From b801fbda96299f719cb3fe4ff7c141e61a606476 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jaros=C5=82aw=20Wieczorek?= <jarwie@st.amu.edu.pl>
Date: Thu, 15 Apr 2021 20:32:58 +0200
Subject: [PATCH] Fix bin_gradient.cpp

---
 .../src/core/transformations/bin_gradient.cpp | 75 +++++++++++--------
 1 file changed, 43 insertions(+), 32 deletions(-)

diff --git a/app/cpp/mysimplegimp/src/core/transformations/bin_gradient.cpp b/app/cpp/mysimplegimp/src/core/transformations/bin_gradient.cpp
index a495bc7..d07edb2 100644
--- a/app/cpp/mysimplegimp/src/core/transformations/bin_gradient.cpp
+++ b/app/cpp/mysimplegimp/src/core/transformations/bin_gradient.cpp
@@ -17,51 +17,62 @@ PNM* BinarizationGradient::transform()
     int height = image->height();
 
     PNM* newImage = new PNM(width, height, QImage::Format_Mono);
+    int numerator = 0;
+    int denominator = 0;
 
-    // Create variables
-    // The pixel value at point (i,j)
-    float I=0;
+    // Gx
+    int Gx = 0;
 
-    // The first component of the gradient at point (i,j)
-    float Gx=0;
+    // Gy
+    int Gy = 0;
 
-    // The second component of the gradient at point (i,j)
-    float Gy=0;
+    int G = 0;
+    int T = 0;
 
+    //PNM* newImage = new PNM(width, height, QImage::Format_Mono);
 
-    for (int x=0; x < width; x++)
+    for (int x = 0; x < width; x++)
     {
-        for(int y=0; y < height; y++)
+        for (int y = 0; y < height; y++)
         {
-            // Get current pixel value
-            QRgb pixel = image->pixel(x, y);
-            I = qGray(pixel);
+            Mode mode = Transformation::RepeatEdge;
+            int I  = qGray(getPixel(x, y, mode));
 
-            // Calculate Gx
-            Gx = Gx + (I * qGray(image->pixel(x+1, y)) - I * qGray(image->pixel(x-1, y)));
+            // Get Gx and Gy
+            Gx = qGray(getPixel(x + 1, y, mode)) - qGray(getPixel(x - 1, y, mode));
+            Gy = qGray(getPixel(x, y + 1, mode)) - qGray(getPixel(x, y - 1, mode));
 
-            //Calculate Gy
-            Gy = Gy + (I * qGray(image->pixel(x, y+1)) - I * qGray(image->pixel(x, y-1)));
-        }
-    }
-
-    // Calculate T
-    float T = (max(Gx, Gy) * I) / max(Gx, Gy);
-
-    // Iterate over pixels
-    for (int x=0; x < width; x++)
-    {
-        for (int y=0; y < height; y++)
-        {
-            // Get current pixel
-            QRgb pixel = image->pixel(x, y);
-            if(qGray(pixel) > T)
+            if (Gx > Gy)
             {
-                newImage->setPixel(x, y, Qt::color1);
+                G = Gx;
             }
             else
             {
-                newImage->setPixel(x, y, Qt::color0);
+                G = Gy;
+            }
+            numerator +=  I * G;
+            denominator += G;
+        }
+    }
+
+    T = numerator / denominator;
+
+    for (int x = 0; x < width; x++)
+    {
+        for (int y = 0; y < height; y++)
+        {
+            Mode mode = Transformation::RepeatEdge;
+            QRgb pixel = getPixel(x, y, mode);
+
+            int val = qGray(pixel);
+
+            if (val < T)
+            {
+                newImage->setPixel(x, y, 0);
+            }
+            else
+            {
+                newImage->setPixel(x, y, 1);
             }
         }
     }