Qt Draw fast png images

[anafor2004]

Hi All ;
I am developing an embedded project for my graduate project. I have to use an image on my UI. But my systems processor is ARM9 and system have to be very fast so i doubt that what is the best solution , drawing this picture on UI or draw this image by QTs functions. Which is the best solution.

[aamer4yu]

Isnt your UI based on Qt ?
Just try the image example on ur ARM device and see if it works fine...

[anafor2004]

aamer4u,
I already use Qt as G.U.I but I wonder that what is the fastest way to show an image draw by codes ("paint and draw functions") or draw as a image (".png,.jpeg.....")?

[wysota]

It depends what you want to draw. But basically all drawing in Qt is double buffered, so if you draw with painter functions, it will get blitted to the framebuffer later anyway. This might reduce the benefit of not painting all pixels. I'd say in most situations blitting a ready image is faster.

[anafor2004]

Dear Wysota,
Thanks for your reply, but i wonder that now i am using my Qt on embedded development project .There is an Arm9 MC on my development board. Qt works very slow, because I show many png images in QLabels.When I change the pages (QStacked widgets), it takes too much time. I draw that images via QPaintEvent() function. Is it a good way to draw images via QPaintevent()?. How May I speed up drawing images? Are there any other faster ways drawing .png images in QLabels?