> On 08 Mar 2014, at 04:38, Trygve Inda <cocoa...@xericdesign.com> wrote: >> I need to composite/tile about 20 images in a 4x5 grid to one image. > > What for? Knowing that might help finding a way to speed it up. I.e. why are > the images separate, where are they supposed to go in the end? Display on > screen? Writing to a standard image file format? Something else?
The images are coming from a video file at periodic intervals and are destined for a jpg file consisting of multiple thumbnails stitched together. The CGImages come from an AVAssetImageGenerator. Instruments says the time spent in [imageGenerator copyCGImageAtTime:targetTime actualTime:&actualTime error:&error]; Is small, but the time in CGContextDrawImage is quite large. However, if I comment out the CGContextDrawImage line, then the time spent in copyCGImageAtTime it rather more significant. I imagine when I get the CGImageRef from copyCGImageAtTime, I am not actually getting any pixel data until it tries to draw in CGContextDrawImage. T. _______________________________________________ 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: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
