How to use Pixmap::fromImage() in Jpeg data.

[DaTranShan]

Hi there, I have a data stream in a struct transform from another thread and I want to Load it and show it.

QImage((uchar*)pbyteImage,1024,1024,2,QImage::Format_RGB32);
this->setPixmap(QPixmap::fromImage(img_in));

The question is which the Format should I use?
I will be grateful for your replies.

[jsulm]

@DaTranShan said in How to use Pixmap::fromImage() in Jped data.:

The question is which the Format should I use?

The one you get from the stream I would say. You should know what format is used to put the data into the stream.

[DaTranShan]

Sorry about that I missed that, which is Jpeg buffer size 102410242 in uint32. I can understand 1024*1024 is the size of that. But 2 which means ?

[DaTranShan]

102410242

[DaTranShan]

1024 x 1024 x 2

[SGaist]

Hi,

Since it's jpeg data, shouldn't you be using QImage::fromData ?

[DaTranShan]

@SGaist Yeah!!! Thank you, sir. I used

            QImage img_in;
            img_in.loadFromData(pbyteImage,size,"JPG");

Load the pic normally. As I thought, QImage maybe could use his constructor loading the pic. Do you know how can I use that? Or that can't do that, but Why? Thank you for that.

[DaTranShan]

@jsulm Hi jsulm, according to @SGaist advice I could use QImage.loadFromData function to load the pic. But I still think the QImage constructor could do that too. Do you think so, and how can I do that? Sincerely thanks for your replies.

[jsulm]

@DaTranShan You can use static QImage::fromData method:

QImage img_in = QImage::fromData(pbyteImage,size,"JPG");

If you insist in using one of the constructors (for whatever reason) there are some of them described in the documentation (like https://doc.qt.io/qt-5/qimage.html#QImage-3) - did you check already?