• 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
Re: Determining if images are roughly equal
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Determining if images are roughly equal


  • Subject: Re: Determining if images are roughly equal
  • From: Dave Camp <email@hidden>
  • Date: Mon, 3 Feb 2003 13:59:58 -0800

I think QuickTime may have an API for checking for image similarity. Look in the headers/docs or try posting the question on one of the QT lists.

Dave

On Monday, February 3, 2003, at 01:38 PM, John C. Randolph wrote:

I think I should mention that Image Difference only presents a *visual* representation of the difference between images. What I had in mind was to see how much was lost between versions of an image that had varying levels of compression. There's no code in there to quantify that difference (like the way that DVD encoders do the sum-of-absolute-difference thing.)

-jcr

On Saturday, February 1, 2003, at 08:58 AM, Joe Osborn wrote:

Apple recently posted sources to ImageDifference, a tool for subtracting images from each other-- here's a link:

http://developer.apple.com/samplecode/Sample_Code/Graphics_2D/
Image_Difference.htm

It's handy, I'm gonna use it for something soon, too.

Can someone suggest a method for roughly comparing NSImages? I am creating a disk caching mechanism for my app, and I need a way to check if an image downloaded from the web (could be in any format) is equal to an NSImage I've created from a PNG on disk.

...

-Jan Van Tol



--joie

"If you are new to Vi and Vim, using 'nocompatible' is strongly recommended, because Vi has a lot of unexpected side effects, which are avoided by this setting." -- Vim manual

John C. Randolph <email@hidden> (408) 974-8819
Sr. Cocoa Software Engineer,
Apple Worldwide Developer Relations
http://developer.apple.com/cocoa/index.html
_______________________________________________
cocoa-dev mailing list | email@hidden
Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/cocoa-dev
Do not post admin requests to the list. They will be ignored.


---
There's an old proverb that says just about whatever you want it to.
_______________________________________________
cocoa-dev mailing list | email@hidden
Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/cocoa-dev
Do not post admin requests to the list. They will be ignored.

References: 
 >Re: Determining if images are roughly equal (From: "John C. Randolph" <email@hidden>)

  • Prev by Date: Hidden Objects
  • Next by Date: Re: Hidden Objects
  • Previous by thread: Re: Determining if images are roughly equal
  • Next by thread: NSArray problems
  • Index(es):
    • Date
    • Thread