diff --git a/04/do_sprawdzenia/cpp/blur_gaussian.cpp b/04/do_sprawdzenia/cpp/blur_gaussian.cpp
new file mode 100644
index 0000000..d4d97c4
--- /dev/null
+++ b/04/do_sprawdzenia/cpp/blur_gaussian.cpp
@@ -0,0 +1,46 @@
+#include "blur_gaussian.h"
+
+BlurGaussian::BlurGaussian(PNM* img) :
+    Convolution(img)
+{
+}
+
+BlurGaussian::BlurGaussian(PNM* img, ImageViewer* iv) :
+    Convolution(img, iv)
+{
+}
+
+PNM* BlurGaussian::transform()
+{
+    emit message("Blurring...");
+
+    int size = getParameter("size").toInt();
+    radius = (size/2)+1;
+    sigma = getParameter("sigma").toDouble();
+
+    return convolute(getMask(size, Normalize), RepeatEdge);
+}
+
+math::matrix<float> BlurGaussian::getMask(int size, Mode)
+{
+    math::matrix<float> mask(size, size);
+
+    for (int i = 0; i < size; i++)
+    {
+        for (int j = 0; j < size; j++)
+        {
+            mask(i,j) = getGauss(i-radius, j-radius, sigma);
+        }
+    }
+
+
+    return mask;
+}
+
+float BlurGaussian::getGauss(int x, int y, float sigma)
+{    
+    // Calculate a two-dimensional Gaussian function:
+    return (1 / (2 * M_PI * pow(sigma, 2))) * exp(-(pow(x, 2) + pow(y, 2)) / (2 * pow(sigma, 2)));
+
+}
+
diff --git a/04/do_sprawdzenia/cpp/blur_linear.cpp b/04/do_sprawdzenia/cpp/blur_linear.cpp
new file mode 100644
index 0000000..11ddc59
--- /dev/null
+++ b/04/do_sprawdzenia/cpp/blur_linear.cpp
@@ -0,0 +1,40 @@
+#include "blur_linear.h"
+
+BlurLinear::BlurLinear(PNM* img) :
+    Convolution(img)
+{
+}
+
+BlurLinear::BlurLinear(PNM* img, ImageViewer* iv) :
+    Convolution(img, iv)
+{
+}
+
+PNM* BlurLinear::transform()
+{
+    int maskSize = getParameter("size").toInt();
+    QList<QVariant> tmpMask = getParameter("mask").toList();
+    bool normalize = getParameter("normalize").toBool();
+
+    math::matrix<float> mask(maskSize, maskSize);
+
+    int maskValCount = 0;
+
+    for (int i=0; i < maskSize; i++)
+    {
+        for (int j=0; j < maskSize; j++)
+        {
+            if (normalize)
+            {
+                mask[i][j] = tmpMask.at(maskValCount).toDouble() / Convolution::sum(mask);
+                maskValCount++;
+            }
+            else
+            {
+                mask[i][j] = tmpMask.at(maskValCount).toDouble();
+                maskValCount++;
+            }
+        }
+    }
+    return convolute(mask, RepeatEdge);
+}
diff --git a/04/do_sprawdzenia/cpp/blur_uniform.cpp b/04/do_sprawdzenia/cpp/blur_uniform.cpp
new file mode 100644
index 0000000..71a3c85
--- /dev/null
+++ b/04/do_sprawdzenia/cpp/blur_uniform.cpp
@@ -0,0 +1,25 @@
+#include "blur_uniform.h"
+
+BlurUniform::BlurUniform(PNM* img) :
+    Convolution(img)
+{
+}
+
+BlurUniform::BlurUniform(PNM* img, ImageViewer* iv) :
+    Convolution(img, iv)
+{
+}
+
+math::matrix<float> BlurUniform::getMask(int size, Mode)
+{
+    math::matrix<float> mask(size, size);
+
+    for (int i=0; i < size; i++)
+    {
+        for (int j=0; j < size; j++)
+        {
+            mask[i][j] = 1;
+        }
+    }
+    return mask;
+}
diff --git a/04/do_sprawdzenia/cpp/convolution.cpp b/04/do_sprawdzenia/cpp/convolution.cpp
new file mode 100644
index 0000000..a35e9e1
--- /dev/null
+++ b/04/do_sprawdzenia/cpp/convolution.cpp
@@ -0,0 +1,173 @@
+#include "convolution.h"
+
+/** Overloaded constructor */
+Convolution::Convolution(PNM* img) :
+    Transformation(img)
+{
+}
+
+Convolution::Convolution(PNM* img, ImageViewer* iv) :
+    Transformation(img, iv)
+{
+}
+
+/** Returns a convoluted form of the image */
+PNM* Convolution::transform()
+{
+    return convolute(getMask(3, Normalize), RepeatEdge);
+}
+
+/** Returns a sizeXsize matrix with the center point equal 1.0 */
+math::matrix<float> Convolution::getMask(int size, Mode mode = Normalize)
+{
+    math::matrix<float> mask(size, size);
+
+    // Get center of image
+    int center = size/2;
+
+    // Get mask
+    for (int i=0; i < size; i++)
+    {
+        for (int j=0; j < size; j++)
+        {
+            if (i==j && i == center && j == center)
+            {
+                mask[i][j] = 1;
