Bulk image resize with PHP

<?php
/* 
*This is the parent directory where all the files you want to resize, 
* including the sub-directories and the files in them are all located 
*/
define('UPLOADED_FILES_BASE_DIRECTORY', 'uploads');

/* 
* This is the width that all the resized files will have depending on their aspect ratio
*/
define('RESIZE_FILES_TO_width', '700');


/* 
* This is the height that all the resized files will have depending on their aspect ratio
*/
define('RESIZE_FILES_TO_height', '700');

// Aspect ration of each file is calculated using the width and height of the file
?>

Before a file can be resized or compressed, the system will first of all check the original size (width/height) of the image file comparing this size to your given size (width/height), if your given size are greater than the original size of the file, the system will compress the file using the original size of the file to maintain the aspect ratio of the file but if your given size are less than the original size of the file then the system will compress the file using your given size.