Re: iPhoto-like scroll view
Re: iPhoto-like scroll view
- Subject: Re: iPhoto-like scroll view
- From: glenn andreas <email@hidden>
- Date: Sat, 8 Sep 2007 10:35:58 -0500
On Sep 8, 2007, at 10:05 AM, Chris Williams wrote:
Important note, making a thumb is expensive, you have to make them
at most
ONCE, not every time you need them. It will kill your
performance. I store
the premade thumbs in the database, don't know what you can do in your
application, but this is a must. I used the logic someone else in
this
thread noted to make the thumbs, but reading images off a disk and
scaling
them is hard work. It takes about 1-2 seconds per image. If you
have even
jut 50 in your scrollview, obviously you can't do it on the fly.
You can get much better thumbnail creation performance by using
CoreGraphic's thumbnail creation routine
CGImageSourceCreateThumbnailAtIndex, since it can be smart enough to
do things like use built in thumbnail stored in the specific image
format, and other funky trickys like rendering a JPG at a different
resolution (which is far faster than rendering it at the full
resolution and scaling it down, not to mention less memory intensive).
Glenn Andreas email@hidden
<http://www.gandreas.com/> wicked fun!
quadrium2 | build, mutate, evolve, animate | images, textures,
fractals, art
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