Problem when load JPG

[HelderC]

I'm trying load a jpg image, but the code doesnt works.

Look, have this:



...
QImage *img1;
QLabel *imgLbl1;


img1->load(fileName);

imgLbl1->clear();

imgLbl1->setPixmap(QPixmap::fromImage(*img1));
...


This code only works with png, gif and bmp files but doesnt with jpg.

Any advice?

Thanks.

[tbscope]

Install a jpg decoder.
Or, in other words, did you compile Qt with jpg support?

[HelderC]

I dont know. How can i "compile Qt with jpg suppot"?

[tbscope]

What Qt package did you install?

[HelderC]

I installed only Qt SDK.

[tbscope]

Check if the qt/2010.05/bin/imageFormats folder contains qjpeg4.dll

[HelderC]

Yes, its there.

[tbscope]

Change your code to use a value instead of a pointer for the image.
Example:


class YourWidgetClass
{
private:
QImage img;
};

In the constructor:

img.load(fileName);
imgLbl1->setPixmap(QPixmap::fromImage(img));

If that doesn't solve your problem, the filename is wrong.

[HelderC]

I did what you told me. But doesnt works.
Only the bmp, png and gif works....

The path is correct otherwise how can the others formats works?

[tbscope]

Very simple:
1. The code you posted is not the real code of your program? But I guess it is.
2. Back to my first reply, you do not have a jpg decoder on your computer that is able to work with Qt.

I don't understand your problem. I installed the Qt SDK and showing jpg's works for me, so it is not a Qt SDK problem, it is either a problem with your code or with your system.

[HelderC]

I think that problem is with system.
I compiled/ran the same code just now but in linux, and its works!

tbscope, thanks for your attention!

Just a last question: Why did you say to me change the *img pointers to img? Is there any problem with pointers use? How can I know when use pointer or not?

Thanks again.