+            }
+            else
+            {
+                mask[i][j] = 0;
+            }
+        }
+    }
+    return mask;
+}
+
+/** Does the convolution process for all pixels using the given mask. */
+PNM* Convolution::convolute(math::matrix<float> mask, Mode mode = RepeatEdge)
+{
+    int width  = image->width(),
+        height = image->height();
+
+    PNM* newImage = new PNM(width, height, image->format());
+
+    float weight = Convolution::sum(mask);
+
+    math::matrix<float> reflection = Convolution::reflection(mask);
+    for (int x=0; x < width ; x++)
+    {
+        for (int y=0; y < height; y++)
+        {
+             math::matrix<float> rAcc = Convolution::join(getWindow(x, y, mask.rowno(), Transformation::RChannel, mode), reflection);
+             math::matrix<float> gAcc = Convolution::join(getWindow(x, y, mask.rowno(), Transformation::GChannel, mode), reflection);
+             math::matrix<float> bAcc = Convolution::join(getWindow(x, y, mask.rowno(), Transformation::BChannel, mode), reflection);
+
+             float rAccSum = Convolution::sum(rAcc);
+             float gAccSum = Convolution::sum(gAcc);
+             float bAccSum = Convolution::sum(bAcc);
+
+
+             if (weight != 0)
+             {
+                 rAccSum = rAccSum / weight;
+                 gAccSum = gAccSum / weight;
+                 bAccSum = bAccSum / weight;
+             }
+
+             // Calculate Red Accumulate Sum
+             if (rAccSum < 0)
+             {
+                 rAccSum = 0;
+             }
+             else if (rAccSum > 255)
+             {
+                 rAccSum = 255;
+             }
+
+             // Calculate Green Accumulate Sum
+             if (gAccSum < 0)
+             {
+                 gAccSum = 0;
+             }
+             else if (gAccSum > 255)
+             {
+                 gAccSum = 255;
+             }
+
+             // Calculate Blue Accumulate Sum
+             if (bAccSum < 0)
+             {
+                 bAccSum = 0;
+             }
+             else if(bAccSum > 255)
+             {
+                 bAccSum = 255;
+             }
+
+             // Create pixel
+             QColor newPixel = QColor(rAccSum, gAccSum, bAccSum);
+
+             // Set pixel
+             newImage->setPixel(x,y, newPixel.rgb());
+        }
+    }
+    return newImage;
+}
+
+/** Joins to matrices by multiplying the A[i,j] with B[i,j].
+  * Warning! Both Matrices must be squares with the same size!
+  */
+const math::matrix<float> Convolution::join(math::matrix<float> A, math::matrix<float> B)
+{
+    int size = A.rowno();
+    math::matrix<float> C(size, size);
+
+
+    for (int i=0; i < size; i++)
+    {
+        for (int j=0; j < size; j++)
+        {
+           // Multiplication
+           C[i][j] = A[i][j] * B[i][j];
+        }
+    }
+
+    return C;
+}
+
+/** Sums all of the matrixes elements */
+const float Convolution::sum(const math::matrix<float> A)
+{
+    float sum = 0.0;
+
+    int size = A.rowno();
+
+    for (int i=0; i<size; i++)
+    {
+        for (int j=0; j<size; j++)
+        {
+            // Summation
+            sum = sum + A[i][j];
+        }
+    }
+    return sum;
+}
+
+
+/** Returns reflected version of a matrix */
+const math::matrix<float> Convolution::reflection(const math::matrix<float> A)
+{
+    int size = A.rowno();
+    math::matrix<float> C(size, size);
+
+
+    for (int i=0; i < size; i++)
+    {
+        for (int j=0; j < size; j++)
+        {
+            C[i][j] = A[size-i-1][size-j-1];
+        }
+    }
+
+    return C;
+}
diff --git a/app/cpp/mysimplegimp/src/core/transformations/blur_gaussian.cpp b/app/cpp/mysimplegimp/src/core/transformations/blur_gaussian.cpp
index 3eba6e4..d4d97c4 100644
--- a/app/cpp/mysimplegimp/src/core/transformations/blur_gaussian.cpp
+++ b/app/cpp/mysimplegimp/src/core/transformations/blur_gaussian.cpp
@@ -25,15 +25,22 @@ math::matrix<float> BlurGaussian::getMask(int size, Mode)
 {
     math::matrix<float> mask(size, size);
 
