QImage to QPixmap where should I add scale() If I want to set to QLable

mrjj

@darrenleeleelee1
Hi
hmm, I cant guess why.
for me, it clearly ignores the AspectRatio.

Maybe your picture is perfectly square?

darrenleeleelee1

@mrjj no, It's(2235, 3408)

mrjj

@darrenleeleelee1

ok.

what are
photo.width() and self.photo.height()

darrenleeleelee1

@mrjj (512, 512)

mrjj

@darrenleeleelee1

Hi
I tried with the same sizes as you, found image at (2235, 3408) also

alt text

So not why you always seems to see the same.

What Qt version are you using ?

darrenleeleelee1

@mrjj

You use scale for QImage not QPixmap?

mrjj

@darrenleeleelee1

Hi
Yes.

{
    qimage = qimage.scaled(ui->label->width(),ui->label->height(), Qt::KeepAspectRatio, Qt::SmoothTransformation);
    auto pixmap = QPixmap::fromImage(qimage);
    ui->label->setPixmap(pixmap);
    }

darrenleeleelee1

@mrjj What is the different if I am scale to QPixmap

mrjj

@darrenleeleelee1

Hi
as far as I know, nothing.
Both return a scaled copy.

I cant see anything wrong with the code you shown. So unless its a bug in 5.9.7
i really have no idea why the images look the same to you.

Also, you scale it down a lot so there should always be an effect.

darrenleeleelee1

@mrjj OK, thanks, I found I was not put two Image together like you do.And I miss the change.Thanks you alot.Sorry bother you.

mrjj

@darrenleeleelee1

ahh. Well that explains why they look so much the same :)
No worries, its no bother at all.