size(200, 200);
  colorMode(RGB, width);
  
  int[] hist = new int[width];
  
  // Load an image from the data directory
  // Load a different image by modifying the comments
  PImage a;
  a = loadImage("cdi01_g.jpg");
  image(a, 0, 0);
  
  // Calculate the histogram
  for (int i=0; i<width; i++) {
    for (int j=0; j<height; j++) {
      hist[int(red(get(i, j)))]++; 
    }
  } 
  
  // Find the largest value in the histogram
  float maxval = 0;
  for (int i=0; i<width; i++) {
    if(hist[i] > maxval) {
      maxval = hist[i];
    }  
  }
  
  // Normalize the histogram to values between 0 and "height"
  for (int i=0; i<width; i++) {
    hist[i] = int(hist[i]/maxval * height);
  }
  
  // Draw half of the histogram (skip every second value)
  stroke(width);
  for (int i=0; i<width; i+=2) {
    line(i, height, i, height-hist[i]);
  }