-    qDebug() << Q_FUNC_INFO << "Not implemented yet!";
+    for (int i = 0; i < size; i++)
+    {
+        for (int j = 0; j < size; j++)
+        {
+            mask(i,j) = getGauss(i-radius, j-radius, sigma);
+        }
+    }
+
 
     return mask;
 }
 
 float BlurGaussian::getGauss(int x, int y, float sigma)
 {    
-    qDebug() << Q_FUNC_INFO << "Not implemented yet!";
+    // Calculate a two-dimensional Gaussian function:
+    return (1 / (2 * M_PI * pow(sigma, 2))) * exp(-(pow(x, 2) + pow(y, 2)) / (2 * pow(sigma, 2)));
 
-    return 0;
 }
 
diff --git a/app/cpp/mysimplegimp/src/core/transformations/blur_linear.cpp b/app/cpp/mysimplegimp/src/core/transformations/blur_linear.cpp
index c24f9e8..11ddc59 100644
--- a/app/cpp/mysimplegimp/src/core/transformations/blur_linear.cpp
+++ b/app/cpp/mysimplegimp/src/core/transformations/blur_linear.cpp
@@ -18,7 +18,23 @@ PNM* BlurLinear::transform()
 
     math::matrix<float> mask(maskSize, maskSize);
 
-    qDebug() << Q_FUNC_INFO << "Not implemented yet!";
+    int maskValCount = 0;
 
+    for (int i=0; i < maskSize; i++)
+    {
+        for (int j=0; j < maskSize; j++)
+        {
+            if (normalize)
+            {
+                mask[i][j] = tmpMask.at(maskValCount).toDouble() / Convolution::sum(mask);
+                maskValCount++;
+            }
+            else
+            {
+                mask[i][j] = tmpMask.at(maskValCount).toDouble();
+                maskValCount++;
+            }
+        }
+    }
     return convolute(mask, RepeatEdge);
 }
diff --git a/app/cpp/mysimplegimp/src/core/transformations/blur_uniform.cpp b/app/cpp/mysimplegimp/src/core/transformations/blur_uniform.cpp
index 36604c4..71a3c85 100644
--- a/app/cpp/mysimplegimp/src/core/transformations/blur_uniform.cpp
+++ b/app/cpp/mysimplegimp/src/core/transformations/blur_uniform.cpp
@@ -14,7 +14,12 @@ math::matrix<float> BlurUniform::getMask(int size, Mode)
 {
     math::matrix<float> mask(size, size);
 
