Analyse RGB file in Processing

RGB_Analyse.pde

byte bytes[]; 
int x = 0;
int y = 0;
int maxX = 431;

void setup() {
  bytes = loadBytes("zaagsel-1000000bytes.rgb");
  size(500, 1000);
}

void draw() {
  background(0);
  x=0;
  y=0;
  for (int i=0; i<bytes.length-3; ) {
    char r = char(bytes[i++] & 255);
    char g = char(bytes[i++] & 255);
    char b = char(bytes[i++] & 255);
    set(x, y, color(r, g, b));
    if (++x>maxX) {
      x=0;
      y++;
    }
  }
}

void mouseMoved() {
  maxX = mouseX;
}

void keyPressed() {
  if (keyCode==LEFT) maxX--;
  if (keyCode==RIGHT) maxX++;
  if (key==' ') println(maxX);
}