Picture

[Payx]

Okay i fixed it

MainWindow::MainWindow(QWidget *parent) :
	QMainWindow(parent),
	ui(new Ui::MainWindow)
{
		ui->setupUi(this);

}
QColor dominantColor(const QImage& image, const QPoint& topLeft, const QSize& rectSize);
void fillSection(QImage& image, const QPoint& topLeft, const QSize& rectSize, const QColor& colour);

MainWindow::~MainWindow()
{
	delete ui;
}

So now with, fillSection, the problem i have is to declare something who correspond to QColor& colour

i check the code again, and i think its colourList no ?

[VRonin]

sorry if don't listen to you very well but

No worries, I'm explicitly refraining from giving you the exact answer and rather trying to send you on the right path.

i check the code again, and i think its colourList no ?

Nope, colourList will die: http://www.cplusplus.com/doc/tutorial/namespaces/#scopes

[Payx]

@VRonin said in Picture:

Nope, colourList will die: http://www.cplusplus.com/doc/tutorial/namespaces/#scopes

Ok i got it, we will put the returned color from QColor dominantColor, thats right ?

[VRonin]

Getting warmer and warmer

[Payx]

I got :

QColor domicolor=dominantColor(pixi,point,size);

The returned color is "domicolor", so i put domicolor in :

void fillSection(pixi, point, size, domicolor);

[VRonin]

sooo close!
http://www.cplusplus.com/doc/tutorial/functions/#void

[Payx]

I call her with just :

fillSection(pixi,point,size,domicolor);

[VRonin]

@Payx Bingo!

[Payx]

I try to change the rectSize with 100 x 100.

my first function is :

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());

	ui->label_2->setText( "Size: " + QString::number(s.width()) +" "+ QString::number(s.height()) );

}

It load an image with an explorer file.

But the picture dont change at all when i click on the push2

[VRonin]

I did not say you were done, just that you were on the right path.

from the code you posted it's clear you did not grasp scoping 100% so i'll repost the link: http://www.cplusplus.com/doc/tutorial/namespaces/#scopes

pix and pixi die as soon as MainWindow::on_push_clicked() terminates

[Payx]

@VRonin Yes but in my .h i add QImage pixi thats not correct?

[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

[kshegunov]

@VRonin said in Picture:

I'm surprised your compiler doesn't yell about redefinition

Not redefinition, shadowing, hence no yelling. :)

[VRonin]

@kshegunov said in Picture:

shadowing

The case @kshegunov is explaining is in the 3rd code block of the link above:

// inner block scopes
#include <iostream>
using namespace std;

int main () {
  int x = 10;
  int y = 20;
  {
    int x;   // ok, inner scope.
    x = 50;  // sets value to inner x
    y = 50;  // sets value to (outer) y
    cout << "inner block:\n";
    cout << "x: " << x << '\n';
    cout << "y: " << y << '\n';
  }
  cout << "outer block:\n";
  cout << "x: " << x << '\n';
  cout << "y: " << y << '\n';
  return 0;
}

This means I should go back to that tutorial myself

[Payx]

@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 ?

[VRonin]

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

[Payx]

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)

[mrjj]

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());

[Payx]

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

[VRonin]

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