[Qt-interest] How can I read a large image fastly?

[Lorenzo Masini]

Il giorno gio, 04/02/2010 alle 21.16 +0800, Kermit Mei ha scritto:  
> Thanks, Cheers. But in fact, what I want to know is not how to paint it 
> fast, I want to know how can I load it more fast.
> 
> This paintEvent() is just a test routine, and it just load only one 
> time.  In another words, I want to know how to improve the speed of 
> "imgReader->read()". And why I can't load just part of it?

I don't know how you can read exactly the piece of image you are looking
for, but you can use async I/O to don't freeze the interface.

You can try to read a chunk of image per time and append it to a QBuffer
for example, and than do the stuff you want.

I don't know if it will load the image faster, but it should make the
interface more responsive.


Cheers
Lorenzo