Less CPU intensive way to scan pixels

Hi -

I am scanning an image line by line and outputting the greyscale of each pixel to Pure Data via OSC, all of it is working ok but it seems super intensive for the computer, the fans are on full speed and sometimes Processing crashes a few minutes in.

Is there anything I can do to make this code less intensive? Might be missing something obvious?

It could be because of the frameRate, and if so are there any suggestions of other ways of doing this? So that I can still run the scanning pretty fast

Thanks in advance for any help

import oscP5.*;
import netP5.*;

NetAddress remote;
OscP5 oscP5;
//int incomingOSCData;
// int sendTestData;
// String msgType;

PImage img;
int x, y, s, r;

void setup() {
  size(500, 500);
  oscP5 = new OscP5(this,12000);
  remote = new NetAddress("127.0.0.1",3000);
  s = 10;
  stroke(255);
  reset();
  frameRate(200);
  img = loadImage("10.jpg");
  background(0);
  img.loadPixels();
}

void reset(){
  background(0);
  x = 0;
  y = 0;
  OscMessage msg = new OscMessage("/sync");
  msg.add(1);
  oscP5.send(msg,remote);
}

void draw() {
  if(x>=width){ y+=s; x=0; }
  if(y>=height) reset();
  delay(100);
  int loc = x + y*img.width;
  noStroke();
  color c = img.pixels[loc];
  // int alpha = (c >> 24) & 0xFF;
  int red   = (c >> 16) & 0xFF;
  int green = (c >> 8)  & 0xFF;
  int blue  =  c        & 0xFF;
  int gray = ((red + green + blue) / 3);
  // println(alpha + " " + red + " " + green + " " + blue);
  fill(c);
  rect(x++,y,4,4);
  // println(gray);
  OscMessage msg = new OscMessage("/grayscale");
  msg.add(gray);
  oscP5.send(msg,remote);
}