diff --git a/src/core/transformations/edge_gradient.cpp b/src/core/transformations/edge_gradient.cpp
index a36a5b8..d9e87d7 100644
--- a/src/core/transformations/edge_gradient.cpp
+++ b/src/core/transformations/edge_gradient.cpp
@@ -22,10 +22,43 @@ PNM* EdgeGradient::horizontalDetection()
 
 PNM* EdgeGradient::transform()
 {
+
     PNM* newImage = new PNM(image->width(), image->height(), image->format());
+    PNM* imageX;
+    imageX=verticalDetection();
+    PNM* imageY;
+    imageY=horizontalDetection();
 
-    qDebug() << Q_FUNC_INFO << "Not implemented yet!";
 
-    return newImage;
+
+    for(int i=0;i<image->width();i++)
+    {
+        for(int j=0;j<image->height();j++)
+        {
+            float imageX_red = qRed(imageX->pixel(i,j));
+            float imageX_green = qGreen(imageX->pixel(i,j));
+            float imageX_blue = qBlue(imageX->pixel(i,j));
+            float imageY_red = qRed(imageY->pixel(i,j));
+            float imageY_green = qGreen(imageY->pixel(i,j));
+            float imageY_blue = qBlue(imageY->pixel(i,j));
+
+            float ImageNew_red=getEdgeValue(imageX_red, imageY_red);
+            float ImageNew_green=getEdgeValue(imageX_green, imageY_green);
+            float ImageNew_blue=getEdgeValue(imageX_blue, imageY_blue);
+
+            newImage->setPixel(i,j, QColor(ImageNew_red, ImageNew_green, ImageNew_blue).rgb());
+
+        }
+    }
+
+   return newImage;
 }
 
+float EdgeGradient::getEdgeValue(int x, int y)
+{
+
+    return sqrt(pow(x,2)+pow(y,2));
+
+}
+
+
diff --git a/src/core/transformations/edge_gradient.h b/src/core/transformations/edge_gradient.h
index 331ccc1..158d64a 100644
--- a/src/core/transformations/edge_gradient.h
+++ b/src/core/transformations/edge_gradient.h
@@ -10,6 +10,7 @@ public:
     EdgeGradient(PNM*, ImageViewer*);
 
     virtual PNM* transform();
+    static float getEdgeValue(int, int);
 
     PNM* verticalDetection();
     PNM* horizontalDetection();
diff --git a/src/core/transformations/edge_laplacian.cpp b/src/core/transformations/edge_laplacian.cpp
index 8c26718..9d7714c 100644
--- a/src/core/transformations/edge_laplacian.cpp
+++ b/src/core/transformations/edge_laplacian.cpp
@@ -14,8 +14,15 @@ math::matrix<float> EdgeLaplacian::getMask(int, Mode)
 {
     int size = getParameter("size").toInt();
     math::matrix<float> mask(size, size);
+    int r=size/2;
+
+    for (int x=0; x<size; x++)
+            for (int y=0; y<size; y++)
+                mask[x][y]=-1;
+
+
+    mask[r][r]=(size*size)-1;
 
-    qDebug() << Q_FUNC_INFO << "Not implemented yet!";
 
     return mask;
 }
diff --git a/src/core/transformations/edge_laplacian_of_gauss.cpp b/src/core/transformations/edge_laplacian_of_gauss.cpp
index dcacb71..0ac338d 100644
--- a/src/core/transformations/edge_laplacian_of_gauss.cpp
+++ b/src/core/transformations/edge_laplacian_of_gauss.cpp
@@ -18,17 +18,24 @@ math::matrix<float> EdgeLaplaceOfGauss::getMask(int, Mode)
     double sigma = getParameter("sigma").toDouble();
 
     math::matrix<float> mask(size, size);
+    int r=size/2;
+
+    for(int i=0;i<size;i++)
+        for(int j=0;j<size;j++)
+            mask[i][j]=getLoG(i-r, j-r, sigma);
 
