diff --git a/modules/photo/include/opencv2/photo.hpp b/modules/photo/include/opencv2/photo.hpp
index e656b93e8a..6f5868dd4c 100644
--- a/modules/photo/include/opencv2/photo.hpp
+++ b/modules/photo/include/opencv2/photo.hpp
@@ -288,7 +288,7 @@ public:
 
 CV_EXPORTS_W Ptr<MergeRobertson> createMergeRobertson();
 
-CV_EXPORTS_W void decolor(InputArray src, OutputArray grayscale, OutputArray color_boost);
+CV_EXPORTS_W void decolor(InputArray src, OutputArray grayscale);
 
 } // cv
 
diff --git a/modules/photo/src/contrast_preserve.cpp b/modules/photo/src/contrast_preserve.cpp
index 271afb5e7e..6d4a2d1313 100644
--- a/modules/photo/src/contrast_preserve.cpp
+++ b/modules/photo/src/contrast_preserve.cpp
@@ -5,72 +5,162 @@
 #include <vector>
 #include <limits>
 #include <iostream>
-
 #include "contrast_preserve.hpp"
 
 using namespace std;
 using namespace cv;
-int rounding(double);
+
+int rounding(double a);
 
 int rounding(double a)
 {
-        return int(a + 0.5);
+	return int(a + 0.5);
 }
 
-void cv::decolor(InputArray _src, OutputArray _gray, OutputArray _boost)
+void cv::decolor(InputArray _src, OutputArray _dst)
 {
-        Mat I = _src.getMat();
-        _gray.create(I.size(), CV_8UC1);
-        Mat dst = _gray.getMat();
+	Mat I = _src.getMat();
+    _dst.create(I.size(), CV_8UC1);
+    Mat dst = _dst.getMat();
 
-        _boost.create(I.size(), CV_8UC3);
-        Mat color_boost = _boost.getMat();
+    if(!I.data )      
+	{
+		cout <<  "Could not open or find the image" << endl ;
+		return;
+	}
+	if(I.channels() !=3)
+	{
+		cout << "Input Color Image" << endl;
+		return;
+	}
 
-        if(!I.data )
-        {
-                cout <<  "Could not open or find the image" << endl ;
-                return;
-        }
-        if(I.channels() !=3)
-        {
-                cout << "Input Color Image" << endl;
-                return;
-        }
+	float sigma = .02;
+	int maxIter = 8;
+	int iterCount = 0;
 
-        float sigma = .02;
-        int maxIter = 8;
-        int iterCount = 0;
+	int h = I.size().height;
+	int w = I.size().width;
 
-        int h = I.size().height;
-        int w = I.size().width;
+	Decolor obj;
 
-        Mat img;
-        Decolor obj;
+	Mat img;
+	
+	double sizefactor;
 
-        double sizefactor;
+	if((h + w) > 900)
+	{
+		sizefactor = (double)900/(h+w);
+		resize(I,I,Size(rounding(h*sizefactor),rounding(w*sizefactor)));
+		img = Mat(I.size(),CV_32FC3);
+		I.convertTo(img,CV_32FC3,1.0/255.0);
+	}
+	else
+	{
+		img = Mat(I.size(),CV_32FC3);
+		I.convertTo(img,CV_32FC3,1.0/255.0);
+	}
 
-        if((h + w) > 900)
-        {
-                sizefactor = (double)900/(h+w);
-                resize(I,I,Size(rounding(h*sizefactor),rounding(w*sizefactor)));
-                img = Mat(I.size(),CV_32FC3);
-                I.convertTo(img,CV_32FC3,1.0/255.0);
-        }
-        else
-        {
-                img = Mat(I.size(),CV_32FC3);
-                I.convertTo(img,CV_32FC3,1.0/255.0);
-        }
+	obj.init();
 
-        obj.init();
+	vector <double> Cg;
+	vector < vector <double> > polyGrad;
+	vector < vector <double> > bc;
+	vector < vector < int > > comb;
 
-        vector <double> Cg;
-        vector < vector <double> > polyGrad;
-        vector < vector <double> > bc;
-        vector < vector < int > > comb;
+	vector <double> alf;
 
