Picture

[VRonin]

ok, now we are making progress. you got what the dominant colour is, now you have to paint the rectange

[Payx]

@VRonin said in Picture:

ok, now we are making progress. you got what the dominant colour is, now you have to paint the rectange

sorry if don't listen to you very well but

it say that my function isnt declared (dominantColor)

[VRonin]

http://www.cplusplus.com/doc/tutorial/functions/#declarations

[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)