First lesson - JPEG image manipulation with PHP

php-jpeg-glitch.php

<?php
// loop 100 times
for ($j = 0; $j < 100; $j++) {

  // open a file called some-file.jpg
  // and store its data in a variable
  $image = file_get_contents('./some-file.jpg');

  // loop 10 times
  for ($i = 0; $i < 10; $i++ ) {
    // change some data in the data of the image
    $image[($i * rand(800, 1000) ) + 1525] = 'ª¶§∞£tuy';
  }

  // save the data to a new file
  // to make it unique, add a 'timestamp' in miliseconds
  file_put_contents('./some-result-' . microtime(true) . '.jpg', $image);

}

// file end makes program end

To run this, save the above in a file in a specific directory (folder). Put an image in the same folder. Change the name of the file to some-file.jpg or change to code above to reflect the image's name.
Open the Terminal application and cd into the directory. For example:
cd Desktop/glitch
Run the program:
php php-jpeg-glitch.php
Open Finder and look what the result of your glitching is.