-        vector <double> alf;
+	obj.grad_system(img,polyGrad,Cg,comb);
+	obj.weak_order(img,alf);
+
+	Mat Mt = Mat(polyGrad.size(),polyGrad[0].size(), CV_32FC1);
+	obj.wei_update_matrix(polyGrad,Cg,Mt);
+
+	vector <double> wei;
+	obj.wei_inti(comb,wei);
+
+	//////////////////////////////// main loop starting ////////////////////////////////////////
+
+	while (iterCount < maxIter)
+	{
+		iterCount +=1;
+
+		vector <double> G_pos;
+		vector <double> G_neg;
+
+		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]);
+		}
+
+		double ans = 0.0;
+		double ans1 = 0.0;
+		for(unsigned int i =0;i<alf.size();i++)
+		{
+			ans = ((1 + alf[i])/2) * exp((-1.0 * 0.5 * pow(temp[i],2))/pow(sigma,2));
+			ans1 =((1 - alf[i])/2) * exp((-1.0 * 0.5 * pow(temp1[i],2))/pow(sigma,2));
+			G_pos.push_back(ans);
+			G_neg.push_back(ans1);
+		}
+
+		vector <double> EXPsum;
+		vector <double> EXPterm;
+
+		for(unsigned int i = 0;i<G_pos.size();i++)
+			EXPsum.push_back(G_pos[i]+G_neg[i]);
 
 
+		vector <double> temp2;
+
+		for(unsigned int i=0;i<EXPsum.size();i++)
+		{
+			if(EXPsum[i] == 0)
+				temp2.push_back(1.0);
+			else
+				temp2.push_back(0.0);
+		}
+
+		for(unsigned int i =0; i < G_pos.size();i++)
+			EXPterm.push_back((G_pos[i] - G_neg[i])/(EXPsum[i] + temp2[i]));
+
+		
+		double val1 = 0.0;
+		vector <double> wei1;
+
+		for(unsigned int i=0;i< polyGrad.size();i++)
+		{
+			val1 = 0.0;
+			for(unsigned int j =0;j<polyGrad[0].size();j++)
+			{
+				val1 = val1 + (Mt.at<float>(i,j) * EXPterm[j]);
+			}
+			wei1.push_back(val1);
+		}
+
+		for(unsigned int i =0;i<wei.size();i++)
+			wei[i] = wei1[i];
+
+		G_pos.clear();
+		G_neg.clear();
+		temp.clear();
+		temp1.clear();
+		EXPsum.clear();
+		EXPterm.clear();
+		temp2.clear();
+		wei1.clear();
+	}
+
+	Mat Gray = Mat::zeros(img.size(),CV_32FC1);
+	obj.grayImContruct(wei, img, Gray);
+
+	Gray.convertTo(dst,CV_8UC1,255);
+
+	
 }
-
diff --git a/modules/photo/src/contrast_preserve.hpp b/modules/photo/src/contrast_preserve.hpp
index 5c6cd50cf9..440427fa28 100644
--- a/modules/photo/src/contrast_preserve.hpp
+++ b/modules/photo/src/contrast_preserve.hpp
@@ -10,22 +10,411 @@ using namespace cv;
 
 class Decolor
 {
-        public:
+        private:
                 Mat kernel;
                 Mat kernel1;
                 int order;
+        
+        public:
                 void init();
+                vector<double> product(vector < vector<int> > &comb, vector <double> &initRGB);
+                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 r,int g,int b);
+                void add_to_vector_poly(vector < vector <double> > &polyGrad, vector <double> &curGrad);
+                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);
 };
 
 void Decolor::init()
 {
-        kernel = Mat(1,2, CV_32FC1);
-        kernel1 = Mat(2,1, CV_32FC1);
-        kernel.at<float>(0,0)=1.0;
-        kernel.at<float>(0,1)=-1.0;
-        kernel1.at<float>(0,0)=1.0;
-        kernel1.at<float>(1,0)=-1.0;
-        order = 2;
+	kernel = Mat(1,2, CV_32FC1);
+	kernel1 = Mat(2,1, CV_32FC1);
+	kernel.at<float>(0,0)=1.0;
+	kernel.at<float>(0,1)=-1.0;
+	kernel1.at<float>(0,0)=1.0;
+	kernel1.at<float>(1,0)=-1.0;
+	order = 2;
 
