// This file is part of OpenCV project.
// It is subject to the license terms in the LICENSE file found in the top-level directory
// of this distribution and at http://opencv.org/license.html.

// Copyright (c) 2011,2012. Philipp Wagner <bytefish[at]gmx[dot]de>.
// Third party copyrights are property of their respective owners.

#ifndef __OPENCV_FACEREC_HPP__
#define __OPENCV_FACEREC_HPP__

#include "opencv2/face.hpp"
#include "opencv2/core.hpp"

namespace cv { namespace face {

//! @addtogroup face
//! @{

// base for two classes
class CV_EXPORTS_W BasicFaceRecognizer : public FaceRecognizer
{
public:
    /** @see setNumComponents */
    CV_WRAP int getNumComponents() const;
    /** @copybrief getNumComponents @see getNumComponents */
    CV_WRAP void setNumComponents(int val);
    /** @see setThreshold */
    CV_WRAP double getThreshold() const CV_OVERRIDE;
    /** @copybrief getThreshold @see getThreshold */
    CV_WRAP void setThreshold(double val) CV_OVERRIDE;
    CV_WRAP std::vector<cv::Mat> getProjections() const;
    CV_WRAP cv::Mat getLabels() const;
    CV_WRAP cv::Mat getEigenValues() const;
    CV_WRAP cv::Mat getEigenVectors() const;
    CV_WRAP cv::Mat getMean() const;

    virtual void read(const FileNode& fn) CV_OVERRIDE;
    virtual void write(FileStorage& fs) const CV_OVERRIDE;
    virtual bool empty() const CV_OVERRIDE;

    using FaceRecognizer::read;
    using FaceRecognizer::write;

protected:
    int _num_components;
    double _threshold;
    std::vector<Mat> _projections;
    Mat _labels;
    Mat _eigenvectors;
    Mat _eigenvalues;
    Mat _mean;
};

class CV_EXPORTS_W EigenFaceRecognizer : public BasicFaceRecognizer
{
public:
    /**
    @param num_components The number of components (read: Eigenfaces) kept for this Principal
    Component Analysis. As a hint: There's no rule how many components (read: Eigenfaces) should be
    kept for good reconstruction capabilities. It is based on your input data, so experiment with the
    number. Keeping 80 components should almost always be sufficient.
    @param threshold The threshold applied in the prediction.

    ### Notes:

    -   Training and prediction must be done on grayscale images, use cvtColor to convert between the
        color spaces.
    -   **THE EIGENFACES METHOD MAKES THE ASSUMPTION, THAT THE TRAINING AND TEST IMAGES ARE OF EQUAL
        SIZE.** (caps-lock, because I got so many mails asking for this). You have to make sure your
        input data has the correct shape, else a meaningful exception is thrown. Use resize to resize
        the images.
    -   This model does not support updating.

    ### Model internal data:

    -   num_components see EigenFaceRecognizer::create.
    -   threshold see EigenFaceRecognizer::create.
    -   eigenvalues The eigenvalues for this Principal Component Analysis (ordered descending).
    -   eigenvectors The eigenvectors for this Principal Component Analysis (ordered by their
        eigenvalue).
    -   mean The sample mean calculated from the training data.
    -   projections The projections of the training data.
    -   labels The threshold applied in the prediction. If the distance to the nearest neighbor is
        larger than the threshold, this method returns -1.
     */
    CV_WRAP static Ptr<EigenFaceRecognizer> create(int num_components = 0, double threshold = DBL_MAX);
};

class CV_EXPORTS_W FisherFaceRecognizer : public BasicFaceRecognizer
{
public:
    /**
    @param num_components The number of components (read: Fisherfaces) kept for this Linear
    Discriminant Analysis with the Fisherfaces criterion. It's useful to keep all components, that
    means the number of your classes c (read: subjects, persons you want to recognize). If you leave
    this at the default (0) or set it to a value less-equal 0 or greater (c-1), it will be set to the
    correct number (c-1) automatically.
    @param threshold The threshold applied in the prediction. If the distance to the nearest neighbor
    is larger than the threshold, this method returns -1.

