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Re: How to read pixel values of monochrome images
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Re: How to read pixel values of monochrome images


  • Subject: Re: How to read pixel values of monochrome images
  • From: "John C. Randolph" <email@hidden>
  • Date: Sat, 23 Aug 2008 20:55:11 -0700


On Aug 23, 2008, at 2:51 PM, Shawn Erickson wrote:

On Fri, Aug 22, 2008 at 2:54 AM, Eduardo Areitio <email@hidden> wrote:
I'm trying to read individual pixel values in a monochrome image using
NSReadPixel, but I haven't been able to.


I would much appreciate anyone's help

It is usually best to post some code or better explain what you tried and what is going wrong otherwise we have to guess at the difficulty you are having.

Anyway...

http://developer.apple.com/samplecode/Color_Sampler/listing5.html

You'll notice from the comments in that sample, that NSReadPixel() gets a value from the graphics context that has the current drawing focus. If you're trying to read a value from an image, you've got to have somewhere to draw it first.


-jcr

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  • Follow-Ups:
    • Re: How to read pixel values of monochrome images
      • From: Jean-Daniel Dupas <email@hidden>
References: 
 >How to read pixel values of monochrome images (From: Eduardo Areitio <email@hidden>)
 >Re: How to read pixel values of monochrome images (From: "Shawn Erickson" <email@hidden>)

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