/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * Copyright 2012 The MITRE Corporation                                      *
 *                                                                           *
 * Licensed under the Apache License, Version 2.0 (the "License");           *
 * you may not use this file except in compliance with the License.          *
 * You may obtain a copy of the License at                                   *
 *                                                                           *
 *     http://www.apache.org/licenses/LICENSE-2.0                            *
 *                                                                           *
 * Unless required by applicable law or agreed to in writing, software       *
 * distributed under the License is distributed on an "AS IS" BASIS,         *
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  *
 * See the License for the specific language governing permissions and       *
 * limitations under the License.                                            *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

#include <openbr_plugin.h>

#include "core/opencvutils.h"

using namespace cv;

namespace br
{

/*!
 * \ingroup transforms
 * \brief Approximate floats as uchar.
 * \author Josh Klontz \cite jklontz
 */
class QuantizeTransform : public Transform
{
    Q_OBJECT
    Q_PROPERTY(float a READ get_a WRITE set_a RESET reset_a)
    Q_PROPERTY(float b READ get_b WRITE set_b RESET reset_b)
    BR_PROPERTY(float, a, 1)
    BR_PROPERTY(float, b, 0)

    void train(const TemplateList &data)
    {
        double minVal, maxVal;
        minMaxLoc(OpenCVUtils::toMat(data.data()), &minVal, &maxVal);
        a = 255.0/(maxVal-minVal);
        b = -a*minVal;
    }

    void project(const Template &src, Template &dst) const
    {
        src.m().convertTo(dst, CV_8U, a, b);
    }
};

BR_REGISTER(Transform, QuantizeTransform)

/*!
 * \ingroup transforms
 * \brief Approximate floats as signed bit.
 * \author Josh Klontz \cite jklontz
 */
class BinarizeTransform : public UntrainableTransform
{
    Q_OBJECT

    void project(const Template &src, Template &dst) const
    {
        const Mat &m = src;
        if ((m.cols % 8 != 0) || (m.type() != CV_32FC1))
            qFatal("Expected CV_32FC1 matrix with a multiple of 8 columns.");
        Mat n(m.rows, m.cols/8, CV_8UC1);
        for (int i=0; i<m.rows; i++)
            for (int j=0; j<m.cols-7; j+=8)
                n.at<uchar>(i,j) = ((m.at<float>(i,j+0) > 0) << 0) +
                                   ((m.at<float>(i,j+1) > 0) << 1) +
                                   ((m.at<float>(i,j+2) > 0) << 2) +
                                   ((m.at<float>(i,j+3) > 0) << 3) +
                                   ((m.at<float>(i,j+4) > 0) << 4) +
                                   ((m.at<float>(i,j+5) > 0) << 5) +
                                   ((m.at<float>(i,j+6) > 0) << 6) +
                                   ((m.at<float>(i,j+7) > 0) << 7);
        dst = n;
    }
};

BR_REGISTER(Transform, BinarizeTransform)

/*!
 * \ingroup transforms
 * \brief Compress two uchar into one uchar.
 * \author Josh Klontz \cite jklontz
 */
class PackTransform : public UntrainableTransform
{
    Q_OBJECT

    void project(const Template &src, Template &dst) const
    {
        const Mat &m = src;
        if ((m.cols % 2 != 0) || (m.type() != CV_8UC1))
            qFatal("Invalid template format.");

        Mat n(m.rows, m.cols/2, CV_8UC1);
        for (int i=0; i<m.rows; i++)
            for (int j=0; j<m.cols/2; j++)
                n.at<uchar>(i,j) = ((m.at<uchar>(i,2*j+0) >> 4) << 4) +
                                   ((m.at<uchar>(i,2*j+1) >> 4) << 0);
        dst = n;
    }
};

BR_REGISTER(Transform, PackTransform)

/*!
 * \ingroup distances
 * \brief Product quantization distance.
 * \author Josh Klontz \cite jklontz
 */
class ProductQuantizationDistance : public Distance
{
    Q_OBJECT
    friend class ProductQuantizationTransform;
    static QList<Mat> luts;

    float compare(const Template &a, const Template &b) const
    {
        float distance = 0;
        for (int i=0; i<a.m().cols; i++)
            distance += pow(luts[i].at<float>(a.m().at<uchar>(0,i), b.m().at<uchar>(0,i)),2);
        return sqrt(distance);
    }
};

QList<Mat> ProductQuantizationDistance::luts;

BR_REGISTER(Distance, ProductQuantizationDistance)

/*!
 * \ingroup transforms
 * \brief Product quantization \cite jegou11
 * \author Josh Klonyz \cite jklontz
 */
class ProductQuantizationTransform : public Transform
{
    Q_OBJECT
    static int counter;
    int index;
    Mat centers, lut;

public:
    ProductQuantizationTransform()
    {
        index = counter++;
        ProductQuantizationDistance::luts.append(Mat());
    }

private:
    void train(const TemplateList &src)
    {
        Mat data = OpenCVUtils::toMat(src.data());
        Mat labels;
        kmeans(data, 256, labels, TermCriteria(TermCriteria::MAX_ITER, 10, 0), 3, KMEANS_PP_CENTERS, centers);

        lut = Mat(256, 256, CV_32FC1);
        for (int i=0; i<256; i++)
            for (int j=0; j<256; j++)
                lut.at<float>(i,j) = norm(centers.row(i), centers.row(j), NORM_L2);
        ProductQuantizationDistance::luts[index] = lut;
    }

    void project(const Template &src, Template &dst) const
    {
        uchar bestIndex = -1;
        double bestDistance = std::numeric_limits<double>::max();
        for (uchar i=0; i<256; i++) {
            double distance = norm(src, centers.row(i), NORM_L2);
            if (distance < bestDistance) {
                bestDistance = distance;
                bestIndex = i;
            }
        }
        assert(bestIndex != -1);
        dst = Mat(1, 1, CV_8UC1);
        dst.m().at<uchar>(0,0) = bestIndex;
    }

    void store(QDataStream &stream) const
    {
        stream << centers << lut;
    }

    void load(QDataStream &stream)
    {
        stream >> centers >> lut;
        ProductQuantizationDistance::luts[index] = lut;
    }
};

int ProductQuantizationTransform::counter = 0;

BR_REGISTER(Transform, ProductQuantizationTransform)

} // namespace br

#include "quantize.moc"