-    qDebug() << Q_FUNC_INFO << "Not implemented yet!";
 
     return mask;
 }
 
 float EdgeLaplaceOfGauss::getLoG(int x, int y, float s)
 {
-    qDebug() << Q_FUNC_INFO << "Not implemented yet!";
 
-    return 0;
+    float results;
+
+    results=(((pow(x,2)+pow(y,2))-2)/pow(s,2))*BlurGaussian::getGauss(x,y,s);
+
+    return results;
 }
 
 int EdgeLaplaceOfGauss::getSize()
diff --git a/src/core/transformations/edge_prewitt.cpp b/src/core/transformations/edge_prewitt.cpp
index d6585eb..0f34fd3 100644
--- a/src/core/transformations/edge_prewitt.cpp
+++ b/src/core/transformations/edge_prewitt.cpp
@@ -14,6 +14,36 @@ EdgePrewitt::EdgePrewitt(PNM*img, ImageViewer* iv) :
 
 void EdgePrewitt::prepareMatrices()
 {
-    qDebug() << Q_FUNC_INFO << "Not implemented yet!";
+    int size = 3;
+
+
+    this->g_x =  math::matrix<float>(size,size);
+    this->g_y =  math::matrix<float>(size,size);
+
+
+    g_x[0][0]=-1;
+    g_x[0][1]=0;
+    g_x[0][2]=1;
+    g_x[1][0]=-1;
+    g_x[1][1]=0;
+    g_x[1][2]=1;
+    g_x[2][0]=-1;
+    g_x[2][1]=-0;
+    g_x[2][2]=1;
+
+
+    g_y[0][0]=-1;
+    g_y[0][1]=-1;
+    g_y[0][2]=-1;
+    g_y[1][0]=0;
+    g_y[1][1]=0;
+    g_y[1][2]=0;
+    g_y[2][0]=1;
+    g_y[2][1]=1;
+    g_y[2][2]=1;
+
+
+
+
 }
 
diff --git a/src/core/transformations/edge_roberts.cpp b/src/core/transformations/edge_roberts.cpp
index 0428da9..99a29c8 100644
--- a/src/core/transformations/edge_roberts.cpp
+++ b/src/core/transformations/edge_roberts.cpp
@@ -14,5 +14,22 @@ EdgeRoberts::EdgeRoberts(PNM* img, ImageViewer* iv) :
 
 void EdgeRoberts::prepareMatrices()
 {
-    qDebug() << Q_FUNC_INFO << "Not implemented yet!";
+
+    int size = 2;
+
+
+    this->g_x =  math::matrix<float>(size,size);
+    this->g_y =  math::matrix<float>(size,size);
+
+
+    g_x[0][0]=1;
+    g_x[0][1]=0;
+    g_x[1][0]=0;
+    g_x[1][1]=-1;
+
+    g_y[0][0]=0;
+    g_y[0][1]=1;
+    g_y[1][0]=-1;
+    g_y[1][1]=0;
+
 }
diff --git a/src/core/transformations/edge_sobel.cpp b/src/core/transformations/edge_sobel.cpp
index 6ef4bff..d99a057 100644
--- a/src/core/transformations/edge_sobel.cpp
+++ b/src/core/transformations/edge_sobel.cpp
@@ -14,7 +14,33 @@ EdgeSobel::EdgeSobel(PNM* img) :
 
