HELP PLEASE- Superimpose two images in a QPixmap

[ChrisW67]

Zero in the alpha channel makes a pixel totally transparent, and 1.0 (255 when expressed as 8 bit int) makes it totally opaque.

I gather you want a partly transparent top image to be drawn over the bottom image.

QImage top("top.jpg");
QImage bot("bottom.jpg");
// both images are opaque because JPEG has no alpha channel
 
QPixmap combined(bot.size());
QPainter p(&combined);
p.drawImage(QPoint(0, 0), bot); // drawn as-is
p.setOpacity(0.2);
p.drawImage(QPoint(0, 0), top);  // drawn at 20% opacity
p.end();

QImage top("top.jpg");
QImage bot("bottom.jpg");
// both images are opaque because JPEG has no alpha channel

QPixmap combined(bot.size());
QPainter p(&combined);
p.drawImage(QPoint(0, 0), bot); // drawn as-is
p.setOpacity(0.2);
p.drawImage(QPoint(0, 0), top);  // drawn at 20% opacity
p.end();

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