/******************************************************************************
 * Project:  GDAL
 * Purpose:  Correlator - GDALSimpleSURF and GDALFeaturePoint classes. 
 * Author:   Andrew Migal, migal.drew@gmail.com
 *
 ******************************************************************************
 * Copyright (c) 2012, Andrew Migal
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 ****************************************************************************/

#include "gdal_simplesurf.h"

CPL_CVSID("$Id");

/************************************************************************/
/* ==================================================================== */
/*                            GDALFeaturePoint                          */
/* ==================================================================== */
/************************************************************************/

GDALFeaturePoint::GDALFeaturePoint()
{
    nX =      -1;
    nY =      -1;
    nScale =  -1;
    nRadius = -1;
    nSign =   -1;

    padfDescriptor = new double[DESC_SIZE];
}

GDALFeaturePoint::GDALFeaturePoint(const GDALFeaturePoint& fp)
{
    nX = fp.nX;
    nY = fp.nY;
    nScale = fp.nScale;
    nRadius = fp.nRadius;
    nSign = fp.nSign;

    padfDescriptor = new double[DESC_SIZE];
    for (int i = 0; i < DESC_SIZE; i++)
        padfDescriptor[i] = fp.padfDescriptor[i];
}

GDALFeaturePoint::GDALFeaturePoint(int nX, int nY,
                                   int nScale, int nRadius, int nSign)
{
    this->nX = nX;
    this->nY = nY;
    this->nScale = nScale;
    this->nRadius = nRadius;
    this->nSign = nSign;

    this->padfDescriptor = new double[DESC_SIZE];
}

GDALFeaturePoint& GDALFeaturePoint::operator=(const GDALFeaturePoint& point)
{
    if (this != &point)
    {
        nX = point.nX;
        nY = point.nY;
        nScale = point.nScale;
        nRadius = point.nRadius;
        nSign = point.nSign;

        //Free memory
        delete[] padfDescriptor;

        //Copy descriptor values
        padfDescriptor = new double[DESC_SIZE];
        for (int i = 0; i < DESC_SIZE; i++)
            padfDescriptor[i] = point.padfDescriptor[i];
    }

    return *this;
}

int  GDALFeaturePoint::GetX() { return nX; }
void GDALFeaturePoint::SetX(int nX) { this->nX = nX; }

int  GDALFeaturePoint::GetY() { return nY; }
void GDALFeaturePoint::SetY(int nY) { this->nY = nY; }

int  GDALFeaturePoint::GetScale() { return nScale; }
void GDALFeaturePoint::SetScale(int nScale) { this->nScale = nScale; }

int  GDALFeaturePoint::GetRadius() { return nRadius; }
void GDALFeaturePoint::SetRadius(int nRadius) { this->nRadius = nRadius; }

int  GDALFeaturePoint::GetSign() { return nSign; }
void GDALFeaturePoint::SetSign(int nSign) { this->nSign = nSign; }

double& GDALFeaturePoint::operator [] (int nIndex)
{
    if (nIndex < 0 || nIndex >= DESC_SIZE)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Descriptor index is out of range");
    }

    return padfDescriptor[nIndex];
}

GDALFeaturePoint::~GDALFeaturePoint() {
    delete[] padfDescriptor;
}

/************************************************************************/
/* ==================================================================== */
/*                            GDALSimpleSurf                            */
/* ==================================================================== */
/************************************************************************/

GDALSimpleSURF::GDALSimpleSURF(int nOctaveStart, int nOctaveEnd)
{
    this->octaveStart = nOctaveStart;
    this->octaveEnd = nOctaveEnd;

    // Initialize Octave map with custom range
    poOctMap = new GDALOctaveMap(octaveStart, octaveEnd);
}

CPLErr GDALSimpleSURF::ConvertRGBToLuminosity(
    GDALRasterBand *red, GDALRasterBand *green, GDALRasterBand *blue,
    int nXSize, int nYSize, double **padfImg, int nHeight, int nWidth)
{
    const double forRed = 0.21;
    const double forGreen = 0.72;
    const double forBlue = 0.07;

    if (red == NULL || green == NULL || blue == NULL)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Raster bands are not specified");
        return CE_Failure;
    }

    if (nXSize > red->GetXSize() || nYSize > red->GetYSize())
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Red band has less size than has been requested");
        return CE_Failure;
    }

    if (padfImg == NULL)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Buffer isn't specified");
        return CE_Failure;
    }