-    qDebug() << Q_FUNC_INFO << "Not implemented yet!";
-
+    for (int i=0; i < size; i++)
+    {
+        for (int j=0; j < size; j++)
+        {
+            mask[i][j] = 1;
+        }
+    }
     return mask;
 }
diff --git a/app/cpp/mysimplegimp/src/core/transformations/convolution.cpp b/app/cpp/mysimplegimp/src/core/transformations/convolution.cpp
index 71864b7..a35e9e1 100644
--- a/app/cpp/mysimplegimp/src/core/transformations/convolution.cpp
+++ b/app/cpp/mysimplegimp/src/core/transformations/convolution.cpp
@@ -22,8 +22,24 @@ math::matrix<float> Convolution::getMask(int size, Mode mode = Normalize)
 {
     math::matrix<float> mask(size, size);
 
-    qDebug() << Q_FUNC_INFO << "Not implemented yet!";
+    // Get center of image
+    int center = size/2;
 
+    // Get mask
+    for (int i=0; i < size; i++)
+    {
+        for (int j=0; j < size; j++)
+        {
+            if (i==j && i == center && j == center)
+            {
+                mask[i][j] = 1;
+            }
+            else
+            {
+                mask[i][j] = 0;
+            }
+        }
+    }
     return mask;
 }
 
@@ -35,8 +51,66 @@ PNM* Convolution::convolute(math::matrix<float> mask, Mode mode = RepeatEdge)
 
     PNM* newImage = new PNM(width, height, image->format());
 
-    qDebug() << Q_FUNC_INFO << "Not implemented yet!";
+    float weight = Convolution::sum(mask);
 
+    math::matrix<float> reflection = Convolution::reflection(mask);
+    for (int x=0; x < width ; x++)
+    {
+        for (int y=0; y < height; y++)
+        {
+             math::matrix<float> rAcc = Convolution::join(getWindow(x, y, mask.rowno(), Transformation::RChannel, mode), reflection);
+             math::matrix<float> gAcc = Convolution::join(getWindow(x, y, mask.rowno(), Transformation::GChannel, mode), reflection);
+             math::matrix<float> bAcc = Convolution::join(getWindow(x, y, mask.rowno(), Transformation::BChannel, mode), reflection);
+
+             float rAccSum = Convolution::sum(rAcc);
+             float gAccSum = Convolution::sum(gAcc);
+             float bAccSum = Convolution::sum(bAcc);
+
+
+             if (weight != 0)
+             {
+                 rAccSum = rAccSum / weight;
+                 gAccSum = gAccSum / weight;
+                 bAccSum = bAccSum / weight;
+             }
+
+             // Calculate Red Accumulate Sum
+             if (rAccSum < 0)
+             {
+                 rAccSum = 0;
+             }
+             else if (rAccSum > 255)
+             {
+                 rAccSum = 255;
+             }
+
+             // Calculate Green Accumulate Sum
+             if (gAccSum < 0)
+             {
+                 gAccSum = 0;
+             }
+             else if (gAccSum > 255)
+             {
+                 gAccSum = 255;
+             }
+
+             // Calculate Blue Accumulate Sum
+             if (bAccSum < 0)
+             {
+                 bAccSum = 0;
+             }
+             else if(bAccSum > 255)
+             {
+                 bAccSum = 255;
+             }
+
+             // Create pixel
+             QColor newPixel = QColor(rAccSum, gAccSum, bAccSum);
+
+             // Set pixel
+             newImage->setPixel(x,y, newPixel.rgb());
+        }
+    }
     return newImage;
 }
 
@@ -48,7 +122,15 @@ const math::matrix<float> Convolution::join(math::matrix<float> A, math::matrix<
     int size = A.rowno();
     math::matrix<float> C(size, size);
 
-    qDebug() << Q_FUNC_INFO << "Not implemented yet!";
+
+    for (int i=0; i < size; i++)
+    {
+        for (int j=0; j < size; j++)
+        {
+           // Multiplication
+           C[i][j] = A[i][j] * B[i][j];
+        }
+    }
 
     return C;
 }
@@ -58,10 +140,17 @@ const float Convolution::sum(const math::matrix<float> A)
 {
     float sum = 0.0;
 
