PHP Create thumbnail of an image

<?php

/*
Title: Create thumbnail of an image in PHP

PHP SCRIPT to create thumbnail of any image. This works for .jpg, .gif and .png files as well. 

$source  parameter expects path & file name of original image
$thumbnail_path  expects the path & file name where thumbnail is to be stored
$thumbnail_width is the width of the resulting thumbnail
$thumbnail_height is the height of the thumbnail

*/
function createImageThumbnail($source, $thumbnail_path, $thumbnail_width, $thumbnail_height, $background=false) {
	
	// Get dimensions of original image
    list($image_width, $imagel_height, $original_type) = getimagesize($source);
	
	// Set dimensions of the thumbnail
    if ($image_width > $imagel_height) {
        $new_width = $thumbnail_width;
        $new_height = intval($imagel_height * $new_width / $image_width);
    } else {
        $new_height = $thumbnail_height;
        $new_width = intval($image_width * $new_height / $imagel_height);
    }
	
	
    $dest_x = intval(($thumbnail_width - $new_width) / 2);
    $dest_y = intval(($thumbnail_height - $new_height) / 2);


// Depending on the fact if original image is GIF, JPEG or PNG, we use respective GD functions
    if ($original_type === 1) {
        $imgt = "ImageGIF";
        $imgcreatefrom = "ImageCreateFromGIF";
    } else if ($original_type === 2) {
        $imgt = "ImageJPEG";
        $imgcreatefrom = "ImageCreateFromJPEG";
    } else if ($original_type === 3) {
        $imgt = "ImagePNG";
        $imgcreatefrom = "ImageCreateFromPNG";
    } else {
        return false;
    }


// Load the original image
    $old_image = $imgcreatefrom($source);
    $new_image = imagecreatetruecolor($thumbnail_width, $thumbnail_height); // creates new image, but with a black background

    // If background color parameter is provided, then use it
    if(is_array($background) && count($background) === 3) {
      list($red, $green, $blue) = $background;
      $color = imagecolorallocate($new_image, $red, $green, $blue);
      imagefill($new_image, 0, 0, $color);
	  
    // For PNG files use, we make their backgroung transparent
    } else if($background === 'transparent' && $original_type === 3) {
      imagesavealpha($new_image, TRUE);
      $color = imagecolorallocatealpha($new_image, 0, 0, 0, 127);
      imagefill($new_image, 0, 0, $color);
    }

// Create final thumbnail image.
    imagecopyresampled($new_image, $old_image, $dest_x, $dest_y, 0, 0, $new_width, $new_height, $image_width, $imagel_height);
    $imgt($new_image, $thumbnail_path);
    return file_exists($thumbnail_path);
}  // End of Create thumbnail of an image function 


// This is path of the image file for which thumbnail is to be generated
// Make sure image one.jpg exists in folder image. 
$source="image/one.jpg";
// Folder named thumb should exist. Because thumbnail image will be stored here
$destination="thumb/one.jpg";

// Set height and width of the thumbnail
$thumbnail_width=200;
$thumbnail_height=200;

// Call the function with the above paraters. It will just create an thumbnail and on success return and echo 1.
echo createImageThumbnail($source, $destination, $thumbnail_width, $thumbnail_height);

?>