    GDALDataType eRedType = red->GetRasterDataType();
    GDALDataType eGreenType = green->GetRasterDataType();
    GDALDataType eBlueType = blue->GetRasterDataType();

    int dataRedSize = GDALGetDataTypeSize(eRedType) / 8;
    int dataGreenSize = GDALGetDataTypeSize(eGreenType) / 8;
    int dataBlueSize = GDALGetDataTypeSize(eBlueType) / 8;

    void *paRedLayer = CPLMalloc(dataRedSize * nWidth * nHeight);
    void *paGreenLayer = CPLMalloc(dataGreenSize * nWidth * nHeight);
    void *paBlueLayer = CPLMalloc(dataBlueSize * nWidth * nHeight);

    red->RasterIO(GF_Read, 0, 0, nXSize, nYSize, paRedLayer, nWidth, nHeight, eRedType, 0, 0);
    green->RasterIO(GF_Read, 0, 0, nXSize, nYSize, paGreenLayer, nWidth, nHeight, eGreenType, 0, 0);
    blue->RasterIO(GF_Read, 0, 0, nXSize, nYSize, paBlueLayer, nWidth, nHeight, eBlueType, 0, 0);

    double maxValue = 255.0;
    for (int row = 0; row < nHeight; row++)
        for (int col = 0; col < nWidth; col++)
        {
            // Get RGB values
            double dfRedVal = SRCVAL(paRedLayer, eRedType,
                                     nWidth * row + col * dataRedSize);
            double dfGreenVal = SRCVAL(paGreenLayer, eGreenType,
                                       nWidth * row + col * dataGreenSize);
            double dfBlueVal = SRCVAL(paBlueLayer, eBlueType,
                                      nWidth * row + col * dataBlueSize);
            // Compute luminosity value
            padfImg[row][col] = (
                dfRedVal * forRed +
                dfGreenVal * forGreen +
                dfBlueVal * forBlue) / maxValue;
        }

    CPLFree(paRedLayer);
    CPLFree(paGreenLayer);
    CPLFree(paBlueLayer);

    return CE_None;
}

std::vector<GDALFeaturePoint>*
GDALSimpleSURF::ExtractFeaturePoints(GDALIntegralImage *poImg,
                                     double dfThreshold)
{
    std::vector<GDALFeaturePoint>* poCollection = 
        new std::vector<GDALFeaturePoint>();

    //Calc Hessian values for layers
    poOctMap->ComputeMap(poImg);

    //Search for exremum points
    for (int oct = octaveStart; oct <= octaveEnd; oct++)
    {
        for (int k = 0; k < GDALOctaveMap::INTERVALS - 2; k++)
        {
            GDALOctaveLayer *bot = poOctMap->pMap[oct - 1][k];
            GDALOctaveLayer *mid = poOctMap->pMap[oct - 1][k + 1];
            GDALOctaveLayer *top = poOctMap->pMap[oct - 1][k + 2];

            for (int i = 0; i < mid->height; i++)
            {
                for (int j = 0; j < mid->width; j++)
                {
                    if (poOctMap->PointIsExtremum(i, j, bot, mid, top, dfThreshold))
                    {
                        GDALFeaturePoint oFP(j, i, mid->scale,
                                             mid->radius, mid->signs[i][j]);
                        SetDescriptor(&oFP, poImg);
                        poCollection->push_back(oFP);
                    }
                }
            }
        }
    }
    
    return poCollection;
}


double GDALSimpleSURF::GetEuclideanDistance(
    GDALFeaturePoint &firstPoint, GDALFeaturePoint &secondPoint)
{
    double sum = 0;

    for (int i = 0; i < GDALFeaturePoint::DESC_SIZE; i++)
        sum += (firstPoint[i] - secondPoint[i]) * (firstPoint[i] - secondPoint[i]);