    ### Notes:

    -   Training and prediction must be done on grayscale images, use cvtColor to convert between the
        color spaces.
    -   **THE FISHERFACES METHOD MAKES THE ASSUMPTION, THAT THE TRAINING AND TEST IMAGES ARE OF EQUAL
        SIZE.** (caps-lock, because I got so many mails asking for this). You have to make sure your
        input data has the correct shape, else a meaningful exception is thrown. Use resize to resize
        the images.
    -   This model does not support updating.

    ### Model internal data:

    -   num_components see FisherFaceRecognizer::create.
    -   threshold see FisherFaceRecognizer::create.
    -   eigenvalues The eigenvalues for this Linear Discriminant Analysis (ordered descending).
    -   eigenvectors The eigenvectors for this Linear Discriminant Analysis (ordered by their
        eigenvalue).
    -   mean The sample mean calculated from the training data.
    -   projections The projections of the training data.
    -   labels The labels corresponding to the projections.
     */
    CV_WRAP static Ptr<FisherFaceRecognizer> create(int num_components = 0, double threshold = DBL_MAX);
};


class CV_EXPORTS_W LBPHFaceRecognizer : public FaceRecognizer
{
public:
    /** @see setGridX */
    CV_WRAP virtual int getGridX() const = 0;
    /** @copybrief getGridX @see getGridX */
    CV_WRAP virtual void setGridX(int val) = 0;
    /** @see setGridY */
    CV_WRAP virtual int getGridY() const = 0;
    /** @copybrief getGridY @see getGridY */
    CV_WRAP virtual void setGridY(int val) = 0;
    /** @see setRadius */
    CV_WRAP virtual int getRadius() const = 0;
    /** @copybrief getRadius @see getRadius */
    CV_WRAP virtual void setRadius(int val) = 0;
    /** @see setNeighbors */
    CV_WRAP virtual int getNeighbors() const = 0;
    /** @copybrief getNeighbors @see getNeighbors */
    CV_WRAP virtual void setNeighbors(int val) = 0;
    /** @see setThreshold */
    CV_WRAP virtual double getThreshold() const CV_OVERRIDE = 0;
    /** @copybrief getThreshold @see getThreshold */
    CV_WRAP virtual void setThreshold(double val) CV_OVERRIDE = 0;
    CV_WRAP virtual std::vector<cv::Mat> getHistograms() const = 0;
    CV_WRAP virtual cv::Mat getLabels() const = 0;

    /**
    @param radius The radius used for building the Circular Local Binary Pattern. The greater the
    radius, the smoother the image but more spatial information you can get.
    @param neighbors The number of sample points to build a Circular Local Binary Pattern from. An
    appropriate value is to use `8` sample points. Keep in mind: the more sample points you include,
    the higher the computational cost.
    @param grid_x The number of cells in the horizontal direction, 8 is a common value used in
    publications. The more cells, the finer the grid, the higher the dimensionality of the resulting
    feature vector.
    @param grid_y The number of cells in the vertical direction, 8 is a common value used in
    publications. The more cells, the finer the grid, the higher the dimensionality of the resulting
    feature vector.
    @param threshold The threshold applied in the prediction. If the distance to the nearest neighbor
    is larger than the threshold, this method returns -1.

    ### Notes:

    -   The Circular Local Binary Patterns (used in training and prediction) expect the data given as
        grayscale images, use cvtColor to convert between the color spaces.
    -   This model supports updating.

    ### Model internal data:

    -   radius see LBPHFaceRecognizer::create.
    -   neighbors see LBPHFaceRecognizer::create.
    -   grid_x see LLBPHFaceRecognizer::create.
    -   grid_y see LBPHFaceRecognizer::create.
    -   threshold see LBPHFaceRecognizer::create.
    -   histograms Local Binary Patterns Histograms calculated from the given training data (empty if
        none was given).
    -   labels Labels corresponding to the calculated Local Binary Patterns Histograms.
     */
    CV_WRAP static Ptr<LBPHFaceRecognizer> create(int radius=1, int neighbors=8, int grid_x=8, int grid_y=8, double threshold = DBL_MAX);
};

//! @}

}} //namespace cv::face

#endif //__OPENCV_FACEREC_HPP__