-    qDebug() << Q_FUNC_INFO << "Not implemented yet!";
+    int size = A.rowno();
 
+    for (int i=0; i<size; i++)
+    {
+        for (int j=0; j<size; j++)
+        {
+            // Summation
+            sum = sum + A[i][j];
+        }
+    }
     return sum;
-
 }
 
 
@@ -71,7 +160,14 @@ const math::matrix<float> Convolution::reflection(const math::matrix<float> A)
     int size = A.rowno();
     math::matrix<float> C(size, size);
 
-    qDebug() << Q_FUNC_INFO << "Not implemented yet!";
+
+    for (int i=0; i < size; i++)
+    {
+        for (int j=0; j < size; j++)
+        {
+            C[i][j] = A[size-i-1][size-j-1];
+        }
+    }
 
     return C;
 }
diff --git a/app/cpp/mysimplegimp/src/core/transformations/transformation.cpp b/app/cpp/mysimplegimp/src/core/transformations/transformation.cpp
index 18a3e0a..cf1aca0 100644
--- a/app/cpp/mysimplegimp/src/core/transformations/transformation.cpp
+++ b/app/cpp/mysimplegimp/src/core/transformations/transformation.cpp
@@ -103,8 +103,14 @@ QRgb Transformation::getPixel(int x, int y, Mode mode)
  */
 QRgb Transformation::getPixelCyclic(int x, int y)
 {
-    qDebug() << Q_FUNC_INFO << "Not implemented yet!";
+    int width = image->width();
+    int height = image->height();
 
+    // Return a pixel by looping the image
+    x = x % width;
+    y = y % height;
+
+    // Return pixel
     return image->pixel(x,y);
 }
 
@@ -114,8 +120,15 @@ QRgb Transformation::getPixelCyclic(int x, int y)
   */
 QRgb Transformation::getPixelNull(int x, int y)
 {
-    qDebug() << Q_FUNC_INFO << "Not implemented yet!";
+    int width  = image->width();
+    int height = image->height();
 
+    // Return black as a pixel when out of range
+    if (x > width || x < 0 || y > height || y < 0){
+        return Qt::black;
+    }
+
+    // Return pixel
     return image->pixel(x,y);
 }
 
@@ -126,7 +139,19 @@ QRgb Transformation::getPixelNull(int x, int y)
   */
 QRgb Transformation::getPixelRepeat(int x, int y)
 {
-    qDebug() << Q_FUNC_INFO << "Not implemented yet!";
+    int width  = image->width();
+    int height = image->height();
+
+    // Copy nearest edge pixel
+    if (x<0 && y<0) return image->pixel(0,0);
+    else if (x>=width && y<0) return image->pixel(width-1,0);
+    else if (x>=width && y>=height) return image->pixel(width-1,height-1);
+    else if (x<0 && y>=height) return image->pixel(0,height-1);
+    else if (x<0) return image->pixel(0,y);
+    else if (y<0) return image->pixel(x,0);
+    else if (x>=width) return image->pixel(width-1,y);
+    else if (y>=height) return image->pixel(x,height-1);
+    else return image->pixel(x,y);
 
     return image->pixel(x,y);
 }
@@ -138,8 +163,33 @@ math::matrix<float> Transformation::getWindow(int x, int y, int size,
 {
     math::matrix<float> window(size,size);
 
-    qDebug() << Q_FUNC_INFO << "Not implemented yet!";
+    // Calculate center
+    int center = size/2;
 
+    // Get window
+    for (int i=0; i < size; i++)
+    {
+        for (int j=0; j < size; j++)
+        {
+            QRgb pixelVal = getPixel(x-center+i, y-center+j, mode);
+            if (channel == RChannel)
+            {
+                window[i][j] = qRed(pixelVal);
+            }
+            else if (channel == GChannel)
+            {
+                window[i][j] = qGreen(pixelVal);
+            }
+            else if (channel == BChannel)
+            {
+                window[i][j] = qBlue(pixelVal);
+            }
+            else if (channel == LChannel)
+            {
+                window[i][j] = qGray(pixelVal);
+            }
+        }
+    }
     return window;
 }