Hello Everyone,

I am manipulating a rectangular array pixel-by-pixel with QImage and setpixel. Next, I convert the QImage to a QPixmap, and display it through a QLabel. This process works pretty well in itself, but, I would like to be able to manipulate the image's pixels over and over, and display the "updated" Qimage (or Qpixmap) file in the label.

Right now, the QLabel remains white/blank until the for.. loop it is in, finishes. Instead, I'd like to see the changed pixmap after each 'step' within the for loop.

Any suggestions? Is there a method to successfully output the QImage in my QLabel after each loop through the step loop? The ideal result would be a Qlabel that displays the Qpixmap which, after each time through the for (step<numbstep) loop, the color is slightly modified via adjusting the R G B values. Right now, it only outputs the "final" color. (Code Below):


Qt Code: 
  1. #include "widget.h"
  2. #include "ui_widget.h"
  3. #include <QLabel>
  4. #include <iostream>
  5. #include <QImage>
  6. #include <QPixmap>
  7.  
  8.  
  9. using namespace std;
  10.  
  11.  
  12. Widget::Widget(QWidget *parent) :
  13.     QWidget(parent),
  14.     ui(new Ui::Widget)
  15. {
  16.     ui->setupUi(this);
  17.  
  18.     mylabel = new QLabel; //
  19.     mylabel->show(); //
  20.  
  21.     myimage =  QImage(100,100,QImage::Format_RGB32);
  22.  
  23.     for(int step=0;step<250;step++)
  24.     {
  25.         da = 3;db=1;dc=.5;
  26.  
  27.         for(int i=0;i<100;i++)
  28.         {
  29.             for(int j=0;j<100;j++)
  30.             {
  31.  
  32.                 QRgb colorval;
  33.                 colorval = qRgb(a,b,c);
  34.  
  35.                 myimage.setPixel(j,i,colorval);
  36.                 //cout << " Setting " << i << " " << j << endl;
  37.             }
  38.  
  39.         }
  40.         a = a + da;
  41.         b = b + db;
  42.         c = c + dc;
  43.  
  44.         QPixmap mypixmap = QPixmap::fromImage(myimage);
  45.  
  46.         mylabel->setPixmap(mypixmap);
  47.         mylabel->setScaledContents(true);
  48.         mylabel->update();
  49.  
  50.     }
  51. }
  52.  
  53. Widget::~Widget()
  54. {
  55.     delete ui;
  56. }
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