How do you convert an image (PNG) to a 2D Array (binary image)?

Question

I need a 2D binary representation of the following PNG image:

Can anyone provide a method or a source to convert PNG image above to a 2D array where 1 = lan

Answer 1

Here's the relevant part if you want to access individual pixels as a 2D array

var w = canvas.width * 4;
var r,g,b;

for (var i=0; i= 164 && r <= 255) && 
        (g >= 191 && g <= 229) && 
        (b >= 220 && b <= 255)) {

      // blue  = water
      imdata[j*w+i] = 0;
      imdata[j*w+i+1] = 0;
      imdata[j*w+i+2] = 150;

    } else {

      // green = land
      imdata[j*w+i] = 0;
      imdata[j*w+i+1] = 120;
      imdata[j*w+i+2] = 0;                      
    }                   
  }
}