From: pjb@... (Pascal J. Bourguignon)
Date: 2009-03-23T08:07:05+09:00
Subject: Re: convert PNG to hex

jeljer te Wies <jeljer@me.com> writes:

> Pascal J. Bourguignon wrote:
>> jeljer te Wies <jeljer@me.com> writes:
>> 
>>>> 
>>> 100..199 for the second row etc. White pixels represent ascii codes. The 
>>> are black
>> And what's the relationship with lines and hex?
>> 
>> You want to write methods named Image.width, Image.height,
>> Image.pixelAt(x,y), Pixel.isWhite?, Pixel.isBlack?, things like that.
>
> now it is a task I would like to complete..
> The only thing I want to know is "Who many black pixels are between the 
> white pixels".
> (I have uploaded the image) ...
>
> So what i want is:
> 1) get the image in my program
> 2) get each pixel and decide if it is white or black

Well it's easy enough to do that with the methods I proposed
above. Something like:

def decode(image)
   i=0
   lastWhite=0
   bytes=[]
   (0..(image.height)).each {| y |  
      (0..(image.width)).each {| x |
         if image.pixelAt(x,y).isWhite? then
           bytes.push(i-lastWhite)
           lastWhite=i
         end
         i=i+1 
      }
   }
   bytes
end

(That's the reason why I proposed those methods).


Now you only have to implement them, doing the same: whish for methods
that would make implement the method pixelAt(x,y) easy, and do it.
Then further implement the missing methods.

-- 
__Pascal Bourguignon__