create GIF animations from a folder of images at any length of frames

gifcompiler.pde

import gifAnimation.*;

GifMaker gifExport;

static int FRAME_RATE = 30;
//Select a folder to process:, It must contain images with filename '1.jpg, 2.jpg,3.jpg,etc.
String PATH = "/Users/bmoren/Desktop/GifFrames/"; //make sure there is a "/" at the end of the filepath
//how many files to process?
int IMAGE_NB = 1; // first in sequence (or where to start?)
int TOTAL = 1644 ; //how many in forlder (or to go up to?)

public void setup() {
  size(32, 32);
  frameRate(FRAME_RATE);
  gifExport = new GifMaker(this, "export.gif");

  // make it a looping animation
  gifExport.setRepeat(0); 

  /* make white the transparent color. EVERY white pixel in the animation will be transparent.
   * GIF doesn't have alpha like processing. a pixel can only be totally transparent or totally opaque.
   *
   * set the processing background and the transparent gif color to the same value as the gifs destination background color 
   * (e.g. the website bg-color). Like this you can have the antialiasing from processing in the gif.*/
  //gifExport.setTransparent(255, 255, 255);
}


void draw() {
  background(255);

    if (IMAGE_NB < TOTAL) {
      image(loadImage(PATH + IMAGE_NB++ + ".jpg"), 0, 0);
      gifExport.setDelay(1000/FRAME_RATE);
      gifExport.addFrame();
    } else {
      image(loadImage(PATH + IMAGE_NB++ + ".jpg"), 0, 0);
      gifExport.setDelay(1000/FRAME_RATE);
      gifExport.addFrame();
      gifExport.finish();
      println("Finished! Exporting...");
      exit();
    }
  }

https://extrapixel.github.io/gif-animation/
Processing 2