 }
+
+vector<double> Decolor::product(vector < vector<int> > &comb, vector <double> &initRGB)
+{
+	vector <double> res;
+	float dp;
+	for (unsigned int i=0;i<comb.size();i++)
+	{
+		dp = 0.0f;
+		for(int j=0;j<3;j++)
+			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(kernel.cols - kernel.cols/2 - 1, kernel.rows - kernel.rows/2 - 1);
+	filter2D(img, dest, -1, kernel, 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(kernel1.cols - kernel1.cols/2 - 1, kernel1.rows - kernel1.rows/2 - 1);
+	filter2D(img, dest, -1, kernel1, 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);
+	Mat l_channel = Mat(img.size(),CV_32FC1);
+	Mat a_channel = Mat(img.size(),CV_32FC1);
+	Mat b_channel = Mat(img.size(),CV_32FC1);
+
+	cvtColor(img,lab,COLOR_BGR2Lab);
+	for(int i=0;i<img.size().height;i++)
+		for(int j=0;j<img.size().width;j++)
+		{
+			l_channel.at<float>(i,j) = lab.at<float>(i,j*3+0);
+			a_channel.at<float>(i,j) = lab.at<float>(i,j*3+1);
+			b_channel.at<float>(i,j) = lab.at<float>(i,j*3+2);
+		}
+
+	vector <double> ImL;
+	vector <double> Ima;
+	vector <double> Imb;
+	gradvector(l_channel,ImL);
+	gradvector(a_channel,Ima);
+	gradvector(b_channel,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);
+	}
+	lab.release();
+	l_channel.release();
+	a_channel.release();
+	b_channel.release();
+
+	ImL.clear();
+	Ima.clear();
+	Imb.clear();
+	
+}
+
+void Decolor::add_vector(vector < vector <int> > &comb, int r,int g,int b)
+{
+	static int idx =0;
+	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)
+{
+	static int idx1 =0;
+	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)
+{
+	Mat curIm = Mat(img.size(),CV_32FC1);
+	Mat red = Mat(img.size(),CV_32FC1);
+	Mat green = Mat(img.size(),CV_32FC1);
+	Mat blue = Mat(img.size(),CV_32FC1);
+
+	for(int i=0;i<img.size().height;i++)
+		for(int j=0;j<img.size().width;j++)
+		{
+			red.at<float>(i,j) = img.at<float>(i,j*3+2);
+			green.at<float>(i,j) = img.at<float>(i,j*3+1);
+			blue.at<float>(i,j) = img.at<float>(i,j*3+0);
+		}
+	
+	vector <double> Rg;
+	vector <double> Gg;
+	vector <double> Bg;
+
+	vector <double> t1;
+	vector <double> t2;
+	vector <double> t3;
+	
+	vector <double> tmp1;
+	vector <double> tmp2;
+	vector <double> tmp3;
+
+	gradvector(red,Rg);
+	gradvector(green,Gg);
+	gradvector(blue,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);
+	}
+	for(unsigned int i=0;i<Gg.size();i++)
+	{
+		if(Gg[i] > level)
+			t2.push_back(1.0);
+		else
+			t2.push_back(0.0);
+	}
+	for(unsigned int i=0;i<Bg.size();i++)
+	{
+		if(Bg[i] > level)
+			t3.push_back(1.0);
+		else
+			t3.push_back(0.0);
+	}
+	for(unsigned int i=0;i<Rg.size();i++)
+	{
+		if(Rg[i] < -1.0*level)
+			tmp1.push_back(1.0);
+		else
+			tmp1.push_back(0.0);
+	}
+	for(unsigned int i=0;i<Gg.size();i++)
+	{
+		if(Gg[i] < -1.0*level)
+			tmp2.push_back(1.0);
+		else
+			tmp2.push_back(0.0);
+	}
+	for(unsigned int i=0;i<Bg.size();i++)
+	{
+		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();
+
+	red.release();
+	green.release();
+	blue.release();
+	curIm.release();
+
+	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;
+	colorGrad(img,Cg);
+	
+	Mat curIm = Mat(img.size(),CV_32FC1);
+	Mat red = Mat(img.size(),CV_32FC1);
+	Mat green = Mat(img.size(),CV_32FC1);
+	Mat blue = Mat(img.size(),CV_32FC1);
+
+	for(int i=0;i<img.size().height;i++)
+		for(int j=0;j<img.size().width;j++)
