Zadanie_03_ready

src/core/histogram.cpp

@@ -25,7 +25,7 @@ Histogram::~Histogram()
 void Histogram::generate(QImage* image)
 {
 
-  qDebug() << Q_FUNC_INFO << "Not implemented yet!";
+  qDebug() << Q_FUNC_INFO << " Generating histogram !";
     for(int i = 0 ; i < image->height(); i++){
         for(int j = 0 ; j < image->width() ; j++){
             QColor *clrCurrent = new QColor( image->pixel(i,j) );
@@ -35,18 +35,88 @@ void Histogram::generate(QImage* image)
             L->insert(clrCurrent->alpha(),R->value(clrCurrent->alpha())+1);
         }
     }
-
-
-
-    qDebug() << Q_FUNC_INFO << "Not implemented yet!";
 }
 
 /** Returns the maximal value of the histogram in the given channel */
 int Histogram::maximumValue(Channel selectedChannel = RGB)
 {
-    qDebug() << Q_FUNC_INFO << "Not implemented yet!";
+    int max = 0;
+    if(selectedChannel == LChannel){
+        return getMaxFromQHashHelper(get(selectedChannel));
+    }
 
-    return 0;
+    max = getMaxFromQHashHelper(R);
+
+    if(getMaxFromQHashHelper(G) >  max){
+        max = getMaxFromQHashHelper(G);
+    }
+
+    if(getMaxFromQHashHelper(B) >  max){
+        max = getMaxFromQHashHelper(B);
+    }
+
+    return max;
+}
+
+// Return max or -1  when QHash is empty
+int Histogram::getMaxFromQHashHelper( QHash<int, int>  * channel ){
+    int max = -1;
+
+    QHash<int, int>::const_iterator iterator = channel->begin();
+    while (iterator != channel->end())
+    {
+       if(iterator.value()  > max){
+           max = iterator.value();
+       }
+        ++iterator;
+
+    }
+    return max;
+}
+
+int Histogram::getMaxKey( QHash<int, int>  * channel ){
+    int max = -1;
+
+    QHash<int, int>::const_iterator iterator = channel->begin();
+    while (iterator != channel->end())
+    {
+       if(iterator.key()  > max){
+           max = iterator.key();
+       }
+        ++iterator;
+
+    }
+    return max;
+}
+
+int Histogram::getMinKey( QHash<int, int>  * channel ){
+    int min = 256;
+
+    QHash<int, int>::const_iterator iterator = channel->begin();
+    while (iterator != channel->end())
+    {
+       if(iterator.key() < min){
+           min = iterator.key();
+       }
+        ++iterator;
+
+    }
+    return min;
+}
+
+//Return min or 256 when qhash is empty
+int Histogram::getMinFromQHashHelper( QHash<int, int>  * channel ){
+    int min = 256;
+
+    QHash<int, int>::const_iterator iterator = channel->begin();
+    while (iterator != channel->end())
+    {
+       if(iterator.value()  < min){
+           min = iterator.value();
+       }
+        ++iterator;
+    }
+    return min;
 }
 
 

src/core/histogram.h

@@ -16,10 +16,15 @@ public:
     QHash<int, int>* get(Histogram::Channel);
     QImage           getImage(Histogram::Channel, QBrush);
     int              maximumValue(Channel);
+    int              getMaxFromQHashHelper( QHash<int, int> *);
+    int              getMinFromQHashHelper( QHash<int, int> *);
+    int              getMinKey( QHash<int, int> *);
+    int              getMaxKey( QHash<int, int> *);
 
 private:
     void generate(QImage*); // iterates all parent image pixels and set the Hashes
 
+
     QHash<int, int>* R;
     QHash<int, int>* G;
     QHash<int, int>* B;

src/core/transformations/histogram_stretching.cpp

@@ -14,13 +14,41 @@ HistogramStretching::HistogramStretching(PNM* img, ImageViewer* iv) :
 
 PNM* HistogramStretching::transform()
 {
+       qDebug() << Q_FUNC_INFO << "START";
     int width  = image->width();
     int height = image->height();
 
     PNM* newImage = new PNM(width, height, image->format());
+    Histogram * histogram = image->getHistogram();
 
