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  • VRoninV VRonin

    I'm surprised your compiler doesn't yell about redefinition (I probably know why but that's not the point here). I'send you to http://www.cplusplus.com/doc/tutorial/namespaces/#scopes once again

    P 離線
    P 離線
    Payx
    寫於 最後由 編輯
    #71

    @VRonin so if i want use my picture in an other function i have to declare it before my function as i did for

    QColor dominantColor(const QImage& image, const QPoint& topLeft, const QSize& rectSize);

    so i have to add a line code QImage pixi in my .cpp ?

    why not in my .h, and why

    QColor dominantColor
    

    dont work in my .h too ?

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    • VRoninV 離線
      VRoninV 離線
      VRonin
      寫於 最後由 編輯
      #72

      Ok, this has become too chatty, let's make it more structured before we both get banned.

      • Put dominantColor and fillSection code from either me or @mrjj at the top of your .cpp file, just below the #includes no need to declare them in advance in this case
      • in the private: section of your .h file add QImage m_baseImag;
      • in on_push_clicked load the image from file and store it in m_baseImag then use QPixmap::fromImage(m_baseImag) to display the image in the QLabel
      • in on_push2_clicked iterate over every 4x4 square of your picture calling the two functions:
      for (int i=0;i<m_baseImag.width();i+=4){
                 for (int j=0;j<m_baseImag.height();j+=4){
      fillSection(m_baseImag,QPoint(i,j),QSize(4,4),dominantColour(m_baseImag,QPoint(i,j),QSize(4,4)));
      }}
      
      • use QPixmap::fromImage(m_baseImag) to display the new image in another QLabel

      "La mort n'est rien, mais vivre vaincu et sans gloire, c'est mourir tous les jours"
      ~Napoleon Bonaparte

      On a crusade to banish setIndexWidget() from the holy land of Qt

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      • P 離線
        P 離線
        Payx
        寫於 最後由 Payx 編輯
        #73

        Hello,

        I have 0 error but it didn't work.

        here my code

        void MainWindow::on_push_clicked()
        {
        	QString fileName = QFileDialog::getOpenFileName(this,
        	tr("Open Image"), "/", tr("Image Files (*.png *.jpg *.bmp)"));
        	QPixmap pix(fileName);
        	ui->label->setPixmap(pix);
        	const QSize s = pix.size();
        	QImage pixi = QImage(pix.toImage());
        
        	
        
        }
        
        void MainWindow::on_push2_clicked()
        {
        	QPoint point(0,0);
        	QSize size(4,4);
        	for(int i=0;i<pixi.width();i+=4){
        		for(int j=0;j<pixi.height();j+=4){
        			fillSection(pixi,point,size,dominantColor(pixi,point,size));
        		}
        	}
        
        	QPixmap pixa=QPixmap::fromImage(pixi);
        
        	ui->label_2->setPixmap(pixa);
        }
        

        In my .h i declared

        private:
           Ui::MainWindow *ui;
           QImage pixi;
        

        pixi is the name of my picture (= m_baseImag)

        i display pixa (Qpix from pixi) in the same label as pixi (dont know if i can do that)

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        • mrjjM 離線
          mrjjM 離線
          mrjj
          Lifetime Qt Champion
          寫於 最後由 編輯
          #74

          Hi
          Good work.
          in here
          void MainWindow::on_push_clicked()
          {
          ......
          QImage pixi = QImage(pix.toImage()); // This looks like a local variable? ( die by scope)
          }

          Did you mean to use the one from .H ?

          so
          pixi = QImage(pix.toImage());

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          • P 離線
            P 離線
            Payx
            寫於 最後由 編輯
            #75

            i changed my code by using pixi = QImage(pix.toImage());

            and in my .h i got QImage pixi.

            I try to fix my rectSize to 15x15

            And my picture at the end is the same, she changed a little (she got a blue pixel in the top left

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            • VRoninV 離線
              VRoninV 離線
              VRonin
              寫於 最後由 編輯
              #76

              you never update point in your loop. it's always 0,0 it should be i,j

              "La mort n'est rien, mais vivre vaincu et sans gloire, c'est mourir tous les jours"
              ~Napoleon Bonaparte

              On a crusade to banish setIndexWidget() from the holy land of Qt

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              2
              • VRoninV VRonin

                you never update point in your loop. it's always 0,0 it should be i,j

                P 離線
                P 離線
                Payx
                寫於 最後由 Payx 編輯
                #77
                此回覆已被刪除!
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                • P 離線
                  P 離線
                  Payx
                  寫於 最後由 編輯
                  #78

                  Ok after long hours, i fixed it.

