function __construct()
{
// set default values for properties
$this->chmod_value = 0755;
$this->error = 0;
$this->jpeg_quality = 85;
$this->png_compression = 9;
$this->preserve_aspect_ratio = $this->preserve_time = $this->enlarge_smaller_images = true;
$this->sharpen_images = $this->auto_handle_exif_orientation = false;
$this->source_path = $this->target_path = '';
}