opencv/modules/photo/src/contrast_preserve.hpp

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#include "precomp.hpp"
#include "opencv2/photo.hpp"
#include "math.h"
#include <vector>
#include <limits>

using namespace std;
using namespace cv;

class Decolor
{
    private:
        Mat kernelx;
        Mat kernely;
        int order;

    public:
        float sigma;
        void init();
        vector<double> product(vector < vector<int> > &comb, vector <double> &initRGB);
        double energyCalcu(vector <double> &Cg, vector < vector <double> > &polyGrad, vector <double> &wei);
        void singleChannelGradx(const Mat &img, Mat& dest);
        void singleChannelGrady(const Mat &img, Mat& dest);
        void gradvector(const Mat &img, vector <double> &grad);
        void colorGrad(Mat img, vector <double> &Cg);
        void add_vector(vector < vector <int> > &comb, int &idx, int r,int g,int b);
        void add_to_vector_poly(vector < vector <double> > &polyGrad, vector <double> &curGrad, int &idx1);
        void weak_order(Mat img, vector <double> &alf);
        void grad_system(Mat img, vector < vector < double > > &polyGrad,
                vector < double > &Cg, vector < vector <int> >& comb);
        void wei_update_matrix(vector < vector <double> > &poly, vector <double> &Cg, Mat &X);
        void wei_inti(vector < vector <int> > &comb, vector <double> &wei);
        void grayImContruct(vector <double> &wei, Mat img, Mat &Gray);
};

int round_num(double a);

int round_num(double a)
{
    return int(a + 0.5);
}

double Decolor::energyCalcu(vector <double> &Cg, vector < vector <double> > &polyGrad, vector <double> &wei)
{
    vector <double> energy;
    vector <double> temp;
    vector <double> temp1;

    double val = 0.0;
    for(unsigned int i=0;i< polyGrad[0].size();i++)
    {
        val = 0.0;
        for(unsigned int j =0;j<polyGrad.size();j++)
            val = val + (polyGrad[j][i] * wei[j]);
        temp.push_back(val - Cg[i]);
        temp1.push_back(val + Cg[i]);
    }

    for(unsigned int i=0;i<polyGrad[0].size();i++)
        energy.push_back(-1.0*log(exp(-1.0*pow(temp[i],2)/sigma) + exp(-1.0*pow(temp1[i],2)/sigma)));

    double sum = 0.0;
    for(unsigned int i=0;i<polyGrad[0].size();i++)
        sum +=energy[i];

    return (sum/polyGrad[0].size());

}

void Decolor::init()
{
    kernelx = Mat(1,2, CV_32FC1);
    kernely = Mat(2,1, CV_32FC1);
    kernelx.at<float>(0,0)=1.0;
    kernelx.at<float>(0,1)=-1.0;
    kernely.at<float>(0,0)=1.0;
    kernely.at<float>(1,0)=-1.0;
    order = 2;
    sigma = 0.02f;
}

vector<double> Decolor::product(vector < vector<int> > &comb, vector <double> &initRGB)
{
    vector <double> res;
    double dp;
    for (unsigned int i=0;i<comb.size();i++)
    {
        dp = 0.0;
        for(int j=0;j<3;j++)
            dp = dp + (comb[i][j] * initRGB[j]);
        res.push_back(dp);
    }
    return res;
}

void Decolor::singleChannelGradx(const Mat &img, Mat& dest)
{
    int w=img.size().width;
    int h=img.size().height;
    Point anchor(kernelx.cols - kernelx.cols/2 - 1, kernelx.rows - kernelx.rows/2 - 1);
    filter2D(img, dest, -1, kernelx, anchor, 0.0, BORDER_CONSTANT);
    for(int i=0;i<h;i++)
        dest.at<float>(i,w-1)=0.0;
}

void Decolor::singleChannelGrady(const Mat &img, Mat& dest)
{
    int w=img.size().width;
    int h=img.size().height;
    Point anchor(kernely.cols - kernely.cols/2 - 1, kernely.rows - kernely.rows/2 - 1);
    filter2D(img, dest, -1, kernely, anchor, 0.0, BORDER_CONSTANT);
    for(int j=0;j<w;j++)
        dest.at<float>(h-1,j)=0.0;
}

void Decolor::gradvector(const Mat &img, vector <double> &grad)
{
    Mat dest= Mat(img.size().height,img.size().width, CV_32FC1);
    Mat dest1= Mat(img.size().height,img.size().width, CV_32FC1);
    singleChannelGradx(img,dest);
    singleChannelGrady(img,dest1);

