• 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: Fastest color detection in image?
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Fastest color detection in image?


  • Subject: Re: Fastest color detection in image?
  • From: chaitanya pandit <email@hidden>
  • Date: Fri, 26 Sep 2008 21:48:19 +0530

Well, there are 2 ways you can do it first would be to use:
NSReadPixel(apoint);
This method requires you to lock focus on the image before u call it.
You would have to iterate through every point in the image and get it's color.
But i found that this is a bit slow, to make it a bit faster you can create an NSBitmapImageRep
use [ImageRep colorAtX:apoint.x y:apoint.y] on that to get the values of color at each point, this method doesn't need a lock focus to be called on it, and its faster than the previous method i mentioned.
Perhaps if anyone knows about a faster way to do things i'd like to know as well.
hth,
Chaitanya


On 26-Sep-08, at 7:34 PM, Christian Klotz wrote:

Hi,

I'm trying to scan an image for existence of a given color. So I was wondering what the most performing way is to achieve this goal.

Basically I want to find out which amount of the given color that image has.
Furthermore, are there ways to find all regions of the image having the color? So it would be easy to show the user which parts of the image are matching.


Really appreciating any help on this.

Thanks
Christian



_______________________________________________

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

_______________________________________________

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


References: 
 >Fastest color detection in image? (From: Christian Klotz <email@hidden>)

  • Prev by Date: Re: unrecognized selector sent to instance
  • Next by Date: Re: [NSCFNumber intValue]: unrecognized selector
  • Previous by thread: Re: Fastest color detection in image?
  • Next by thread: Re: Fastest color detection in image?
  • Index(es):
    • Date
    • Thread