[Interest] About copying the image buffer with alpha blending

[song.7.liu at nokia.com]

QImage(const QString &fileName, const char *format = 0);

If I want to use Format_ARGB8565_Premultiplied, so what’s the format string in above constructor ?

Thanks,
Song

From: interest-bounces+song.7.liu=nokia.com at qt-project.org [mailto:interest-bounces+song.7.liu=nokia.com at qt-project.org] On Behalf Of Liu Song.7 (Nokia-MP/Beijing)
Sent: Wednesday, August 29, 2012 5:54 PM
To: till.oliver.knoll at gmail.com; interest at qt-project.org
Subject: Re: [Interest] About copying the image buffer with alpha blending

Is the premultiplied specified when creating QImage or other ?

From: interest-bounces+song.7.liu=nokia.com at qt-project.org<mailto:interest-bounces+song.7.liu=nokia.com at qt-project.org> [mailto:interest-bounces+song.7.liu=nokia.com at qt-project.org]<mailto:[mailto:interest-bounces+song.7.liu=nokia.com at qt-project.org]> On Behalf Of ext Till Oliver Knoll
Sent: Wednesday, August 29, 2012 5:04 PM
To: Qt Project
Subject: Re: [Interest] About copying the image buffer with alpha blending

Am 29.08.2012 um 09:53 schrieb <song.7.liu at nokia.com<mailto:song.7.liu at nokia.com>>:

Hi,

We found that QPainer::drawImage takes 30~50ms for one 150*114 image, it seems a little slow.

Make sure all images are using *premultiplied* alpha values when doing image compositing.

Does that help?

Cheees,
  Oliver
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