    Mat d_trans=dest.t();
    Mat d1_trans=dest1.t();

    int height = d_trans.size().height;
    int width = d_trans.size().width;

    for(int i=0;i<height;i++)
        for(int j=0;j<width;j++)
            grad.push_back(d_trans.at<float>(i,j));

    for(int i=0;i<height;i++)
        for(int j=0;j<width;j++)
            grad.push_back(d1_trans.at<float>(i,j));
    dest.release();
    dest1.release();
}

void Decolor::colorGrad(Mat img, vector <double> &Cg)
{

    Mat lab = Mat(img.size(),CV_32FC3);

    cvtColor(img,lab,COLOR_BGR2Lab);

    vector <Mat> lab_channel;
    split(lab,lab_channel);

    vector <double> ImL;
    vector <double> Ima;
    vector <double> Imb;

    gradvector(lab_channel[0],ImL);
    gradvector(lab_channel[1],Ima);
    gradvector(lab_channel[2],Imb);

    double res =0.0;
    for(unsigned int i=0;i<ImL.size();i++)
    {
        res=sqrt(pow(ImL[i],2) + pow(Ima[i],2) + pow(Imb[i],2))/100;
        Cg.push_back(res);
    }

    ImL.clear();
    Ima.clear();
    Imb.clear();
}

void Decolor::add_vector(vector < vector <int> > &comb, int &idx, int r,int g,int b)
{
    comb.push_back( vector <int>() );
    comb.at(idx).push_back( r );
    comb.at(idx).push_back( g );
    comb.at(idx).push_back( b );
    idx++;
}

void Decolor::add_to_vector_poly(vector < vector <double> > &polyGrad, vector <double> &curGrad, int &idx1)
{
    polyGrad.push_back( vector <double>() );
    for(unsigned int i=0;i<curGrad.size();i++)
        polyGrad.at(idx1).push_back(curGrad[i]);
    idx1++;
}

void Decolor::weak_order(Mat img, vector <double> &alf)
{
    int h = img.size().height;
    int w = img.size().width;
    double sizefactor;
    if((h + w) > 800)
    {
        sizefactor = (double)800/(h+w);
        resize(img,img,Size(round_num(h*sizefactor),round_num(w*sizefactor)));
    }

    Mat curIm = Mat(img.size(),CV_32FC1);
    vector <Mat> rgb_channel;
    split(img,rgb_channel);

    vector <double> Rg, Gg, Bg;
    vector <double> t1, t2, t3;
    vector <double> tmp1, tmp2, tmp3;

    gradvector(rgb_channel[2],Rg);
    gradvector(rgb_channel[1],Gg);
    gradvector(rgb_channel[0],Bg);

    double level = .05;

    for(unsigned int i=0;i<Rg.size();i++)
    {
        if(Rg[i] > level)
            t1.push_back(1.0);
        else
            t1.push_back(0.0);

        if(Gg[i] > level)
            t2.push_back(1.0);
        else
            t2.push_back(0.0);

        if(Bg[i] > level)
            t3.push_back(1.0);
        else
            t3.push_back(0.0);

        if(Rg[i] < -1.0*level)
            tmp1.push_back(1.0);
        else
            tmp1.push_back(0.0);

        if(Gg[i] < -1.0*level)
            tmp2.push_back(1.0);
        else
            tmp2.push_back(0.0);

        if(Bg[i] < -1.0*level)
            tmp3.push_back(1.0);
        else
            tmp3.push_back(0.0);
    }
    for(unsigned int i =0 ;i < Rg.size();i++)
        alf.push_back(t1[i] * t2[i] * t3[i]);

    for(unsigned int i =0 ;i < Rg.size();i++)
        alf[i] -= tmp1[i] * tmp2[i] * tmp3[i];

    double sum =0.0;
    for(unsigned int i=0;i<alf.size();i++)
        sum += abs(alf[i]);

    sum = (double)100*sum/alf.size();