    return sqrt(sum);
}

void GDALSimpleSURF::NormalizeDistances(std::list<MatchedPointPairInfo> *poList)
{
    double max = 0;

    std::list<MatchedPointPairInfo>::iterator i;
    for (i = poList->begin(); i != poList->end(); i++)
        if ((*i).euclideanDist > max)
            max = (*i).euclideanDist;

    if (max != 0)
    {
        for (i = poList->begin(); i != poList->end(); i++)
            (*i).euclideanDist /= max;
    }
}

void GDALSimpleSURF::SetDescriptor(
    GDALFeaturePoint *poPoint, GDALIntegralImage *poImg)
{
    // Affects to the descriptor area
    const int haarScale = 20;

    // Side of the Haar wavelet
    int haarFilterSize = 2 * poPoint->GetScale();

    // Length of the side of the descriptor area
    int descSide = haarScale * poPoint->GetScale();

    // Side of the quadrant in 4x4 grid
    int quadStep = descSide / 4;

    // Side of the sub-quadrant in 5x5 regular grid of quadrant
    int subQuadStep = quadStep / 5;

    int leftTop_row = poPoint->GetY() - (descSide / 2);
    int leftTop_col = poPoint->GetX() - (descSide / 2);

    int count = 0;

    for (int r = leftTop_row; r < leftTop_row + descSide; r += quadStep)
        for (int c = leftTop_col; c < leftTop_col + descSide; c += quadStep)
        {
            double dx = 0;
            double dy = 0;
            double abs_dx = 0;
            double abs_dy = 0;

            for (int sub_r = r; sub_r < r + quadStep; sub_r += subQuadStep)
                for (int sub_c = c; sub_c < c + quadStep; sub_c += subQuadStep)
                {
                    // Approximate center of sub quadrant
                    int cntr_r = sub_r + subQuadStep / 2;
                    int cntr_c = sub_c + subQuadStep / 2;

                    // Left top point for Haar wavelet computation
                    int cur_r = cntr_r - haarFilterSize / 2;
                    int cur_c = cntr_c - haarFilterSize / 2;

                    // Gradients
                    double cur_dx = poImg->HaarWavelet_X(cur_r, cur_c, haarFilterSize);
                    double cur_dy = poImg->HaarWavelet_Y(cur_r, cur_c, haarFilterSize);

                    dx += cur_dx;
                    dy += cur_dy;
                    abs_dx += fabs(cur_dx);
                    abs_dy += fabs(cur_dy);
                }

            // Fills point's descriptor
            (*poPoint)[count++] = dx;
            (*poPoint)[count++] = dy;
            (*poPoint)[count++] = abs_dx;
            (*poPoint)[count++] = abs_dy;
        }
}

/**
 * Find corresponding points (equal points in two collections).
 *
 * @param poMatched Resulting collection for matched points
 * @param poFirstCollection Points on the first image
 * @param poSecondCollection Points on the second image
 * @param dfThreshold Value from 0 to 1. Threshold affects to number of
 * matched points. If threshold is higher, amount of corresponding
 * points is larger, and vice versa
 *
 * @note Typical threshold's value is 0,1. BUT it's a very approximate guide.
 * It can be 0,001 or even 1. This threshold provides direct adjustment
 * of point matching.
 * NOTICE that if threshold is lower, matches are more robust and correct, but number of
 * matched points is smaller. Therefore if algorithm performs many false
 * detections and produces bad results, reduce threshold.
 * Otherwise, if algorithm finds nothing, increase threshold.
 *
 * @return CE_None or CE_Failure if error occurs.
 */

CPLErr GDALSimpleSURF::MatchFeaturePoints(
    std::vector<GDALFeaturePoint*> *poMatchPairs,
    std::vector<GDALFeaturePoint> *poFirstCollect,
    std::vector<GDALFeaturePoint> *poSecondCollect,
    double dfThreshold)
{
/* -------------------------------------------------------------------- */
/*      Validate parameters.                                            */
/* -------------------------------------------------------------------- */
    if (poMatchPairs == NULL)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Matched points colection isn't specified");
        return CE_Failure;
    }

    if (poFirstCollect == NULL || poSecondCollect == NULL)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Feature point collections are not specified");
        return CE_Failure;
    }

