qImage saving to jpg problem

[sqarpi]

Hello again.
I have problems with saving qImage to jpg.
On the very begining i was trying to use QPixmap::save() like this:

QString saveFile=QFileDialog::getSaveFileName(this,tr("save"),QDir::homePath());
    if(!saveFile.isEmpty())
        if(!tlo->save(saveFile,".JPG",100));

QString saveFile=QFileDialog::getSaveFileName(this,tr("save"),QDir::homePath());
    if(!saveFile.isEmpty())
        if(!tlo->save(saveFile,".JPG",100));

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but it didn't work(no errors, just was not saving file), so i have tried qimagewriter and... on the one computer it's working on the other not... the code is:

QString saveFile=QFileDialog::getSaveFileName(this,tr("save"),QDir::homePath());
    if(!saveFile.isEmpty()){
        QImageWriter writer(saveFile);
        writer.write(*tlo);
        if(writer.canWrite())
            qDebug("i can write");
        else
            qDebug("i can't write");
        qDebug()<< writer.errorString();
    }

QString saveFile=QFileDialog::getSaveFileName(this,tr("save"),QDir::homePath());
    if(!saveFile.isEmpty()){
        QImageWriter writer(saveFile);
        writer.write(*tlo);
        if(writer.canWrite())
            qDebug("i can write");
        else
            qDebug("i can't write");
        qDebug()<< writer.errorString();
    }

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it shows me "i can write" co there is no problems with opening file to write and no problems with qimage... the error line is "unknown problem"
any ideas about the solution? any ideas why save() didn't work? i really will appreciate help.
thank

[Lykurg]

Make sure you have the jpeg plugin on the right place that your app can find it.

[wysota]

The format name is "JPG" or "JPEG" and not ".JPG".

[sqarpi]

The format name is "JPG" or "JPEG" and not ".JPG".

Thanks, fixed, but save() still doesn't work. It gives me true as return, but dosn't save the file.

[wysota]

Check the path, maybe it saves the image in a different directory than you expect.

[sqarpi]

That would be the idea, but it takes path from QFileDialog. Anyway, can't find such file in any directory. Doesn't matter with save. Just why on one computer i have problems with QImageWriter, on the other not. Same Qt 4.6.0 from same instalation files, different OS - winxp(works) win764b(doesn't work).

[wysota]

That would be the idea, but it takes path from QFileDialog.

And that makes it impossible to dump it to the console?

[sqarpi]

qDebug(saveFile.toLatin1)

qDebug(saveFile.toLatin1)

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shows correct path.

[wysota]

So check if the location is writable to the current user, etc. Also dump QImageWriter::supportedImageFormats() to the console.

[sqarpi]

That's it. Opening program as an administrator helped, but funny, i didn't have such problems with writing a text to file.
Thanks mates for the brainstorm.