    Rg.clear(); Gg.clear(); Bg.clear();
    t1.clear(); t2.clear(); t3.clear();
    tmp1.clear(); tmp2.clear(); tmp3.clear();
}

void Decolor::grad_system(Mat img, vector < vector < double > > &polyGrad,
        vector < double > &Cg, vector < vector <int> >& comb)
{
    int h = img.size().height;
    int w = img.size().width;

    double sizefactor;
    if((h + w) > 800)
    {
        sizefactor = (double)800/(h+w);
        resize(img,img,Size(round_num(h*sizefactor),round_num(w*sizefactor)));
    }

    h = img.size().height;
    w = img.size().width;
    colorGrad(img,Cg);

    Mat curIm = Mat(img.size(),CV_32FC1);
    vector <Mat> rgb_channel;
    split(img,rgb_channel);

    int idx = 0, idx1 = 0;
    for(int r=0 ;r <=order; r++)
        for(int g=0; g<=order;g++)
            for(int b =0; b <=order;b++)
            {
                if((r+g+b)<=order && (r+g+b) > 0)
                {
                    add_vector(comb,idx,r,g,b);
                    for(int i = 0;i<h;i++)
                        for(int j=0;j<w;j++)
                            curIm.at<float>(i,j)=
                                pow(rgb_channel[2].at<float>(i,j),r)*pow(rgb_channel[1].at<float>(i,j),g)*
                                pow(rgb_channel[0].at<float>(i,j),b);
                    vector <double> curGrad;
                    gradvector(curIm,curGrad);
                    add_to_vector_poly(polyGrad,curGrad,idx1);
                }
            }
}

void Decolor::wei_update_matrix(vector < vector <double> > &poly, vector <double> &Cg, Mat &X)
{
    int size = static_cast<int>(poly.size()), size0 = static_cast<int>(poly[0].size());
    Mat P = Mat(size, size0, CV_32FC1);
    Mat A = Mat(size, size, CV_32FC1);

    for (int i = 0; i < size; i++)
        for (int j = 0; j < size0;j++)
            P.at<float>(i,j) = (float) poly[i][j];

    Mat P_trans = P.t();
    Mat B = Mat(size, size0, CV_32FC1);
    for(int i =0;i < size;i++)
    {
        for(int j = 0, end = (int)Cg.size(); j < end;j++)
            B.at<float>(i,j) = (float) (poly[i][j] * Cg[j]);
    }

    A = P*P_trans;
    solve(A, B, X, DECOMP_NORMAL);

}

void Decolor::wei_inti(vector < vector <int> > &comb, vector <double> &wei)
{
    vector <double> initRGB;

    initRGB.push_back( .33 );
    initRGB.push_back( .33 );
    initRGB.push_back( .33 );
    wei = product(comb,initRGB);

    vector <int> sum;

    for(unsigned int i=0;i<comb.size();i++)
        sum.push_back(comb[i][0] + comb[i][1] + comb[i][2]);

    for(unsigned int i=0;i<sum.size();i++)
    {
        if(sum[i] == 1)
            wei[i] = wei[i] * double(1);
        else
            wei[i] = wei[i] * double(0);
    }

    initRGB.clear();
    sum.clear();

}

void Decolor::grayImContruct(vector <double> &wei, Mat img, Mat &Gray)
{
    int h=img.size().height;
    int w=img.size().width;

    vector <Mat> rgb_channel;
    split(img,rgb_channel);

    int kk =0;

    for(int r =0;r<=order;r++)
        for(int g=0;g<=order;g++)
            for(int b=0;b<=order;b++)
                if((r + g + b) <=order && (r+g+b) > 0)
                {
                    for(int i = 0;i<h;i++)
                        for(int j=0;j<w;j++)
                            Gray.at<float>(i,j)=Gray.at<float>(i,j) +
                                (float) wei[kk]*pow(rgb_channel[2].at<float>(i,j),r)*pow(rgb_channel[1].at<float>(i,j),g)*
                                pow(rgb_channel[0].at<float>(i,j),b);

                    kk=kk+1;
                }

    float minval = FLT_MAX;
    float maxval = -FLT_MAX;

    for(int i=0;i<h;i++)
        for(int j =0;j<w;j++)
       {
            if(Gray.at<float>(i,j) < minval)
                minval = Gray.at<float>(i,j);

            if(Gray.at<float>(i,j) > maxval)
                maxval = Gray.at<float>(i,j);
        }

    Gray -= minval;
    Gray /= maxval - minval;
}