+		{
+			red.at<float>(i,j) = img.at<float>(i,j*3+2);
+			green.at<float>(i,j) = img.at<float>(i,j*3+1);
+			blue.at<float>(i,j) = img.at<float>(i,j*3+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,r,g,b);
+					for(int i = 0;i<h;i++)
+						for(int j=0;j<w;j++)
+							curIm.at<float>(i,j)=
+								pow(red.at<float>(i,j),r)*pow(green.at<float>(i,j),g)*
+									pow(blue.at<float>(i,j),b);
+					vector <double> curGrad;
+					gradvector(curIm,curGrad);
+					add_to_vector_poly(polyGrad,curGrad);
+				}
+			}
+
+	red.release();
+	green.release();
+	blue.release();
+	curIm.release();
+}
+
+void Decolor::wei_update_matrix(vector < vector <double> > &poly, vector <double> &Cg, Mat &X)
+{
+	Mat P = Mat(poly.size(),poly[0].size(), CV_32FC1);
+	Mat A = Mat(poly.size(),poly.size(), CV_32FC1);
+
+	for(unsigned int i =0;i<poly.size();i++)
+		for(unsigned int j=0;j<poly[0].size();j++)
+			P.at<float>(i,j) = poly[i][j];
+
+	Mat P_trans = P.t();	
+	Mat B = Mat(poly.size(),poly[0].size(), CV_32FC1);
+	for(unsigned int i =0;i < poly.size();i++)
+	{
+		for(unsigned int j=0;j<Cg.size();j++)
+			B.at<float>(i,j) = poly[i][j]*Cg[j];
+	}
+
+	A = P*P_trans;
+	solve(A, B, X, DECOMP_NORMAL);
+
+	P.release();
+	A.release();
+	B.release();
+
+}
+
+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;
+
+	Mat red = Mat(img.size(),CV_32FC1);
+	Mat green = Mat(img.size(),CV_32FC1);
+	Mat blue = Mat(img.size(),CV_32FC1);
+
+	for(int i=0;i<img.size().height;i++)
+		for(int j=0;j<img.size().width;j++)
+		{
+			red.at<float>(i,j) = img.at<float>(i,j*3+2);
+			green.at<float>(i,j) = img.at<float>(i,j*3+1);
+			blue.at<float>(i,j) = img.at<float>(i,j*3+0);
+		}
+
+	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) +
+								wei[kk]*pow(red.at<float>(i,j),r)*pow(green.at<float>(i,j),g)*
+									pow(blue.at<float>(i,j),b);
+
+					kk=kk+1;
+				}
+
+	double minval = INT_MAX;
+	double maxval = INT_MIN;
+
+	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);
+		}
+
+	for(int i=0;i<h;i++)
+		for(int j=0;j<w;j++)
+			Gray.at<float>(i,j) = (Gray.at<float>(i,j) - minval)/(maxval - minval);
+
+	red.release();
+	green.release();
+	blue.release();
+}
diff --git a/modules/photo/test/test_decolor.cpp b/modules/photo/test/test_decolor.cpp
new file mode 100644
index 0000000000..3edec908a8
--- /dev/null
+++ b/modules/photo/test/test_decolor.cpp
@@ -0,0 +1,34 @@
+#include "test_precomp.hpp"
+#include "opencv2/photo.hpp"
+#include <string>
+
+using namespace cv;
+using namespace std;
+
+#ifdef DUMP_RESULTS
+#  define DUMP(image, path) imwrite(path, image)
+#else
+#  define DUMP(image, path)
+#endif
+
+
+TEST(Photo_Decolor, regression)
+{
+        string folder = string(cvtest::TS::ptr()->get_data_path()) + "decolor/";
+        string original_path = folder + "color_image_1.png";
+        string expected_path = folder + "grayscale_image_1.png";
+
+        Mat original = imread(original_path, IMREAD_COLOR);
+        Mat expected = imread(expected_path, IMREAD_GRAYSCALE);
+
+        ASSERT_FALSE(original.empty()) << "Could not load input image " << original_path;
+        ASSERT_FALSE(expected.empty()) << "Could not load reference image " << expected_path;
+
+        Mat result;
+        decolor(original, result);
+
+        DUMP(result, expected_path + ".res.png");
+
+        ASSERT_EQ(0, norm(result != expected));
+}
+