Qt6 QImage never loads image but Qt5 worked

[whatabout]

I have this :

QString full_path("/home/me/image.tif");
QImage image(full_path);
if (image.isNull()) {
puts("uh oh");
} else {
QPixmap p(image);
m_label.setPixmap(p);
}

This worked fine on qt5 but in qt6 it is broken.
What happened?

[ChrisW67]

@whatabout said in Qt6 QImage never loads image but Qt5 worked:

Does anyone know how I can add that to my .pro file?

Add what to your pro file?
Just install/deploy the plugin

[ChrisW67]

@whatabout My wild guess is that you do not have a Qt TIFF image format plugin installed in whatever environment this code is being run in.

BTW: You forgot to include a lot of information in the question. For example:

• What does not work mean? Does not compile, does not run, runs but does something unexpected?
• In what environment? Windows, Linux, Mac, other
• A deployed application or in the development environment?

[whatabout]

I'm using Linux.
By not work I mean isNull() returns true.
I'm not using an IDE.
Does anyone know how I can add that to my .pro file?

[ChrisW67]

@whatabout said in Qt6 QImage never loads image but Qt5 worked:

Does anyone know how I can add that to my .pro file?

Add what to your pro file?
Just install/deploy the plugin

[Christian Ehrlicher]

And another question - how large is your image. I'm asking because of the allocationLimit.

[whatabout]

@ChrisW67 said in Qt6 QImage never loads image but Qt5 worked:

Just install/deploy the plugin

OK I see what happened. My system didn't have all qt6 packages installed for some reason.

But I'm not clear though on why plugins are being used. Was this the case with qt5?

[Christian Ehrlicher]

@whatabout said in Qt6 QImage never loads image but Qt5 worked:

Was this the case with qt5?

Maybe, maybe not - it depends on how you installed your Qt. Qt5 was modularized already in the Qt installer but Qt6 gets even more splitted to reduce the installation footprint so yes it might be the case.