 void EdgeSobel::prepareMatrices()
 {
-    qDebug() << Q_FUNC_INFO << "Not implemented yet!";
+    int size = 3;
+
+
+    this->g_x =  math::matrix<float>(size,size);
+    this->g_y =  math::matrix<float>(size,size);
+
+
+    g_x[0][0]=-1;
+    g_x[0][1]=0;
+    g_x[0][2]=1;
+    g_x[1][0]=-2;
+    g_x[1][1]=0;
+    g_x[1][2]=2;
+    g_x[2][0]=-1;
+    g_x[2][1]=-0;
+    g_x[2][2]=1;
+
+
+    g_y[0][0]=-1;
+    g_y[0][1]=-2;
+    g_y[0][2]=-1;
+    g_y[1][0]=0;
+    g_y[1][1]=0;
+    g_y[1][2]=0;
+    g_y[2][0]=1;
+    g_y[2][1]=2;
+    g_y[2][2]=1;
 }
 
 math::matrix<float>* EdgeSobel::rawHorizontalDetection()
diff --git a/src/core/transformations/edge_zero.cpp b/src/core/transformations/edge_zero.cpp
index 541943f..b180705 100644
--- a/src/core/transformations/edge_zero.cpp
+++ b/src/core/transformations/edge_zero.cpp
@@ -20,11 +20,66 @@ PNM* EdgeZeroCrossing::transform()
     int    size  = getParameter("size").toInt();
     double sigma = getParameter("sigma").toDouble();
     int    t     = getParameter("threshold").toInt();
+    int v = 128;
+    int r=size/2;
 
     PNM* newImage = new PNM(width, height, QImage::Format_Grayscale8);
 
-    qDebug() << Q_FUNC_INFO << "Not implemented yet!";
+    EdgeLaplaceOfGauss * gaussImage = new EdgeLaplaceOfGauss(image);
+
+    for (int x=0; x<width; x++)
+            for (int y=0; y<height; y++)
+            {
+                math::matrix<float> wR = gaussImage->getWindow(x,y,size,RChannel,CyclicEdge);
+                math::matrix<float> wB = gaussImage->getWindow(x,y,size,BChannel,CyclicEdge);
+                math::matrix<float> wG = gaussImage->getWindow(x,y,size,GChannel,CyclicEdge);
+
+                float maxR=maxValue(wR,size);
+                float maxG=maxValue(wG,size);
+                float maxB=maxValue(wB,size);
+                float minR=minValue(wR,size);
+                float minG=minValue(wG,size);
+                float minB=minValue(wB,size);
+
+                if (minR < v-t && maxR > v+t)
+                        newImage->setPixel(x, y,gaussImage->getPixel(x,y,CyclicEdge));
+                else if (minG < v-t && maxG>v+t)
+                        newImage->setPixel(x, y, gaussImage->getPixel(x,y,CyclicEdge));
+                else if (minB < v-t && maxB > v+t)
+                        newImage->setPixel(x, y, gaussImage->getPixel(x,y,CyclicEdge));
+                else
+                {
+                         newImage->setPixel(x, y, 0);
+                }
+            }
+
+
+
+
 
     return newImage;
 }
 
+float EdgeZeroCrossing::maxValue(math::matrix<float> mask, int size)
+{
+    float max=mask[0][0];
+
+    for (int x=0; x<size; x++)
+            for (int y=0; y<size; y++)
+                    if (mask[x][y] > max)
+                            max=mask[x][y];
+
+    return max;
+}
+
+float EdgeZeroCrossing::minValue(math::matrix<float> mask, int size)
+{
+    float min=mask[0][0];
+
+    for (int x=0; x<size; x++)
+            for (int y=0; y<size; y++)
+                    if (mask[x][y] < min)
+                            min=mask[x][y];
+
+    return min;
+}
diff --git a/src/core/transformations/edge_zero.h b/src/core/transformations/edge_zero.h
index 0380e42..d2389dd 100644
--- a/src/core/transformations/edge_zero.h
+++ b/src/core/transformations/edge_zero.h
@@ -10,6 +10,8 @@ public:
     EdgeZeroCrossing(PNM*, ImageViewer*);
 
     virtual PNM* transform();
+    float maxValue(math::matrix<float> mask, int size);
+    float minValue(math::matrix<float> mask, int size);
 };
 
 #endif // EDGE_ZERO_H