a log-polar image descriptor of the provided features into
     * the input image \param in_img (input) The image from where to compute
     * the descriptors. \param in_features (input/output) The list of
     * features whose descriptors are going to be computed.
     *
     * \note Additional parameters from
     * CFeatureExtraction::TOptions::LogPolarImagesOptions are used in this
     * method.
     */
    void internal_computeLogPolarImageDescriptors(
        const mrpt::img::CImage& in_img, CFeatureList& in_features);
    /** Compute a BLD descriptor of the provided features into the input
     * image \param in_img (input) The image from where to compute the
     * descriptors. \param in_features (input/output) The list of features
     * whose descriptors are going to be computed.
     *
     * \note Additional parameters from
     * CFeatureExtraction::TOptions::LogPolarImagesOptions are used in this
     * method.
     */
    void internal_computeBLDLineDescriptors(
        const mrpt::img::CImage& in_img, CFeatureList& in_features);
    /** Compute a LATCH descriptor of the provided features into the input
     * image \param in_img (input) The image from where to compute the
     * descriptors. \param in_features (input/output) The list of features
     * whose descriptors are going to be computed.
     *
     * \note Additional parameters from
     * CFeatureExtraction::TOptions::LogPolarImagesOptions are used in this
     * method.
     */
    void internal_computeLATCHDescriptors(
        const mrpt::img::CImage& in_img, CFeatureList& in_features);

    /** Extract features from the image based on the KLT method.
     * \param img The image from where to extract the images.
     * \param feats The list of extracted features.
     * \param nDesiredFeatures Number of features to be extracted. Default:
     * authomatic.
     */
    void extractFeaturesKLT(
        const mrpt::img::CImage& img, CFeatureList& feats,
        unsigned int init_ID = 0, unsigned int nDesiredFeatures = 0,
        const TImageROI& ROI = TImageROI());

    // ------------------------------------------------------------------------------------
    //                                          SIFT
    // ------------------------------------------------------------------------------------
    /** Extract features from the image based on the SIFT method.
     * \param img The image from where to extract the images.
     * \param feats The list of extracted features.
     * \param nDesiredFeatures Number of features to be extracted. Default:
     * authomatic.
     * \param ROI (op. input) Region of Interest. Default: All the image.
     */
    void extractFeaturesSIFT(
        const mrpt::img::CImage& img, CFeatureList& feats,
        unsigned int init_ID = 0, unsigned int nDesiredFeatures = 0,
        const TImageROI& ROI = TImageROI());

    // ------------------------------------------------------------------------------------
    //                                          ORB
    // ------------------------------------------------------------------------------------
    /** Extract features from the image based on the ORB method.
     * \param img The image from where to extract the images.
     * \param feats The list of extracted features.
     * \param nDesiredFeatures Number of features to be extracted. Default:
     * authomatic.
     */
    void extractFeaturesORB(
        const mrpt::img::CImage& img, CFeatureList& feats,
        const unsigned int init_ID = 0, const unsigned int nDesiredFeatures = 0,
        const TImageROI& ROI = TImageROI());

    // ------------------------------------------------------------------------------------
    //                                          SURF
    // ------------------------------------------------------------------------------------
    /** Extract features from the image based on the SURF method.
     * \param img The image from where to extract the images.
     * \param feats The list of extracted features.
     * \param nDesiredFeatures Number of features to be extracted. Default:
     * authomatic.
     */
    void extractFeaturesSURF(
        const mrpt::img::CImage& img, CFeatureList& feats,
        unsigned int init_ID = 0, unsigned int nDesiredFeatures = 0,
        const TImageROI& ROI = TImageROI());

    // ------------------------------------------------------------------------------------
    //                                          FAST
    // ------------------------------------------------------------------------------------
    /** Extract features from the image based on the FAST method (OpenCV impl.)
     * \param img The image from where to extract the images.
     * \param feats The list of extracted features.
     * \param nDesiredFeatures Number of features to be extracted. Default:
     * authomatic.
     */
    void extractFeaturesFAST(
        const mrpt::img::CImage& img, CFeatureList& feats,
        unsigned int init_ID = 0, unsigned int nDesiredFeatures = 0);

    // # added by Raghavender Sahdev
    //-------------------------------------------------------------------------------------
    //                               AKAZE
    //-------------------------------------------------------------------------------------
    /** Extract features from the image based on the AKAZE method.
     * \param img The image from where to extract the images.
     * \param feats The list of extracted features.
     * \param nDesiredFeatures Number of features to be extracted. Default:
     * authomatic.
     */
    void extractFeaturesAKAZE(
        const mrpt::img::CImage& inImg, CFeatureList& feats,
        unsigned int init_ID, unsigned int nDesiredFeatures,
        const TImageROI& ROI = TImageROI());

    //-------------------------------------------------------------------------------------
    //                               LSD
    //-------------------------------------------------------------------------------------
    /** Extract features from the image based on the LSD method.
     * \param img The image from where to extract the images.
     * \param feats The list of extracted features.
     * \param nDesiredFeatures Number of features to be extracted. Default:
     * authomatic.
     */
    void extractFeaturesLSD(
        const mrpt::img::CImage& inImg, CFeatureList& feats,
        unsigned int init_ID, unsigned int nDesiredFeatures,
        const TImageROI& ROI = TImageROI());

};  // end of class
}  // namespace mrpt::vision