Change application color to grayscale

[alexsho]

Is it possible to define programmatically the color depth of the Qt application window to 8 bit grayscale ?
The final goal is to get the QPixmap of the application window directly in grayscale for my further processing, instead of converting it on the fly, spending a lot of CPU time.

[Chris Kawa]

I don't think there's anything like that in Qt.
How often do you capture the pixmap and how large is it?

[alexsho]

I have to capture the window each time something changes, so probably it will be in the PaintEvent.