-    qDebug() << Q_FUNC_INFO << "Not implemented yet!";
+    int  maxRed = histogram->getMaxKey(histogram->get(histogram->RChannel));
+    int  minRed = histogram->getMinKey(histogram->get(histogram->RChannel));
 
+    int  maxGreen = histogram->getMaxKey(histogram->get(histogram->GChannel));
+    int  minGreen = histogram->getMinKey(histogram->get(histogram->GChannel));
+
+    int  maxBlue = histogram->getMaxKey(histogram->get(histogram->BChannel));
+    int  minBlue = histogram->getMinKey(histogram->get(histogram->BChannel));
+
+    int  maxAlpha = histogram->getMaxKey(histogram->get(histogram->LChannel));
+    int  minAlpha = histogram->getMinKey(histogram->get(histogram->LChannel));
+
+     qDebug() << Q_FUNC_INFO << "LOOP";
+    for(int x  = 0 ; x < width; x++){
+        for (int y = 0 ; y < height; y++) {
+
+           QRgb pixel = image->pixel(x,y);
+           int g = (qGreen(pixel) - minGreen) * (MAX_VALUE/(maxGreen-minGreen));
+           int r = (qRed(pixel) - minRed) * (MAX_VALUE/(maxRed-minRed));
+           int b = (qBlue(pixel) - minBlue) * (MAX_VALUE/(maxBlue-minBlue));
+      //     int a = (qAlpha(pixel) - minAlpha) * (MAX_VALUE/(maxAlpha-minAlpha));
+
+            qDebug() << Q_FUNC_INFO << "1. Here is working !!";
+          QRgb  blee =   QColor(r,g,b).rgba();
+            qDebug() << Q_FUNC_INFO << "2. Here is workingt too  !!";
+           newImage->setPixel(x,y,QColor(r,g,b).rgba());
+        }
+    }
     return newImage;
 }
 

src/core/transformations/histogram_stretching.cpp.autosave

@@ -0,0 +1,48 @@
+#include "histogram_stretching.h"
+
+#include "../histogram.h"
+
+HistogramStretching::HistogramStretching(PNM* img) :
+    Transformation(img)
+{
+}
+
+HistogramStretching::HistogramStretching(PNM* img, ImageViewer* iv) :
+    Transformation(img, iv)
+{
+}
+
+PNM* HistogramStretching::transform()
+{
+       qDebug() << Q_FUNC_INFO << "START";
+    int width  = image->width();
+    int height = image->height();
+
+    PNM* newImage = new PNM(width, height, image->format());
+    Histogram * histogram = image->getHistogram();
+
+    int  maxRed = histogram->getMaxKey(histogram->get(histogram->RChannel));
+    int  minRed = histogram->getMinKey(histogram->get(histogram->RChannel));
+
+    int  maxGreen = histogram->getMaxKey(histogram->get(histogram->GChannel));
+    int  minGreen = histogram->getMinKey(histogram->get(histogram->GChannel));
+
+    int  maxBlue = histogram->getMaxKey(histogram->get(histogram->BChannel));
+    int  minBlue = histogram->getMinKey(histogram->get(histogram->BChannel));
+
+
+     qDebug() << Q_FUNC_INFO << "LOOP";
+    for(int x  = 0 ; x < width; x++){
+        for (int y = 0 ; y < height; y++) {
+
+           QRgb pixel = image->pixel(x,y);
+           int g = (qGreen(pixel) - minGreen) * (MAX_VALUE/(maxGreen-minGreen));
+           int r = (qRed(pixel) - minRed) * (MAX_VALUE/(maxRed-minRed));
+           int b = (qBlue(pixel) - minBlue) * (MAX_VALUE/(maxBlue-minBlue));
+           newImage->setPixel(x,y,QColor(r,g,b).rgba());
+        }
+    }
+    return newImage;
+}
+
+

src/core/transformations/histogram_stretching.h

@@ -6,6 +6,7 @@
 class HistogramStretching : public Transformation
 {
 public:
+    int const MAX_VALUE = 255;
     HistogramStretching(PNM*);
     HistogramStretching(PNM*, ImageViewer* iv);