                  Thank you very much for your time in my project.

                  But i have a little question :

                  In the code it only returns Red, Blue or Green.

                  Do you have a function who return a lot of color, like if in my rect the most principal color is grey (for example) what could i do to add a lot of color ?

                  At the end i will have a picture more pixelated but that i can recognize

                  kshegunovK 1 條回覆 最後回覆
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                  • mrjjM 離線
                    mrjjM 離線
                    mrjj
                    Lifetime Qt Champion
                    寫於 最後由 編輯
                    #79

                    Hi

                    • if in my rect the most principal color is grey

                    That is just values for R,G,B. still.

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                    • VRoninV 離線
                      VRoninV 離線
                      VRonin
                      寫於 最後由 VRonin 編輯
                      #80

                      Modify dominantColour with this one. It takes the most frequent colour that appears in the square and fills it with it

                      QColor dominantColour(const QImage& image,const QPoint& topLeft, const QSize& rectSize){
                      	const int maxRight = qMin(image.width(),topLeft.x() + rectSize.width());
                      	const int maxBottom = qMin(image.height(),topLeft.y() + rectSize.height());
                      	QHash<QColor,int> colourMap;
                      	for(int x=topLeft.x();x<maxRight;++x){
                      		for(int y=topLeft.y();y<maxBottom;++y){
                      			const QColor tempColor=image.pixelColor(x,y);
                      			auto colourIter=colourMap.find(tempColor);
                      			if(colourIter==colourMap.end())
                      				colourMap.insert(tempColor,1);
                      			else
                      				colourIter.value()++;
                      		}
                      	}
                      	if(colourMap.isEmpty())
                      		return Qt::black;
                      	return std::max_element(colourMap.constBegin(),colourMap.constEnd()).key();
                      }
                      

                      "La mort n'est rien, mais vivre vaincu et sans gloire, c'est mourir tous les jours"
                      ~Napoleon Bonaparte

                      On a crusade to banish setIndexWidget() from the holy land of Qt

                      1 條回覆 最後回覆
                      1
                      • P Payx

                        Ok after long hours, i fixed it.

                        Thank you very much for your time in my project.

                        But i have a little question :

                        In the code it only returns Red, Blue or Green.

                        Do you have a function who return a lot of color, like if in my rect the most principal color is grey (for example) what could i do to add a lot of color ?

                        At the end i will have a picture more pixelated but that i can recognize

                        kshegunovK 離線
                        kshegunovK 離線
                        kshegunov
                        Moderators
                        寫於 最後由 編輯
                        #81

                        I suggest you average the color in the rectangle, e.g. (thanks to @VRonin for the scaffolding):

                        QColor dominantColour(const QImage & image,const QPoint & topLeft, const QSize & rectSize)
                        {
                            qint32 averageRed = 0, averageGreen = 0, averageBlue = 0;
                        
                            const qint32 maxX = qMin<qint32>(image.width(), topLeft.x() + rectSize.width());
                            const qint32 maxY = qMin<qint32>(image.height(), topLeft.y() + rectSize.height());
                            for (qint32 y = topLeft.y(); y < maxY; y++)  {
                                for (qint32 x = topLeft.x(); x < maxX; x++)   {
                                    QRgb pixel = image.pixel(x, y);
                                    
                                    averageRed += qRed(pixel);
                                    averageGreen += qGreen(pixel);
                                    averageBlue += qBlue(pixel);
                                }
                            }
                        
                            qint32 n = rectSize.width() * rectSize.height();
                        
                            Q_ASSERT(n);
                            if (n <= 0)
                                return Qt::black;
                        
                            return QColor(averageRed / n, averageGreen / n, averageBlue / n);
                        }
                        

                        Read and abide by the Qt Code of Conduct

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                        • P 離線
                          P 離線
                          Payx
                          寫於 最後由 編輯
                          #82

                          Thank you very much !

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