On 1 Nov 2011, at 01:44, Arbit Richardi wrote: > I'm looking for tips to speed image drawing on OS X — this is a > primary function of my application. I started out naively with > NSImage, switched to CGImage, tried layer backing, and now draw > directly into a hosted layer with Quartz. I have an implementation > using CATiledLayers but it doesn't add speed in common cases. > > At this point, large images still draw significantly slower than in > Preview. For example, I can display a 25MB test JPEG (~9k x 9k pixels) > in ~2 seconds while Preview can display it in ~1 second on the same > machine. I can display a 12MB raw (~4k x 3k) in ~2.5 seconds while > Preview can display it in less than 1 second. > > In my code, almost all that time is spent in CGContextDrawImage() — > not something I can optimize. > > Looking at rendering the test JPEG in Instruments, I can see that > Preview's call tree is largely the same as my call tree except that > Preview uses some sort of custom tiling.
I'm pretty certain Preview is using IKImageView, or at least it used to. > > Looking at the rendering the test raw in Instruments, the primary > difference is that my code calls a specific RawCamera function three > times more than Preview calls it. What this means, I don't know. > > I've combed the documentation, the internet, and the list archives > pretty thoroughly and I feel like I'm about out of things to try. Can > anyone give me advice or leads? > > Thanks > _______________________________________________ > > Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) > > Please do not post admin requests or moderator comments to the list. > Contact the moderators at cocoa-dev-admins(at)lists.apple.com > > Help/Unsubscribe/Update your Subscription: > http://lists.apple.com/mailman/options/cocoa-dev/cocoadev%40mikeabdullah.net > > This email sent to cocoa...@mikeabdullah.net _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
