In this little bit of code I experimented with get(x, y):

 

PImage someImage;

void setup()
{
  size(100, 155);
  background(192);
  noLoop();
  someImage = loadImage(" http://processing.org/img/learning/books/getting-started-with-processing-sm.jpg");
}

void draw()
{
//  image(someImage, 0, 0, 50, 77); //red value is red(background)
  image(someImage, 0, 0); //red value is 238
  //if I comment both out, I get the value of the background colour
  println(red(get(55, 100)));
}

 

Can I find the colour of a pixel in an image without displaying the image?