scriptime

// Get the image info from the photo
$image_info = getimagesize($photo);
$width = $new_width = $image_info[0];
$height = $new_height = $image_info[1];
$type = $image_info[2];

// Load the image
switch ($type)
{
    case IMAGETYPE_JPEG:
        $image = imagecreatefromjpeg($photo);
        break;
    case IMAGETYPE_GIF:
        $image = imagecreatefromgif($photo);
        break;
    case IMAGETYPE_PNG:
        $image = imagecreatefrompng($photo);
        break;
    default:
        die('Error loading '.$photo.' - File type '.$type.' not supported');
}

// Create a new, resized image
$new_width = 180;
$new_height = $height / ($width / $new_width);
$new_image = imagecreatetruecolor($new_width, $new_height);
imagecopyresampled($new_image, $image, 0, 0, 0, 0, $new_width, $new_height, $width, $height);

// Save the new image over the top of the original photo
switch ($type)
{
    case IMAGETYPE_JPEG:
        imagejpeg($image, $photo, 100);
        break;
    case IMAGETYPE_GIF:
        imagegif($image, $photo);         
        break;
    case IMAGETYPE_PNG:
        imagepng($image, $photo);
        break;
    default:
        die('Error saving image: '.$photo);
}