A few questions

1. I want to create curves using difference mapping and Gsvideo. Is it possible to have the camera running and my application reading from the camera w/o actually displaying the output of the camera to the screen? i.e. do I have to put cam in img or could I

  video = new GSCapture(this, width, height, 24);
loadPixels

and have it read the camera actively?

2. when I'm looping through pixels using my loops if (int i = 0; i < pixels.length; i++) {pixels[i].extra y and x value}

each pixels stores its x and y value where? When pixels[i] comes up, how can I extract the x and y values from the pixels or is that not stored in the pixel array and processing simply starts at 0,0 and iterates to the last pixel?
is there a pixel[i][0] with the x value and a pixels[i][1] with the Y value?

Sorry about that, the size of the array is the size of the window... gotcha... hence pixels[0] x = 0 y = 0 etc. it does wrap around correct i.e. pixels[1] x = 1 y = 0 pixels[2] x = 2 y = 0

I'm sorry if my questions are naive, but I'm a bit of a beginner.

3. Extra bonus question: I delcare int[] coords = {540, 320};
in my set up, when I tried to call it in the draw draw method I get an error, no such thing as coods.

Here is my code so far (I'm just trying to mod the original GSvideo example):

/**
 * Getting Started with Capture.
 *
 * GSVideo version by Andres Colubri.
 *
 * Reading and displaying an image from an attached Capture device.
 */
import codeanticode.gsvideo.*;

GSCapture cam;

void setup() {
  size(640, 480);


  /*
  // List functionality still not ready on Linux
  String[] cameras = GSCapture.list();
 
  if (cameras.length == 0)
  {
    println("There are no cameras available for capture.");
    exit();
  } else {
    println("Available cameras:");
    for (int i = 0; i < cameras.length; i++)
      println(cameras[i]);
    cam = new GSCapture(this, 320, 240, cameras[0]);
  }

  However, different cameras can be selected by using their device file:
  cam = new GSCapture(this, 640, 480, "/dev/video0");
  cam = new GSCapture(this, 640, 480, "/dev/video1");
  etc.
  */
  int[] coords = {540, 300}; // when I try to push pixels[i] value to this array in draw, I get no such thing as coords
  cam = new GSCapture(this, 640, 480);

}

void draw() {
  if (cam.available() == true) {
    cam.read();// turn this into a variable and then read from it.
    loadPixels();
    image(cam, 0, 0);
    int halfImage = width*height/2;
    color pink = color(255, 102, 204);
    loadPixels();
    for (int i = 0; i < halfImage; i++) {
    color currColor = pixels[i];
    int currR = (currColor >> 16) & 0xFF;
    int currG = (currColor >> 8) & 0xFF;
    int currB = currColor & 0xFF;
    int places = pixels[i];
    beginShape();
// this is where my little curve will begin
// if possible I just want to draw the shape and not display the camera image
    endShape();
    }
    updatePixels();
    // color currColor = video.pixels[i];
    // image(cam, x in box, y in box);
    // The following does the same, and is faster when just drawing the image
    // without any additional resizing, transformations, or tint.
    // set(160, 100, cam);
  }
}