/* ==================================================================== */
/*      Matching algorithm.                                             */
/* ==================================================================== */
    // Affects to false matching pruning
    const double ratioThreshold = 0.8;

    int len_1 = poFirstCollect->size();
    int len_2 = poSecondCollect->size();

    int minLength = (len_1 < len_2) ? len_1 : len_2;

    // Temporary pointers. Used to swap collections
    std::vector<GDALFeaturePoint> *p_1;
    std::vector<GDALFeaturePoint> *p_2;

    bool isSwap = false;

    // Assign p_1 - collection with minimal number of points
    if (minLength == len_2)
    {
        p_1 = poSecondCollect;
        p_2 = poFirstCollect;

        int tmp = 0;
        tmp = len_1;
        len_1 = len_2;
        len_2 = tmp;
        isSwap = true;
    }
    else
    {
        // Assignment 'as is'
        p_1 = poFirstCollect;
        p_2 = poSecondCollect;
        isSwap = false;
    }

    // Stores matched point indexes and
    // their euclidean distances
    std::list<MatchedPointPairInfo> *poPairInfoList =
        new std::list<MatchedPointPairInfo>();

    // Flags that points in the 2nd collection are matched or not
    bool *alreadyMatched = new bool[len_2];
    for (int i = 0; i < len_2; i++)
        alreadyMatched[i] = false;

    for (int i = 0; i < len_1; i++)
    {
        // Distance to the nearest point
        double bestDist = -1;
        // Index of the nearest point in p_2 collection
        int bestIndex = -1;

        // Distance to the 2nd nearest point
        double bestDist_2 = -1;

        // Find the nearest and 2nd nearest points
        for (int j = 0; j < len_2; j++)
            if (!alreadyMatched[j])
                if (p_1->at(i).GetSign() ==
                    p_2->at(j).GetSign())
                {
                    // Get distance between two feature points
                    double curDist = GetEuclideanDistance(
                        p_1->at(i), p_2->at(j));

                    if (bestDist == -1)
                    {
                        bestDist = curDist;
                        bestIndex = j;
                    }
                    else
                    {
                        if (curDist < bestDist)
                        {
                            bestDist = curDist;
                            bestIndex = j;
                        }
                    }

                    // Findes the 2nd nearest point
                    if (bestDist_2 < 0)
                        bestDist_2 = curDist;
                    else
                        if (curDist > bestDist && curDist < bestDist_2)
                            bestDist_2 = curDist;
                }
/* -------------------------------------------------------------------- */
/*	    False matching pruning.                                         */
/* If ratio bestDist to bestDist_2 greater than 0.8 =>                  */
/* 		consider as false detection.                                    */
/* Otherwise, add points as matched pair.                               */
/*----------------------------------------------------------------------*/
        if (bestDist_2 > 0 && bestDist >= 0)
            if (bestDist / bestDist_2 < ratioThreshold)
            {
                MatchedPointPairInfo info(i, bestIndex, bestDist);
                poPairInfoList->push_back(info);
                alreadyMatched[bestIndex] = true;
            }
    }


/* -------------------------------------------------------------------- */
/*      Pruning based on the provided threshold                         */
/* -------------------------------------------------------------------- */

    NormalizeDistances(poPairInfoList);

    std::list<MatchedPointPairInfo>::const_iterator iter;
    for (iter = poPairInfoList->begin(); iter != poPairInfoList->end(); iter++)
    {
        if ((*iter).euclideanDist <= dfThreshold)
        {
            int i_1 = (*iter).ind_1;
            int i_2 = (*iter).ind_2;

            // Add copies into MatchedCollection
            if(!isSwap)
            {
                poMatchPairs->push_back( &(p_1->at(i_1)) );
                poMatchPairs->push_back( &(p_2->at(i_2)) );
            }
            else
            {
                poMatchPairs->push_back( &(p_2->at(i_2)) );
                poMatchPairs->push_back( &(p_1->at(i_1)) );
            }
        }
    }

    // Clean up
    delete[] alreadyMatched;

    return CE_None;
}

GDALSimpleSURF::~GDALSimpleSURF()
{
    delete poOctMap;
}