• Open Menu Close Menu
  • Apple
  • Shopping Bag
  • Apple
  • Mac
  • iPad
  • iPhone
  • Watch
  • TV
  • Music
  • Support
  • Search apple.com
  • Shopping Bag

Lists

Open Menu Close Menu
  • Terms and Conditions
  • Lists hosted on this site
  • Email the Postmaster
  • Tips for posting to public mailing lists
Speed up image display for large raw images?
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Speed up image display for large raw images?


  • Subject: Speed up image display for large raw images?
  • From: Marco S Hyman <email@hidden>
  • Date: Tue, 14 Aug 2012 21:58:38 -0700

Hi All,

I'm looking for some suggestions in speeding up image display.
This bit of code is called when a table view selection changes.
It can take 2-4 seconds for the image to be displayed in a
related NSImageView.

- (void) showImageForIndex: (NSInteger) ix
{
    NSImage *image = nil;
    if (ix != -1) {
        image = [[self imageAtIndex: ix] image];
        ...
    }
    [imageWell setImage: image];
}

imageWell is defined as

    IBOutlet NSImageView *imageWell;

The images are typically 25 MB Canon 7D raw image files that have
been pre-alloc'ed and initWithContentsOfFile:
The NSImageView is about 600x400 pixels.

Instruments says the time is being spent by raw image processing.
It looks like the delay is in [imageWell setImage: image];
This is logged during the delay...

Aug 14 11:50:35 dumbcat.snafu.org WindowServer[121]: CGXDisableUpdate: UI updates were forcibly disabled by application "test" for over 1.00 seconds. Server has re-enabled them.
Aug 14 11:50:37 dumbcat.snafu.org WindowServer[121]: reenable_update_for_connection: UI updates were finally reenabled by application "test" after 2.31 seconds (server forcibly re-enabled them after 1.00 seconds)

The logs show that Apple's Aperture also has long delays preparing
7D raw images for viewing. Perhaps I am just asking too much from a
2007 model iMac.

Marc
_______________________________________________

Cocoa-dev mailing list (email@hidden)

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:

This email sent to email@hidden

  • Follow-Ups:
    • Re: Speed up image display for large raw images?
      • From: Jens Alfke <email@hidden>
  • Prev by Date: Why no keyboard or mousedown events?
  • Next by Date: NSSpeechSynthesizer / DarkWake interaction
  • Previous by thread: Re: Why no keyboard or mousedown events?
  • Next by thread: Re: Speed up image display for large raw images?
  • Index(es):
    • Date
    • Thread